Tag Archives: planets

An artist’s view of the TRAPPIST-1 system. The TRAPPIST-1 star is home to the largest batch of roughly Earth-size planets ever found outside our solar system. An international study involving researchers from the Universities of Bern, Geneva and Zurich now shows that the exoplanets have remarkably similar densities, which provides clues about their composition (NASA/JPL-Caltech)

The Trappist-1 exoplanets could be worlds of water or rust

The star system of Trappist-1 is home to the largest group of Earth-like planets ever discovered elsewhere in the Universe by astronomers. This means that investigating these seven rocky worlds gives us a good idea of how common exoplanets with similar compositions to our own are in the Milky Way and the wider cosmos.

New research has revealed that these planets, which orbit the Trappist-1 star 40 light-years away from Earth, all have remarkably similar compositions and densities. Yet, all are less dense than Earth.

The results could indicate these are worlds with much more water than is found on earth, or possibly even that these planets are composed almost entirely of rust.

An artist’s view of the TRAPPIST-1 system. The TRAPPIST-1 star is home to the largest batch of roughly Earth-size planets ever found outside our solar system. An international study involving researchers from the Universities of Bern, Geneva and Zurich now shows that the exoplanets have remarkably similar densities, which provides clues about their composition (NASA/JPL-Caltech)
An artist’s view of the TRAPPIST-1 system. The TRAPPIST-1 star is home to the largest batch of roughly Earth-size planets ever found outside our solar system. An international study involving researchers from the Universities of Bern, Geneva and Zurich now shows that the exoplanets have remarkably similar densities, which provides clues about their composition (NASA/JPL-Caltech)


This similarity between the exoplanets makes the Trappist-1 system significantly different from our own solar system which consists of planets with radically compositions and densities. Trappist-1’s worlds are dense, meaning they are like the rocky planets in our solar system, Earth, Mars, Venus, and Mercury. The system seems to be lacking larger gas dominated planets like Jupiter, Saturn, Uranus and Neptune.

The finding, documented in a paper published in the Planetary science Journal shows how the system, first discovered in 2016, offers insight into the wide variety of planetary systems that could fill the Universe.

This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii, masses, densities and surface gravity as compared to those of Earth. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. (NASA/ JPL - Caltech)
This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii, masses, densities and surface gravity as compared to those of Earth. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. (NASA/ JPL – Caltech)

“The new observations allowed us to use transit data from a much longer time span than was available to us for the 2018 calculations,” explains Simon Grimm of the University of Bern, who as well as being involved in the current study, was part of a 2018 team that provided the most accurate calculation of the masses of the seven planets thus far. “With the new data, we were able to refine the mass and density determinations of all seven planets.

“It turned out that the derived densities of the planets are even more similar than we had previously expected.”

Seven Exoplanets with Similar Densities

The similarity in densities observed in the Trappist-1 exoplanets seen by the astronomers hailing from the Universities of Bern, Geneva and Zurich, indicates that there is a good chance they are composed of the same materials at similar ratios.

These are the same materials that we believe form most terrestrial planets, iron, oxygen, magnesium, and silicon. But there is a significant difference between our terrestrial world and the Trappist-1 exoplanets.

Comparison of TRAPPIST-1 to the Solar System: A planet's density is determined by its composition, but also by its size: Gravity compresses the material a planet is made of, increasing the planet's density. Uncompressed density adjusts for the effect of gravity, and can reveal how the composition of various planets compare. (NASA/JPL-Caltech 4)
Comparison of TRAPPIST-1 to the Solar System: A planet’s density is determined by its composition, but also by its size: Gravity compresses the material a planet is made of, increasing the planet’s density. Uncompressed density adjusts for the effect of gravity, and can reveal how the composition of various planets compare. (NASA/JPL-Caltech )

The planets in the Trappist-1 system appear to be about 8% less dense than the Earth. This suggests that the materials that comprise them exist in different ratios than they do throughout our home planet.

This difference in density could be the result of several different factors.

One of the possibilities being investigated by the team is that the surfaces of the Trappist-1 exoplanets could be covered with water, reducing their overall density. Combining the planetary interior models with the planetary atmosphere models, the team was able to evaluate the water content of the seven TRAPPIST-1 planets with what Martin Turbet, an astrophysicist at the University of Geneva and co-author of the study describes as “a precision literally unprecedented for this category of planets.”

For the Trappist-1 system’s four outermost planets, should water account for the difference in density, the team has estimated that water would account for 5% of their overall masses. This is considerably more than the 0.1% of Earth’s total mass made up of water.

Rust Nevers Sleeps for the Trappist-1 Planets

Another possibility that could explain why the Trappist-1 exoplanets have lower densities than Earth is the fact that they could be composed of less iron than our planet is–21% rather than the 32% found in the Earth.

It’s also possible that the iron within the seven exoplanets could be bonded with oxygen forming iron oxides–commonly known as rust. This additional oxygen would reduce the planet’s densities.

Shown here are three possible interiors of the TRAPPIST-1 exoplanets. The more precisely scientists know the density of a planet, the more they can narrow down the range of possible interiors for that planet. All seven planets have very similar densities, so they likely have a similar compositions (NASA/ JPL - Caltech)
Shown here are three possible interiors of the TRAPPIST-1 exoplanets. The more precisely scientists know the density of a planet, the more they can narrow down the range of possible interiors for that planet. All seven planets have very similar densities, so they likely have a similar composition (NASA/ JPL – Caltech)

Iron oxides give Mars its rust-red colour, but they are pretty much confined to its surface. Its core is comprised of non-oxidized iron like the solar system’s other terrestrial planets. If iron-oxide accounts for the seven exoplanet’s lower densities it implies that these worlds are rusty throughout and lacking solid non-oxidized iron cores.

“The lower density might be caused by a combination of the two scenarios – less iron overall than and some oxidized iron,” explains Eric Angol, an astrophysicist at the University of Washington and lead author of the new study. “They might contain less iron than Earth and some oxidized iron like Mars.”

Angol also points out that the Trappist-1 planets are likely to have a low-water content, an idea supported by previous research. “Our internal and atmospheric structure models show that the three inner planets of the TRAPPIST-1 system are likely to be waterless and that the four outer planets have no more than a few per cent water, possibly in liquid form, on their surfaces,” says Turbet.

This seems to favour the theory that the lower density of the Trappist-1 planets is a result of one or both of the iron scenarios suggested by the researchers.

There’s Still a Lot to Learn from Trappist-1


Since its discovery in 2o16, the Trappist system has been the subject of a wealth of observations made by both space and ground-based telescopes alike. Before it was decommissioned at the start of January 2020 the team used the Spitzer Space Telescope to collect their data. This telescope, operated by NASA’s Jet Propulsion Laboratory, alone has clocked in more than 1,000 hours of targeted observations of the exoplanets.

This new study demonstrated the importance of studying systems such as Trappist-1 for extended periods of time.

Caroline Dorