Category Archives: Remote sensing

Why Stephen Hawking Was Afraid of Aliens

Young Stephen Hawking.

Professor Stephen Hawking, the theoretical physicist hailed as one of the most brilliant scientists of the modern age, had genuine anxieties. Thus, intelligence does not necessarily reject fear. Hawking had one fear in particular which deserves noting, namely humanity’s encounter with advanced alien life.

Several of the late physicist’s theories have been shown to be quite accurate and are widely accepted in the scientific community. When he spoke (through his speech synthesizer) people gave ear and were attentive. Like any man, he too had his faults both public and personal. But simply because the man has passed away, does not mean we should disregard what he did and said during his time on Earth.

He made numerous predictions about the present and future problems that the human race faces, involving issues such as overpopulation and artificial intelligence. Perhaps one of his most intriguing and logically-stated beliefs was a concern for detrimental interaction between human beings and extraterrestrial beings.

Unlike astrophysicist Carl Sagan, who was rather optimistic about extraterrestrial contact, Hawking worried about the effects such contact might have on our race, even though the Professor assisted in founding projects to seek intelligent alien organisms. Some may fear aliens as they are depicted in sci-fi and horror stories: ugly creatures capable of taking over human beings and using them as their hosts.

The physical appearance of hypothetical aliens is not what alarmed Stephen Hawking. It was something a bit more sinister. In short, he apparently was cautious of entertaining alien contact because of the possibility that intelligent alien civilizations may want to dominate our race. They might do this either by enslaving people or slaughtering them, or both.

He has related these concerns publicly as early as 2010. In 2016, he speculated that if Earth received a signal of alien origins “we should be wary of answering back.” He further argued this point by employing historical references. “Meeting an advanced civilization could be like Native Americans encountering Columbus,” he said. “That didn’t turn out so well.” Sometime in the future, if we’re not cautious in the search for alien life, humans might rue ignoring Stephen Hawking’s worries about extraterrestrials.

LS1 is the the farthest individual star scientists have ever witnessed. Right panels: region of the sky from 2011 when LS1 wasn't visible and the same patch in 2016 when gravitational lensing enabled observation. Credit: P. Kelly, University of Minnesota/NASA/ESA.

Astronomers find the most distant star ever, looking through a galactic magnifying glass

A stroke of good fortune allowed astronomers to image a bright dot located a staggering 9 billion light-years away. This is the farthest star scientists have ever identified — more than 100 times more distant than any other lone star previously detected. Amazingly, the light we’re currently picking up first shot from the surface of the star ‘only’ 4.4 billion years after the Big Bang.

LS1 is the the farthest individual star scientists have ever witnessed. Right panels: region of the sky from 2011 when LS1 wasn't visible and the same patch in 2016 when gravitational lensing enabled observation. Credit: P. Kelly, University of Minnesota/NASA/ESA.

LS1 is the farthest individual star scientists have ever witnessed. Right panels: region of the sky from 2011 when LS1 wasn’t visible and the same patch in 2016 when gravitational lensing enabled observation. Credit: P. Kelly, University of Minnesota/NASA/ESA.

Typically, when astronomers image cosmic objects  such distances, they are very bright bodies like supernovae or galaxy clusters. How could a single, puny star shine as bright as a supernova (the most powerful explosions in the universe)? We just got very lucky — that’s all.

Thanks to a fortuitous cosmic alignment that enabled gravitational lensing, the star in question, called MACS J1149+2223 Lensed Star 1 (LS1), was magnified by a factor of 2,000. Famed physicist Albert Einstein predicted, as a result of his Theory of General Relativity, that whenever light from a distant star passes by a closer object, gravity acts like a magnifying lens bending the distant starlight but also brightening it. This effect has been documented extensively around very massive structures such as galaxies.

Initially, Patrick L. Kelly, an astrophysicist at the University of Minnesota, and colleagues were studying a supernova explosion in the galaxy cluster MACS J1149.5-223 when they picked up a strange blip that appeared in the same galaxy as the supernova. Since this first episode in April 2016, the astronomers were able to use the Hubble Space Telescope to image the hot blue star, which was magnified by a massive cluster of galaxies — the lens of the magnifying glass.

According to spectral measurements, LS1 is an extremely luminous and blue B-type supergiant star, whose surface temperature sits between 11,000 and 14,000 degrees Celsius. That’s more than twice as hot as the sun’s surface.

The astronomers were very lucky that the hot star passed right along the critical curve of the cluster, warping the starlight in our direction and enabling observations at unprecedented distances for a lone star. This effect is like a natural telescope, more powerful than anything we could ever build, according to Kelly.

LS1 will help scientists gain new insights into the constituents of the galaxy cluster. So far, Kelly’s team thinks the microlensing was caused by either a star, a neutron star, or a stellar-mass black hole. Learning about the constituents of galaxy clusters — some of the largest and most massive structures in the universe — will consolidate the science that studies the composition and evolution of the universe. And, as is often the case with such research, dark matter is always lurking.

“If dark matter is at least partially made up of comparatively low-mass black holes, as it was recently proposed, we should be able to see this in the light curve of LS1. Our observations do not favour the possibility that a high fraction of dark matter is made of these primordial black holes with about 30 times the mass of the Sun”, highlights Kelly.

Whatever the case may be, it’s quite amazing to look back in time at three-quarters of the universe’s age — all thanks to starlight and weird physics. In the future, coupling the same gravitational lensing technique with a far more powerful space telescope than Hubble — the upcoming James Webb Telescope — should allow scientists to peer ever further back in time.

The findings appeared in the journal Nature Astronomy.

NASA creates stunning visualization of melting snowflake

For the first time, researchers have created a 3D numerical model of melting snowflakes in the atmosphere. Aside from just painting a pretty, scientifically accurate picture, this could also help scientists develop better weather models and predictions.

This model reproduces key features of melting snowflakes that have been observed in nature: first, meltwater gathers in any concave regions of the snowflake’s surface. These liquid-water regions merge as they grow and eventually form a shell of liquid around an ice core, finally developing into a water drop. Credit: NASA.

If there’s anything this winter has taught us, it’s that weather is still surprising. Weather predictions have come a long way, but the sheer complexity of all the elements involved makes it very difficult to create accurate models — one of those elements which adds complexity is snow.

Snow not only affects weather predictions, but it also affects remote sensing. For instance, a radar “profile” of the atmosphere will typically show a very bright layer at the altitude where falling snow and hail melt — much brighter than atmospheric layers above and below it. We don’t really know why this happens, and we don’t understand many things about how snow starts to melt high up in the atmosphere. This is where NASA’s Jussi Leinonen enters the stage.

Leinonen created a melting model for snowflakes. He started his model by observing snowflakes in nature and noting the different melting stages. First, the outer parts start to melt, creating a bit of liquid water. This meltwater gathers in any concave regions it can find, and then the different droplets merge to form a liquid shell around the ice core. Ultimately, this melted core develops into a water drops, as can be seen above.

Although snowflakes notoriously have different intricate forms, the process seems to carry out similarly, regardless of what the shape might be.

While this isn’t the first model of snow melting, it’s by far the most accurate. This improvement could lead to significant improvements in several fields of research. Taking into consideration the individual dynamics of individual snowflakes can help researchers better understand the cryosphere — the collection of the Earth’s ice sheets, glaciers, sea ice, snow cover, and permafrost.

In 2018, NASA will launch two new satellite missions, conducting an array of field research that will enhance our understanding of the Earth’s cryosphere.

The paper, titled “Snowflake melting simulation using smoothed particle hydrodynamics,” recently appeared in the Journal of Geophysical Research – Atmospheres.


Hunt for planets through Kepler’s data with this newly released Google code

If you’ve ever dreamt of trying your hand at hunting exoplanets, a new bit of code could make your wish come true.


Image via Wikimedia.

Yesterday, we told you about the power of citizen science in biology — today, researchers are back to enlist us mere Muggles in the search for new worlds. It all started back in December, when a pair of NASA researchers reported the discovery of two, previously overlooked, alien planets after dredging through NASA’s archived data from the Kepler program. What made this discovery possible was software built around Google’s machine-learning systems, whose architecture and function mimics that of the human brain.

Motherboard astronomy

Get your hard drive limber and your internet connection fired up because that same computer program (AstroNet) was released for public use just a few days ago. You can access it, along with instructions detailing how to use it, on GitHub.


“We’re excited to release our code for processing the Kepler data, training our neural network model and making predictions about new candidate signals,” wrote lead author of that December discovery study and Google senior software engineer Chris Shallue in a blog post on March 8th.

“We hope this release will prove a useful starting point for developing similar models for other NASA missions, like [Kepler’s second mission] and the upcoming Transiting Exoplanet Survey Satellite mission,” he added.

Telescopes, Kepler included, detect alien worlds by spying on the tiny dips in brightness they cause when passing in front of their host stars — also referred to as the planets ‘transiting’ their host. Because the sky is littered with stars, software is used to automatically flag the most promising dimming events, which are then manually investigated by researchers looking for planets. Some flaggings turn out to be false positives, caused by events such as a body passing exactly in the right point of space to mimic the dimming of a transiting planet.

Given the sheer amount of stars researchers have to work with, that initial, automated sieving is vital to NASA. Our systems are only as fail-proof as we are (to be read: not very), so intriguing worlds can and do sometimes slip through undetected. Shaulle and his co-author, University of Texas astronomer Andrew Vanderburg, discovered one such planet using the machine-learning-sporting software. Their planet is the eighth in the Kepler-90 system, which lies — to the extent you can use that term in space — some 2,545 light-years away from Earth. The discovery was quite significant, as it’s only the second solar system known to harbor eight or more planets; the other one being our own.

Shaulle and Vanderburg only had to go through 670 stars to find the two new exoplanets — for context, Kepler looked at roughly 150,000 stars during its first (K1) mission, from 2009 to 2013. To that number, add thousands more it observed during the K2 phase, during which it took a more narrow approach to planet-hunting. The K2 phase started after a malfunction to the Kepler telescope’s reaction wheels, heavy wheels that maintain its orientation. Essentially, researchers can’t steer the craft properly any longer — so they’re taking advantage of the situation to just look at whatever it happens to be pointing at.

While Kepler might be limping, that juicy database of stars it’s already looked at is still available.

“It’s possible that some potentially habitable planets like Earth, which are relatively small and orbit around relatively dim stars, might be hiding just below the traditional detection threshold — there might be hidden gems still undiscovered in the Kepler data!” Shallue added in his post.

So if you’ve ever fancied discovering a planet, download AstroNet and grab a warm cup of tea while your PC does the heavy lifting.  Who knows, maybe NASA will let you name something you discover. So let’s show them the power of citizen science.

Let’s make Planet McPlanetface a thing!


New NASA data reveals many of Jupiter’s hidden secrets

A series of four papers using data from NASA’s Juno mission reveals intriguing information about Jupiter, including its gravitational field, its atmospheric flows, its interior composition and its polar cyclones.

Jupiter’s winds are tightly connected to the planet’s gravitational and magnetic fields. Image credits: NASA / ESA / UC Berkeley.

When the Juno mission was successfully launched in 2011, astronomers worldwide were thrilled. The shuttle had the potential to reveal valuable information about Jupiter and its satellites — and that potential has been thoroughly fulfilled. The new papers are the latest in a long chain of remarkable findings about the most massive planet in our solar system, adding some much-needed pieces to the puzzle.

In the first paper, researchers led by Luciano Iess of the Sapienza University of Rome in Italy used Doppler data to study Jupiter’s gravitational field. The data allowed researchers to measure Juno’s velocity down to 0.01mm/s accuracy, even while the shuttle is traveling at speeds of up to 70 km/s in orbit.

Jupiter’s gravitational field is famously asymmetrical, which is unusual for fast-rotating and oblate (squashed at the poles) gas giants. This gravitational asymmetry is caused by hydrogen-rich gas is flowing asymmetrically deep in the planet, and Juno was able to study this process.

This picture of the Jupiter’s South Pole is a mosaic of many images acquired by the Jovian InfraRed Auroral Mapper on board the Juno shuttle. The images have been taken in different times while Juno was leaving the planet after the closest approach. What you see here is the heat (measured as radiance) coming out from the planet through the clouds: yellow indicates the presence of thinner clouds and dark red the thicker ones.

Two other papers looked at different physical parameters of Jupiter. A team led by Yohai Kaspi of the Weizmann Institute of Science in Israel used another asymmetry, that of Jupiter’s magnetic field, to calculate the depth of Jupiter’s atmosphere, finding that the mass of the atmosphere amounts for about 1% of the planet’s total mass. Meanwhile, Tristan Guillot and co-authors report that at depths greater than 3,000 kilometers below cloud level, Jupiter’s deep interior is made up of a fluid mixture of hydrogen and helium, rotating as a solid body. They also found that the speed of the above-mentioned winds extend some 3,000 km beneath the cloud level, dropping in intensity with altitude.

Even with all this information, we’re still just barely scratching the surface of what we know about Jupiter.

“We’re at the beginning of dissecting Jupiter,” says Juno mission leader Scott Bolton of the Southwest Research Institute in San Antonio.

However, there’s also a downside to the Juno mission: it offered so much valuable data that it’s gonna be very hard to top it. In an accompanying News&Views article, planetary scientist Jonathan Fortney of the University of California Santa Cruz praised the work, writing:

“The work demonstrated here is extremely robust,” Fortney wrote in his editorial. “I do not foresee another leap in knowledge on Jupiter’s interior after the Juno mission ends, unless astronomers are able to study the planet’s internal oscillations, as has been done for the Sun.”

Fortunately, Juno will remain in orbit for at least a couple of years, so we’ll certainly have more to learn about Jupiter.

Journal References:

  1. Measurement of Jupiter’s asymmetric gravity field. Corresponding Author: Luciano Iess (Sapienza Università di Roma, Rome, Italy). DOI: 10.1038/nature25776.
  2. Jupiter’s atmospheric jet streams extend thousands of kilometres deep. Corresponding Author: Yohai Kaspi (Weizmann Institute of Science, Rehovot, Israel). DOI: 10.1038/nature25793.
  3. A suppression of differential rotation in Jupiter’s deep interior. Corresponding Author: Tristan Guillot (Université Côte d’Azur, Nice, France). DOI: 10.1038/nature25775.
  4. Clusters of cyclones encircling Jupiter’s poles. Corresponding Author: Alberto Adriani (INAF-Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy). DOI: 10.1038/nature25491.

Large, previously unknown penguin colony discovered through satellite

During the past years, the total number of Adélie Penguins has been steadily declining. But thanks to the advent of remote sensing technologies, researchers have found a new supercolony of more than 1,500,000 individuals.

After the satellite, researchers used drones to count the penguins. Image credits: T. S. McChord / H. Singh /NU / WHOI.

Danger Island

The first clues came in 2014 when researchers observed large patches of guano (their poo) contrasting with the mostly white, snowy background. Heather Lynch, Associate Professor of Ecology & Evolution at Stony Brook University, and her colleague Mathew Schwaller, from NASA, were curious to see what the source of the guano was, so they contacted Stephanie Jenouvrier, a seabird ecologist at WHOI, Mike Polito at LSU and Tom Hart at Oxford University. Together, they started planning an expedition, but there was a problem: their destination was Danger Islands.

The Danger Islands were discovered on 28 December 1842 by a British explorer called James Clark Ross, who named them thusly due to the heavy fragments of ice concealed which “guard” the island. Even during the summer, the islands are extremely dangerous and difficult to explore. But, since the Landsat satellites don’t have a high enough resolution to properly describe the colony, they needed to get closer.

The researchers found that the Danger Islands have 751,527 pairs of Adélie penguins–more than the rest of the entire Antarctic Peninsula region combined. They include the third and fourth largest Adélie penguin colonies in the world. Image credits: Michael Polito, Louisiana State University.

So in December 2015, they finally managed to get on ground and start the count. To get a clear image of the colony and to avoid disturbing the birds, they used drones which flew above the penguins and took detailed photos.

“The drone lets you fly in a grid over the island, taking pictures once per second. You can then stitch them together into a huge collage that shows the entire landmass in 2D and 3D,” says co-PI Hanumant Singh, Professor of Mechanical and Industrial Engineering at Northeastern University, who developed the drone’s imaging and navigation system.

The drones flew grids above the penguins. Credits: C. Youngflesh / SBU.

Large and healthy

Researchers found that  theDanger Islands host a whopping 751,527 pairs of Adélie penguins, including the third and fourth largest colonies in the world. But here’s the thing: not only have they found an incredible number of penguins, but these penguins seem unfazed by the woes of other populations.

“Not only do the Danger Islands hold the largest population of Adélie penguins on the Antarctic Peninsula, they also appear to have not suffered the population declines found along the western side of Antarctic Peninsula that are associated with recent climate change,” study co-author Michael Polito, an assistant professor at Louisiana State University, said in a statement. 

The Adélie penguins, which measure 46 to 71 cm (18 to 28 in) in height and 3.6 to 6 kg (7.9 to 13.2 lb) in weight, have been under significant pressure from warming temperatures and diminishing ice ranges. A 2016 study found that a third of current Adélie colonies may be in decline by 2060, and approximately 60 percent of the present population might be dwindling by 2099. It’s hard to say exactly what is causing their decline, but it’s likely a sum of factors related to temperature shifts.

This graphic shows changes to the suitability of Adélie penguin breeding areas. New colonies not featured. Credit: NASA’s Goddard Space Flight Center.

“It’s hard to know the causes. Clearly, climate change and reduction in ice and krill play a part, but a decline in sea-ice also allows in shipping – fisheries in particular – which may exacerbate the problem,” adds Jenouvrier.

“In the past we’ve looked at this on the West Antarctic Peninsula versus places like Elephant Island (further to the north). Finally getting into the Danger Islands and counting the penguins shows how robust populations are where the ice is intact.”

Furthermore, having an accurate count allows researchers to better understand the situation and challenges of the species, and will improve the accuracy of future countings. But it also adds new questions which researchers hope to answer in the future.

“The population of Adélies on the east side of the Antarctic Peninsula is different from what we see on the west side, for example. We want to understand why. Is it linked to the extended sea ice condition over there? Food availability? That’s something we don’t know,” she says.

Journal Reference: Alex Borowicz et al. ‘Multi-modal survey of Adélie penguin mega-colonies reveals the Danger Islands as a seabird hotspot’. doi:10.1038/s41598-018-22313-w

Three Old Scientific Concepts Getting a Modern Look

If you have a good look at some of the underlying concepts of modern science, you might notice that some of our current notions are rooted in old scientific thinking, some of which originated in ancient times. Some of today’s scientists have even reconsidered or revamped old scientific concepts. We’ve explored some of them below.

4 Elements of the Ancient Greeks vs 4 Phases of Matter

The ancient Greek philosopher and scholar Empedocles (495-430 BC) came up with the cosmogenic belief that all matter was made up of four principal elements: earth, water, air, and fire. He further speculated that these various elements or substances were able to be separated or reconstituted. According to Empedocles, these actions were a result of two forces. These forces were love, which worked to combine, and hate, which brought about a breaking down of the elements.

What scientists refer to as elements today have few similarities with the elements examined by the Greeks thousands of years ago. However, Empedocles’ proposed quadruplet of substances bares resemblance to what we call the four phases of matter: solid, liquid, gas, and plasma. The phases are the different forms or properties material substances can take.

Water in two states: liquid (including the clouds), and solid (ice). Image via Wikipedia.

Compare Empedocles’ substances to the modern phases of matter. “Earth” would be solid. The dirt on the ground is in a solid phase of matter. Next comes water which is a liquid; water is the most common liquid on Earth. Air, something which surrounds us constantly in our atmosphere, is a gaseous form of matter.

And lastly, we come to fire. Fire has fascinated human beings for time beyond history. Fire is similar to plasma in that both generate electromagnetic radiation such as light. Most flames you see in your everyday life are not hot enough to be considered plasma. They are typically considered gaseous. A prime example of an area where plasma is formed is the sun. The ancient four elements have an intriguing correspondent in modern science.

Ancient Concept of Dome Sky vs. Simulation Hypothesis

Millennia ago, people held the notion that his world was flat. Picture a horizontal cooking sheet with a transparent glass bowl set on top of it. Primitive people thought of the Earth in much the same way. They considered the land itself as flat and the sky as a dome. However, early Greek philosophers such as Pythagoras (c. 570-495 BC) — who is also known for formulating the Pythagorean theorem — understood that Earth was actually spherical.

Fast forward to the 21st century. Now scientists are considering the scientific concept of the dome once again but in a much more complex manner.

Regardless of what conspiracy lovers would have you believe, the human race has ventured into outer space, leaving the face of the Earth to travel to the stars. In the face of all our achievements, some scientists actually question if reality is real, a mindboggling and apparently laughable idea.

But some scientists have wondered if we could be existing in a computer simulation. The gap between science and science fiction starts to become very fine when considering this.

This idea calls to mind classic sci-fi plots such as those frequently played out in The Twilight Zone in which everything the characters take as real turns out to be something entirely unexpected. You might also remember the sequence in Men in Black in which the audience sees that the entire universe is inside an alien marble. Bill Nye even uses the dome as an example in discussing hypothetical virtual reality. This gives one the feeling that he is living in a snowglobe.

Medieval Alchemy vs. Modern Chemistry

The alchemists of the Middle Ages attempted to prove that matter could be transformed from one object into an entirely new object. One of their fondest goals they wished to achieve was the creation of gold from a less valuable substance. They were dreaming big, but such dreams have not yet come to fruition. Could it actually be possible to alter one type of matter into another?

Well, modern chemists may be well on their way to achieving this feat some day. They are pursuing the idea of converting light into matter, as is expressed in Albert Einstein’s famous equation. Since 2014, scientists have been claiming that such an operation would be quite feasible, especially with extant technology.

Einstein’s famous equation.

Light is made up of photons, and a contraption capable of performing the conversion has been dubbed “photon-photon collider.” Though we might not be able to transform matter into other matter in the near future, it looks like the light-to-matter transformation has a bright outlook.

Jodrell Bank.

Jodrell Bank, Earth’s oldest radio telescope, nominated as UNESCO Site

The earliest surviving radio observatory in the world has been nominated to join the ranks of UNESCO’s world heritage sites.

Jodrell Bank.

Image credits Flickr user sharing user info with oath is wrong.

The giant dishes of the Jodrell Bank Observatory, as well as the auxiliary buildings surrounding them, have been nominated by the British Government as an UNESCO world heritage site. Work performed at the Observatory in the early days of the space age changed our understanding of the universe and made possible man’s first tentative steps towards the stars.

The march of progress

The complex is part of the University of Manchester and was founded in 1945 when Sir Bernard Lovell decided to move his laboratory here so he could get some peace and quiet away from the radio interference of the city. It’s now the earliest surviving radio astronomy observatory in the world, and the site (still operational) includes a hodge-podge of structures inherited from every phase of development in this field of research.

“The Jodrell Bank Observatory, and Lovell Telescope in particular, have become icons of science and engineering around the world,” says Professor Teresa Anderson, director of the discovery center at Jodrell Bank.

The center has been working on making a case for nomination for several years now, and Professor Anderson says they’re “delighted to reach this milestone.”

Standing just under 90 meters tall, the Lovell Telescope was the first of its kind in the world. It’s still the third largest today, and Historic England (HE) already gave it — and the more recent Mark II telescope beside it — a grade I listing. However, last August, HE also listed the group of buildings (they’re mostly glorified sheds) surrounding the telescopes. This included Lovell’s 1950s control room and the electrical workshop which served as the site’s office, library, and lecture room. HE’s listing was announced to mark the 60-year anniversary since the telescope started operations.

The site is rich in scientific history. The Lovell telescope tracked the first artificial satellite, USSR’s Sputnik I, making its way around the planet. It’s the single remaining site worldwide that has been a working observatory since the earliest days of radio astronomy, and the only one to include evidence of all stages of the post-1945 development of radio astronomy.

In recognition of all these facts, Jodrell Bank will be put forward to become UK’s 32nd world heritage site, sometime in 2019.

“The nomination process for Unesco is rightly thorough,” says heritage minister Michael Ellis, “but I believe Jodrell Bank deserves to be recognised.”

If designated, it would join the likes of Australia’s Great Barrier Reef, the Great Wall of China and the Grand Canyon in the US as sites with outstanding value to the world.

Crowdsourcing astronomy: Citizen scientists discover new rocky planets locked in resonance

It’s easier than ever to contribute to science, and this study proves it best. Amateur astronomers using an online platform have discovered five rocky planets orbiting a far-off star.

To make things even more exciting, the planets are orbiting in an interesting mathematical relationship called a resonance chain — every planet takes 50% longer to orbit than the previous one.

Artist’s concept of a top-down view of the K2-138 system discovered by citizen scientists, showing the orbits and relative sizes of the five known planets. Orbital periods of the five planets, shown to scale, fall close to a series of 3:2 mean motion resonances. This indicates that the planets orbiting K2-138, which likely formed much farther away from the star, migrated inward slowly and smoothly. Credit: NASA/JPL-Caltech.

Citizen scientists

In March 2017, the initial prototype of Exoplanet Explorers was set up on Zooniverse, a citizen science web portal headquartered at Oxford University. Exoplanet Explorers had amateur astronomers analyze data from NASA’s Kepler telescope trails — it was data which had never been analyzed by astronomers. Just 48 hours after the project was launched, researchers had received 2 million classifications from more than 10,000 users.

“People anywhere can log on and learn what real signals from exoplanets look like, and then look through actual data collected from the Kepler telescope to vote on whether or not to classify a given signal as a transit, or just noise,” said co-author Dr Jessie Christiansen, from Caltech in Pasadena.

The system required several people to look at the data and indicate an interesting objective.

“We have each potential transit signal looked at by a minimum of 10 people, and each needs a minimum of 90 percent of ‘yes’ votes to be considered for further characterization,” Christiansen.

After going through the entire dataset, scientists analyzed the demographics of the discovered planets: 44 Jupiter-sized planets, 72 Neptune-sized, 44 Earth-sized, and 53 so-called Super Earth’s — rocky planets larger than Earths but smaller than Neptune.

An artist’s depiction of K2-138. This is brutally inaccurate, as all five planets are in close proximity to the host star. There’s no way water would exist on the surface, as portrayed here. Come on NASA, you’re better than this. (Image: NASA/JPL-Caltech).

Astronomers were thrilled to see that among the finds there was a system of five planets, all of which were slightly larger than Earth, ranging between 1.6 and 3.3 times the radius of Earth. The planets are locked in a phenomenon called orbital resonance. This means that there’s a simple mathematical relationship between the planets’ orbital periods. In this case, it’s 3:2 — each planet’s orbit is 50% longer than the previous one. This resonance chain of five planets is the longest one ever discovered, though other chains have also been discovered.

“The clockwork-like orbital architecture of this planetary system is keenly reminiscent of the Galilean satellites of Jupiter,” says Konstantin Batygin, assistant professor of planetary science and Van Nuys Page Scholar, who was not involved with the study. “Orbital commensurabilities among planets are fundamentally fragile, so the present-day configuration of the K2-138 planets clearly points to a rather gentle and laminar formation environment of these distant worlds.”

Space music

This unusual relationship gets even more interesting. Data also revealed a sixth planet, still in resonance, but which it skips two slots in the resonance chain. This might indicate a missing planet, or it might indicate another, unknown process.

It’s even more intriguing that this resonance coincides with a perfect fifth, an interval found commonly found in music. However, the interval isn’t exactly perfect. Instead of the ratio being exactly 1.5 (3:2), it’s 1.513, 1.518, 1.528, and 1.544 respectively. This yields another similarity to music, where musicians often tune their instruments just slightly off from a perfect-fifth to avoid the annoying “beat” that occurs when the tuning is too perfect.

The planets are locked in orbital resonance — like a musical perfect fifth. Image via Wikipedia.

Even so, the most interesting thing about these planets is the way they were found. Nowadays, there’s just too much available data and not enough researchers to look at it. Algorithms are also limited in their scope. Having the sheer brain processing power of thousands of volunteers is simply irreplaceable.

“It’s really hard to tell the computer to find everything that looks like a blip, but not ‘that’ kind of blip or ‘that’ kind of blip or ‘that’ kind of blip. So we just tell the computer to find all the blips and we’ll check.”

“We just uploaded 55,000 new potential planetary signals,” Christiansen says. “We would never be able to get through all of the signals we have without our volunteers.”

The study was published in the online edition of The Astronomical Journal.

Supermassive black holes eventually stop star formation

Researchers analyzed the correlation between the mass of supermassive black hole and the history of star formation in its galaxy. They found that the bigger the black hole is, the harder it is for the galaxy to generate new stars.

Scientists have been debating this theory for a while, but until now, they lacked enough observational data to prove or disprove it.

Via Pixabay/12019

Researchers from the University of Santa Cruz, California used data from previous studies measuring supermassive black hole mass. They then used spectroscopy to determine how stars formed in galaxies featuring such gargantuan black holes and correlate the two.

Spectroscopy is a technique that relies on measuring the wavelength of light emerging from objects — stars, in this case. The paper’s lead author Ignacio Martín-Navarro used computational analysis to determine how the black holes affected star formation — in a way, he tried to solve a light puzzle.

“It tells you how much light is coming from stellar populations of different ages,” he said in a press release.

Via Pixabay / imonedesign.

Next, the research team plotted the size of supermassive black holes and compared them to a history of star formation in that galaxy. They found that as the black holes grew more and more, star formation was significantly slowed down. Other characteristics of the galaxies, such as shape or size, were found irrelevant to the study.

“For galaxies with the same mass of stars but different black hole mass in the center, those galaxies with bigger black holes were quenched earlier and faster than those with smaller black holes. So star formation lasted longer in those galaxies with smaller central black holes,” Martín-Navarro said.

Star gas from Carina Nebula, source: Pixabay/skeeze

Scientists still trying to determine why this happens. One theory suggests that the lack of cold gas is the main culprit for reduced star formation. The supermassive black holes suck in the nearby gas, creating high-energy jets in the process. These jets ultimately expel cold gas from the galaxy. Without enough cold gas, there is no new star formation, so the galaxy becomes practically sterile.

In the press release, co-author Aaron Romanowsky concluded:

“There are different ways a black hole can put energy out into the galaxy, and theorists have all kinds of ideas about how quenching happens, but there’s more work to be done to fit these new observations into the models.”

The paper was published in Nature on the 1st of January 2018.

Ever wanted to see how far apart the Earth and the Moon are? Well, now you can

The distance between the Earth and the moon is 384,400 km (240,000 miles) — we’re taught that in high school, and even if we don’t know it, it’s always easy to look up on the internet. But knowing and comprehending that distance are two entirely different things. Now, you can truly see it, thanks to this image from NASA’s OSIRIS-REx spacecraft.

At the time this image was taken, the spacecraft was retreating from Earth after performing an Earth Gravity Assist maneuver on Sept. 22. Earth and the Moon are shown 249,000 miles (401,200 kilometers) apart, and the spacecraft is 804,000 miles (1,297,000 kilometers) from Earth and 735,000 miles (1,185,000 kilometers) from the Moon. At this range, both bodies could be captured in the same image. Image credits: NASA/Goddard/University of Arizona.

OSIRIS-REx is a NASA asteroid study-and-sample-return mission. Its goal is to reach and sample an asteroid called 101955 Bennu, and return a sample to Earth by 2023 for detailed analysis. But once again, NASA spoils us with something extra. This time, it’s a composite image of the Earth and the Moon.

Made from data captured by OSIRIS-REx’s MapCam instrument on October 2, 2017, the image was taken at about 3 million miles (5 million kilometers) from Earth, roughly 13 times the distance between the Earth and its Moon. Three images shot at different wavelengths were combined and color-corrected to create the result we see above. The moon was brightened to make it more clearly visible.

However, the image is somewhat deceptive. Although OSIRIS’ angle offers a great view of the two celestial bodies, it isn’t perfect. Specifically, the location of the shuttle was not perpendicular on the Earth-Moon axis, which means that the perspective is a bit skewed. In this case, the obtuse angle is about 142°, which is quite different from the 90° angle which would have created a perfect image.

The angle between the three objects is 142° — 90° would be required for non-distorted perspective.

A good rule of thumb is that you could fit about 30 Earths in the space between our planet and the Moon. But if you’d copy and paste the Earth in NASA’s image, you’d see that you can only fit about 20 Earths in there, meaning you see about two-thirds of the real distance here. Nevertheless, it remains an impressive feat, a vivid visualization of an ungodly distance.

However, this isn’t the only photo of its kind. About one year ago, NASA’s Mars Reconnaissance Orbiter sent back an even broader photo which captured the Earth and Mars in the same frame. You can see the humbling image here.

Credit: University of Oxford / Jon Wade.

Not so dry after all: Mars lost much of its water to the crust

Credit: University of Oxford / Jon Wade.

Credit: University of Oxford / Jon Wade.

Scientists agree that Mars used to have water. Rivers, streams, lakes, even oceans seem to once have dotted the Martian landscape billions of years ago. But then it vanished — how and where it went being open questions among researchers. At least some of it escaped into space, then some more of it may have been boiled after the Red Planet lost its magnetic field. Now, an international team of researchers claims Martian water may have become trapped inside the planet’s mantle.

Not that dry after all — not beneath the surface at least

For their study, the team calculated the volume of water that the minerals comprising Mars’ crust could hold. The model, which computed water’s reaction with the crusts of early Earth and Mars, suggests that the Martian crust can trap twice as much water as Earth’s. Despite being a lot smaller than our planet, Mars’ mantle contains far more iron, which is prone to react with water. What’s more, Earth’s crust is more buoyant and warmer at greater depths than the Martian crust, preventing water from reacting within the mantle.

By running each model forward in time, the findings suggest that approximately 300 meters of surface water on Mars could have been absorbed into its crust and is now locked-up in microscopic mineral structures.

“Our calculations suggest that in excess of 9 percent by volume of the Martian mantle may contain hydrous mineral species as a consequence of surface reactions, compared to about 4 per cent by volume of Earth’s mantle,” the authors wrote in the journal Nature. 

An artist’s impression of what ancient Mars may have looked like, based on geological data. Image by Ittiz / NASA.

An artist’s impression of what ancient Mars may have looked like, based on geological data. Image by Ittiz / NASA.

“People have thought about this question for a long time, but never tested the theory of the water being absorbed as a result of simple rock reactions,” said Jon Wade, a research fellow at the British Natural Environment Research Council at the University of Oxford. “Martian meteorites are chemically reduced compared to the surface rocks, and compositionally look very different. One reason for this, and why Mars lost all of its water, could be in its minerology.”

Besides what was absorbed by the crust, some if not most of Mars’ water must have escaped into space. About 3-4 billion years ago, the red planet boasted a hot climate that could sustain an active hydrological cycle. There were heavy rains, rivers of flowing waters, even vast oceans. All of these require a thick atmosphere, though, which the planet lost once its magnetosphere stopped functioning. With nothing to shelter it from cosmic rays and solar storms, the atmosphere thinned to the point that it’s now roughly 100 times less dense than Earth’s atmosphere.

Artist impression of Mars covered in a primitive ocean. Credit: NASA/GSFC.

Artist impression of Mars covered in a primitive ocean. Credit: NASA/GSFC.

All things considered, it seems like Mars never had a chance to keep liquid water on its surface as many forces converged to dry the planet.

“The public’s infatuation with finding life on Mars stems from the many characteristics both Earth and Mars share,” said study co-lead author Brendan Dyck, a researcher at Simon Fraser University. “Early on, both planets had similar potential to sustain life, but as time evolved, Mars lost its surface water along with its potential to sustain complex multi-cellular life.”

“It would be very difficult to sustain life as we know it on Mars even if surface water existed on the planet for a couple million years. Owing to the long time-scales of evolution, surface water would have to exist for billions of years before the evolution of complex multi-cellular life could take place.”

Artist impression of plumes gushing out of Enceladus' south pole. Credit: NASA.

Enceladus’ hidden ocean is kept warm by porous core

Saturn’s icy moon Enceladus is one of the most promising places in the solar system for extraterrestrial life. Buried under miles and miles of ice lies a warm ocean that stretches across the whole body. Recent observations, like those performed by Cassini before it perished, suggest that geysers emanate from hotspots, capable of warming the ocean long enough for some form of life to appear. Now, in a new study, scientists have come just a tad closer to understanding Enceladus’ dynamics after they found evidence that suggests the moon’s core isn’t rocky but rather porous.

Artist impression of plumes gushing out of Enceladus' south pole. Credit: NASA.

Artist impression of plumes gushing out of Enceladus’ south pole. Credit: NASA.

The resourceful Cassini spacecraft explored Saturn and its moon Enceladus for 13 years. A few months back its mission came to an end and NASA engineers instructed the craft to make a suicide jump into Saturn’s atmosphere. NASA thought it’s best to destroy the craft in a controlled fashion then risk having Cassini crash into Enceladus, contaminating the moon in the process.

When Cassini first arrived in Saturn’s system in 2004, NASA scientists marveled when they learned tall geysers were ejecting material hundreds of miles into space from the south pole. Eventually, scientists learned that there is a huge liquid ocean on the little moon and that the tall plumes are made of water-ice mixed with traces of carbon dioxide, ammonia, methane and other hydrocarbons. We also know that the ocean is convecting, meaning it’s active.

Heated from the core

The geysers erupt from cracks present on the moon’s southern polar region. These cracks are known as “tiger stripes” — parallel depressions that are 100km long and 500m deep. According to temperature readings made by Cassini, the tiger stripes are hotter than the rest of the icy crust. So, what’s the heat source?

Scientists are aware that tidal heating can explain some of the heat on the small moon, which is only 241 km (150 miles) in diameter. However, NASA has calculated that the power required to keep the geysers active is in the order of 5GW — enough to power the city of Chicago — and tidal heating can account for just a fraction of that.

In the new study, researchers at the Université de Nantes, France, have accounted for the missing heat. According to their study published in  Nature Astronomy, Enceladus’ tiny core is not solid but rather porous.

The mushy core takes in water from the ocean, which the French researchers calculated it comprises 20% of the core’s mass. The tidal forces associated with the pore water are now more than sufficient to explain how Enceladus’ heat is generated. The researchers are careful to note that the porous core is not really like a sponge but rather more like sand or gravel.

The team led by  Gael Choblet found heat dissipation from the core is not homogeneous, but rather appears as a series of interlinked, narrow upwellings with temperatures in excess of 363K (85°C). The computer model suggests that the hotspots are mainly concentrated at the south pole, in agreement with actual observations. Since the heat is concentrated on just one side of the moon, it’s natural to have enhanced hydrothermal activity which explains the hydrogen in the plumes.

One interesting finding is that the internal tide produces enough heat to warm Enceladus’ ocean for billions of years to come, with important consequences for the prospect of finding extraterrestrial life there. The moon itself is only a hundred million years old. By the most recent estimates, life here on Earth took about 640 million years to appear so if we’re to take this at reference, Enceladus still has a long way to go. Just as well, life might already be presented since the conditions there could be far more hospitable than the hell early Earth must have looked like.

How Spanish scientists described a solar flare in 1886

This is how a Spanish teenager became one of the first people to ever describe the rare phenomenon.

Drawing by Valderrama of the solar flare he observed on 10 September 1886 on a sunspot (with the penumbra shown with hashed lines and the umbra in black). Credits: Library of the Canary Islands Astrophysics Institute. / Credit: IAC.

“A huge, beautiful sunspot was formed from yesterday to today. It is elongated due to its proximity to the limb … by looking at it carefully I noticed an extraordinary phenomenon on her, on the penumbra to the west of the nucleus, and almost in contact with it, a very bright object was distinguishable producing a shadow clearly visible on the sunspot penumbra. This object had an almost circular shape, and a light beam came out from its eastern part that crossed the sunspot to the south of the nucleus, producing a shadow on the penumbra that was lost in the large mass of faculae surrounding the eastern extreme of the sunspot”.

With these words, Juan Valderrama y Aguilar, a 17-year-old amateur astronomer, described what he witnessed with his small telescope, with an aperture of just 6.6 cm and equipped with a neutral density filter to dim the solar light. He wrote down what he witnessed and even made a drawing (see above) of the flare. He then submitted his observations to the French journal L’Astronomie, which published it.

Amazing real-life image of a solar flare ejected on August 31, 2012 from the Sun's atmosphere, the corona, as seen from the Solar Dynamics Observatory. The flare caused an aurora on Earth on September 3. Credit: NASA/Wikimedia Commons.

Amazing real-life image of a solar flare ejected on August 31, 2012 from the Sun’s atmosphere, the corona, as seen from the Solar Dynamics Observatory. The flare caused an aurora on Earth on September 3. Credit: NASA/Wikimedia Commons.

“The case of Valderrama is very unique, as he was the only person in the world more than a century ago to observe a relatively rare phenomenon: a white-light solar flare. And until now no one had realised”, explains José Manuel Vaquero, a lecturer at the University of Extremadura and co-author of an article about the event, now being published in the journal Solar Physics, to Sinc.

White-light solar flashes are caused by the sun’s acceleration of electrons to speeds greater than half the speed of light. They’re sudden flashes of increased Sun’s brightness, usually observed near its surface. Such solar flares are difficult to study without complex equipment, which is why they were rarely seen until recent years.

Before Valderrama, only two instances have ever been reported. The first was by British astronomer Richard C. Carrington in 1859, and the second by the Italian Pietro Angelo Secchi in 1872. Both reports caused quite a stir in their day, as scientists were wondering if the phenomenon would affect the Earth. Valderrama’s case received much less exposure, and the man himself was not as famous as his counterparts. Vaquero will now publish Valderrama’s first biography.

Journal Reference: J.M. Vaquero, M. Vázquez, J. Sánchez Almeida. “Evidence of a White-Light Flare on 10 September 1886”. Solar Physics 292: 33, 2017. DOI 10.1007/sll207-017-1059-6.

Researchers believe they’ve found a great place for a moonbase — thanks to a volcano

In a new study published in Geophysical Research Letters, Japanese researchers describe what could be the site of a potential moonbase: inside a former lava tube.

Lava tube on Earth, in the Hawaii National Park. Image credits: Hermann Luyken.

All the manned missions that have ever reached the moon have been three days or less — and for good reason. The surface of the Moon is an extremely inhospitable place, with dramatic temperature changes, radiation, and meteorite impacts. If we want to establish a moonbase, we either have to build it, which would be extremely difficult, or we could take advantage of something that nature has already set up for us.

Lava tubes (or lava tunnels) are basically caves formed by flowing lava. Sometimes, lava flowing beneath the surface can solidify and form a hard crust which thickens and forms a roof above the still-flowing lava stream. After all the lava has drained or solidified, you’re left with a natural tunnel which can protect you from the hardships of the surface.

We know that the Moon has had rich volcanic activity as we can see the basaltic plains and astronauts even brought home volcanic rocks. Therefore, it’s very likely that lava tubes also exist. Furthermore, because the Moon has a much lower gravity than the Earth, these tunnels are likely much larger because they’re less inclined to collapse under their own weight. Understanding these features, researchers say, is important for a number of reasons.

These features could be immense. Here, a model of Philadelphia is shown inside a theoretical lunar lava tube. Image credits: Purdue University/David Blair.

“It’s important to know where and how big lunar lava tubes are if we’re ever going to construct a lunar base,” said Junichi Haruyama, a senior researcher at JAXA, Japan’s space agency. “But knowing these things is also important for basic science. We might get new types of rock samples, heat flow data and lunar quake observation data.”

The problem is — how do you find these tunnels? In order to pinpoint them, Haruyama and colleagues first worked with scientists from the GRAIL mission, a NASA effort which created a high-quality gravitational map of the Moon. The gravitational field isn’t uniform across the Moon (or the Earth); density variations beneath the surface lead to positive or negative variations. Since lava tunnels are basically voids beneath the surface, the researchers were looking for mass deficits, sometimes called negative anomalies.

Gravitational map of the Moon, with positive (red) and negative (blue) anomalies. Image credits: GRAIL / NASA.


This was only the first step. After researchers identified these potential areas of interest with GRAIL, they analyzed radar data from the SELENE spacecraft. Whenever you send out a radar wave and it encounters a solid feature (say the surface of the planet), some of its energy is bounced back, and some of it continues through. That continuing energy might encounter an underground geological feature, and bounce off of that too. The radar’s receiver can pick up on all these bounces and get a picture of what’s going on beneath the surface. SELENE wasn’t built to detect lava tubes, but if you can identify a ceiling and a floor with a void between the two, you’re good to go.

With this method, the team identified several promising areas around an area called Marius Hill. These lava tunnels, the study reads, could serve as “pristine environment to conduct scientific examination of the Moon’s composition and potentially serve as secure shelters for humans and instruments.” They’re also spacious enough to host even large cities, data shows.

“They knew about the skylight in the Marius Hills, but they didn’t have any idea how far that underground cavity might have gone,” said Jay Melosh, a GRAIL co-investigator and Distinguished Professor of Earth, Atmospheric and Planetary Sciences at Purdue University. “Our group at Purdue used the gravity data over that area to infer that the opening was part of a larger system. By using this complimentary technique of radar, they were able to figure out how deep and high the cavities are.”

The Marius Hills Skylight, as observed by the Japanese SELENE/Kaguya research team. Image by: NASA/Goddard/Arizona State University.

Clearly, having the shelter of these tunnels could prove extremely valuable for future expeditions. No more radiation, no more unpredicted impacts, and a large area to establish a base and research sites. Of course, before we do that, we probably need to go and see it for ourselves, but the fact that scientists know these features exist and where to look for them is already a big plus.

Journal Reference: T. Kaku et al. Detection of intact lava tubes at Marius Hills on the Moon by SELENE (Kaguya) Lunar Radar Sounder.

You can now use Google Maps to explore other moons and planets

It’s now possible to explore Venus, Mercury, Pluto, and several icy moons from the comfort of your own home.

Credits: Google / NASA.

Working with NASA, Google engineers have rolled out a new feature (see here) where you can navigate between various celestial bodies in our solar system, rotating and zooming as you wish. The project drew inspiration from the Cassini spacecraft, which sent us hundreds of thousands of pictures, offering us an unprecedented view of Jupiter, Saturn, and their moons. Google explained:

“Twenty years ago, the spacecraft Cassini launched from Cape Canaveral on a journey to uncover the secrets of Saturn and its many moons. During its mission, Cassini recorded and sent nearly half a million pictures back to Earth, allowing scientists to reconstruct these distant worlds in unprecedented detail. Now you can visit these places—along with many other planets and moons—in Google Maps right from your computer.”

It can be a bit tricky to navigate since Google hasn’t implemented a search feature, but you can just scroll around and explore the areas on your own. The company notes that it worked with astronomical artist Björn Jónsson to bring the images to life.

Image credits: Google / NASA.

Previously, you could have used Google maps to navigate the Earth, the Moon, Mars, Mercury, as well as the International Space Station. Now, you can also check out Ceres, Io, Europa, Ganymede and Mimas. These are not simply small frozen moons, they are active places rich in features, and some of the likeliest places to host extraterrestrial life (not Io though, that place is crazy).

“Explore the icy plains of Enceladus, where Cassini discovered water beneath the moon’s crust—suggesting signs of life. Peer beneath the thick clouds of Titan to see methane lakes. Inspect the massive crater of Mimas—while it might seem like a sci-fi look-a-like, it is a moon, not a space station”, the Google press release reads.

However, the maps aren’t perfect; a few problems have already been reported with the labeling. Planetary scientist Emily Lakdawalla has already contacted Google in order to fix the problems.

Still, minor bugs aside, it’s an excellent resource to use both educationally and for fun. Just think about it, the first plane flew about a century ago, and now we have high-resolution maps of planets and moon in our solar systems, available for everyone to access. If that’s not a huge technological leap, I don’t know what is.


Evidence keeps pilling up in favor of the mysterious Planet Nine


Illustration of Planet Nine. Credit: NASA/JPL-Caltech/Robert Hurt

A hidden planet almost ten times as massive as Earth might be lingering the in the darkest recesses of the solar system. Scientists haven’t yet spotted this mysterious body, tentatively called Planet Nine, and they’re not even sure it exists. However, indirect evidence suggests Planet Nine is pulling strings throughout the solar system by stretching the orbits of distant bodies and, perhaps, even tilting the plane of the entire solar system on one side.

Super-Earth puppeteer

In early 2016, Konstantin Batygin and Mike Brown, two planetary astrophysicists at the California Institute of Technology (Caltech) in Pasadena, made waves after they predicted an unidentified new planet is chilling somewhere in the outer solar system. Their calculations suggest a number of objects from the Kuiper Belt, the circumstellar disc beyond the known planets, were aligning in a strange way, without any consistent explanation. After many iterations, no model could explain this erratic behavior other than a new planet roughly ten times more massive than Earth and about 20 times farther from the Sun than Neptune. Scientists class a planet the size of Planet Nine as a Super-Earth.

“This would be a real ninth planet,” Brown, who is one of the people responsible for de-classifying Pluto as a planet, said at the time of the controversial announcement. “There have only been two true planets discovered since ancient times, and this would be a third. It’s a pretty substantial chunk of our solar system that’s still out there to be found, which is pretty exciting.”

As wild and unbelievable as all of this may sound at first glance, subsequent studies support this assumption, or at least they don’t contradict it. Now, according to the most recent investigations, it’s actually difficult to imagine the solar system’s mechanics without Planet Nine.

“There are now five different lines of observational evidence pointing to the existence of Planet Nine,” said  Batygin, in a recent statement. “If you were to remove this explanation and imagine Planet Nine does not exist, then you generate more problems than you solve. All of a sudden, you have five different puzzles, and you must come up with five different theories to explain them.”


Caltech professor Mike Brown and assistant professor Konstantin Batygin have been working together to investigate Planet Nine. Credit: Lance Hayashida/Caltech.

There are at least six objects in the Kuiper Belt whose elliptical orbits point in the same direction. They’re also tilted in the same way, about 30 degrees downward compared to the pancake-like plane within which the solar system’s planet orbit the sun. 

Computer simulations suggest there should be more planets showing a ‘weird’ tilt if Planet Nine was truly out there. Moreover, Planet Nine should tilt some objects on the order of 90 degrees, forming an “X” between these objects and the solar system’s plane. Five such objects already fit this description.

Planet Nine could have also tilted the planets of our solar system in the last 4.5 billion years according to another study, which explains why the solar system’s plane is tilted about 6 degrees with respect to the sun’s equator. Over time, this mysterious body could make the entire solar-system plane precess or wobble, just like a top on a table

“Planet Nine may have tilted the other planets over the lifetime of the solar system,” said study lead author Elizabeth Bailey, an astrophysicist and planetary scientist at the California Institute of Technology in Pasadena.

Another study published this week by Juliette Becker, a doctoral student at the University of Michigan, analyzed hundreds of “Trans-Neptunian Objects,” or TNOs — rocky objects smaller than Pluto that orbit the sun at a greater average distance than Neptune. Becker’s investigation suggests that these TNOs are aligned in the orbits they currently occupy because of Planet Nine’s influence.

Lastly, Planet Nine can explain another longstanding puzzle among astrophysicists involving the solar system’s so-called contrarians. These are far-away objects that orbit the cold deeps of the solar system in the opposite direction from everything else in the solar system. Planet Nine’s gravitational influence could be flinging these objects around.

“No other model can explain the weirdness of these high-inclination orbits,” Batygin said. “It turns out that Planet Nine provides a natural avenue for their generation. These things have been twisted out of the solar system plane with help from Planet Nine and then scattered inward by Neptune.”

All that remains is to find this mysterious planet — which may prove to be more difficult than it sounds. For now, scientists are pointing the Subaru Telescope at Mauna Kea Observatory in Hawaii towards different patches of the sky to do just that.

As for how Planet Nine got here in the first place, scientists aren’t sure yet. Batygin says that we shouldn’t bother too much about its origin before we actually find it, but didn’t stop some astronomers from proposing some hypotheses. A 2016 paper published in the Monthly Notices Letters of the Royal Astronomical Society, claims Planet 9 or Planet X, as it’s sometimes called, might actually be an exoplanet, initially formed in another solar system but captured by our sun in an interstellar gravity tug of war.

It’s quite amazing, though, that we’re discussing the search for a new planet in our solar system after so many years since the last one was confirmed.

NASA observatory highlights the importance of studying CO2 on Earth: it’s connected to everything

NASA’s high-resolution satellites are offering us a unique view of what’s happening with carbon dioxide on Earth

Aside from looking up towards the stars, NASA’s eyes are also glancing down on Earth. From its vantage point, the Orbiting Carbon Observatory-2 (OCO) sees the subtle strings that link CO2 to everything on the planet. The ocean, all the land, the atmosphere, all ecosystems and creatures and last but certainly not least — mankind. A special collection of five research papers document how CO2 is intertwined with all aspects of life on Earth.

Every year, mankind emits a whopping 40 billion tons of CO2. Most of that, the data shows, comes from cities. More than 70 percent of carbon dioxide emissions from human activities originate in urban areas, but it’s hard to see just what happens to the CO2 because it merges with the atmosphere right after it’s emitted. In order to better understand these processes, Florian Schwandner of JPL and colleagues used OCO-2 data to study changes in the CO2 within the air column below the satellite. For instance, within the city of Los Angeles, researchers were able to isolate some individual sources of CO2 and then track the carbon as it moved from the urban center to the suburbs and then towards the outskirts of the city.

OCO-2’s orbit also enabled scientists to monitor CO2 emissions from some volcanoes — which contrary to popular belief, are very small compared to mankind’s contribution. Atmospheric carbon dioxide acts as Earth’s thermostat, and we’re the ones supercharging it — not nature.

Carbon-monitoring satellites are extremely useful as they allow us to get a broader and more accurate picture of what’s happening to the greenhouse gas within our atmosphere, but the problem is that they’re few and far between.

“They’re very precise, but there’s very few of them,” says Annmarie Eldering, an environmental engineer at NASA’s Jet Propulsion Laboratory. “If you want to understand how the continent of Africa or the Pacific Ocean relate to the global carbon cycle, that data set isn’t very sensitive.”

Building up a picture of CO2 is a complex business that requires a lot of modelling. Image credits: NASA / JPL.

The second paper analyzed how the 2015-16 El Niño affected the carbon dioxide cycle over the Pacific. El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns, typically associated with a large band of hotter water. The 2015-16 event was the hottest in human history, and it dramatically raised CO2 emissions over large areas of the globe. However, human emissions remained largely similar, so what gives?

Aside from carbon dioxide, OCO’s instruments also allowed it to observe solar-induced fluorescence, or SIF. The SIF is emitted by chlorophyll molecules in plants, indicating that photosynthesis is happening. This was the key to the extra CO2. In South America, the biggest drought in three decades limited the vegetation’s ability to consume CO2. In Africa, high temperatures helped decompose plant material, which also releases CO2; and in Asia, rampant fires released massive quantities of peat carbon which had accumulated over thousands of years.

“This is the gold star for OCO: we wanted to understand what happened in different regions of the world, Annmarie Eldering adds.

The last El Nino in 2015-16 impacted the amount of carbon dioxide that Earth’s tropical regions released into the atmosphere, leading to Earth’s recent record spike in atmospheric carbon dioxide. The effects of the El Nino were different in each region.Credit: NASA-JPL/Caltech.

These observations are truly groundbreaking — the fact that they were all released at once makes it even more impressive. Talking to BBC, Paul Palmer, an atmospheric scientist at Edinburgh University in the UK, says that this type of satellites opens up an entirely new way of looking at our planet.

“This is the first major climate variation where we’ve had satellite observations of atmospheric composition, and of land properties and of ocean properties – all at the same time,” he said.

“The last major El Niño was 1997/8 and that was really just the start of the satellite tropospheric chemistry missions. We’re now sampling a lot of different variables and the real breakthrough comes when you tie all the information together. We’re not quite there yet, but this is a really good start.”

The work also involved heavy use of complex modeling, and these results will help finesse future models even more.

“Understanding how the carbon cycle in these regions responded to El Nino will enable scientists to improve carbon cycle models, which should lead to improved predictions of how our planet may respond to similar conditions in the future,” said OCO-2 Deputy Project Scientist Annmarie Eldering of JPL. “The team’s findings imply that if future climate brings more or longer droughts, as the last El Nino did, more carbon dioxide may remain in the atmosphere, leading to a tendency to further warm Earth.”

However, the Trump administration has slashed the budget for such projects and has announced plans to do so even more in the future. In their attempt to promote fossil fuels, America’s leaders are taking away some of the most vital tools scientists are using to study the planet.

For more information on NASA’s Orbiting Carbon Observatory-2 mission, visit NASA’s OCO page.

Gravity map reveals Martian crust might be lighter than we thought

This could help us better understand the Red Planet and its evolution.

A gravity map of Mars. Martian gravity can reveal a lot of the planet’s secrets, especially those of its crust. Credits: NASA/Goddard/UMBC/MIT/E. Mazarico.

Gravity on our planet isn’t uniform at all. Sure, it might seem that way to our human senses, but there are lots of variations, depending on the Earth’s subsurface and variations in its shape. For instance, denser rocks will lead to a slightly stronger gravitational field, whereas those with pores or voids lead to a weaker local field.

We’ve long created general gravity maps of the Earth and even localized, detailed maps. Even the Moon has been charted in detail, using NASA’s GRAIL mission, which sent two space probes to study the field. Since gravity decreases with distance, things closer to the surface have a stronger impact than things deeper in the underground, and now we have a significantly better understanding of the Moon’s crust (which has a more pronounced effect on the gravity field).

In fact, crustal density and gravity have many things in common — we can derive one from the other, through a sophisticated mathematical process called inversion. Map the gravitational field, and you’ll learn a lot about the density — you could even build a density model, as we’ve done for Earth. But using the same approach with Mars would be difficult because we just don’t have enough data, so NASA had to try a different strategy.

They used what little gravitational information we have about Mars, relying on what little we learned directly about the Martian surface and even more on the topography of the planet. They learned that Mars has a lighter crust than what was expected, based on what we know of the rocks’ composition. Researchers were expecting rocks about as dense as the oceanic crust here on Earth, but they came up with less than that.

“As this story comes together, we’re coming to the conclusion that it’s not enough just to know the composition of the rocks,” Greg Neumann, a researcher on the project, said in a statement. “We also need to know how the rocks have been reworked over time.”

The final density figure is 2,582 kilograms per meter cubed (about 161 pounds per cubic foot). That’s comparable to the average density of the lunar crust and significantly less than Earth’s oceanic crust, which is about 2,900 kilograms per meter cubed (about 181 pounds per cubic foot). This seems to indicate that the main culprit for this difference, the crust, is more porous than we initially thought.

“The crust is the end-result of everything that happened during a planet’s history, so a lower density could have important implications about Mars’ formation and evolution,” said Sander Goossens of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Goossens is the lead author of a Geophysical Research Letters paper describing the work.

Before publishing these results, they tested their method using data from the GRAIL mission and came up with accurate results. They also correlated positive anomalies (stronger gravitational field) to known volcanoes, something which was expected. But the approach they used doesn’t have a good resolution, so we’ll have to wait for more data to confirm these findings.

The researchers also note that NASA’s InSight mission — short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — will carry out the measurements which could confirm their finding. This Discovery Program mission, scheduled for launch in 2018, will place a geophysical lander on Mars to study its deep interior.

You can study the model and even download on this page from NASA’s website.

Journal Reference: Sander Goossens, Terence J. Sabaka, Antonio Genova, Erwan Mazarico, Joseph B. Nicholas, Gregory A. Neumann. Evidence for a low bulk crustal density for Mars from gravity and topography. DOI: 10.1002/2017GL074172

Credit: YouTube capture.

NASA will fly jets to chase the upcoming total eclipse to learn more about the sun

Credit: YouTube capture.

Credit: YouTube capture.

The upcoming August total eclipse has gotten millions of American hyped over what can be described as a once in a lifetime event. Having witnessed a total eclipse, albeit once and when I was very young, I can testify to its unique beauty. Being in the business of space, NASA is also obviously interested in this occurrence. But while most of us will study the eclipse from behind some $2 cardboard shaded glasses, NASA, in its inconspicuous style, will fly multiple jets right though the eclipse line effectively chasing the moon’s shadow.

Secrets in the dark

Pilots will fly WB-57F jets which were first deployed in 1953 as reconnaissance aircraft. They’ve been heavily upgraded since, though, featuring modern avionics but also sophisticated imaging instruments fitted on the nosecone. The telescope cameras can see in infrared and can capture photos and videos at high resolution.

The main target is the sun’s atmosphere, particularly its corona which due to some odd reasons measures millions of degrees Celsius while the surface itself has a temperature of only about 6,000 degrees Celsius.

No one is sure why this happens but there are some hypotheses. One suggests that a special type of magnetic waves called Alfvén waves might dissipate energy into the sun’s outer atmosphere. Another hypothesis points the finger at nanoflares — micro explosions on the surface of the sun — that are too small to detect individually but collectively occur frequently throughout the surface of the sun providing a source of heat that could funnel the corona.

The eclipse’s cover provides an extremely rare opportunity for the instruments fitted on the aircraft to study this weird phenomenon. NASA is also interested in imaging the planet Mercury which will become far more visible during the eclipse.

“These could well turn out to be the best ever observations of high frequency phenomena in the corona,” says Dan Seaton, co-investigator of the project and researcher at the University of Colorado in Boulder, Colorado. “Extending the observing time and going to very high altitude might allow us to see a few events or track waves that would be essentially invisible in just two minutes of observations from the ground.”

The two WB-57F jets will launch from Ellington Field near NASA’s Johnson Space Center in Houston on Aug. 21, 2017. They’ll fly at an altitude of 50,000 feet where the sky is 20 to 30 times darker than it is from the ground providing excellent imaging conditions. But while it’s tempting to think these two planes will chase the eclipse throughout its development over the States, the reality is they’re far too slow. Even at their top speed of 600 mph, the jets can only stay behind the moon’s shadow for so long which moves at 2,400 mph. To be more precise, each plane will observe the total eclipse for about three and a half minutes each as they fly over Missouri, Illinois and Tennessee.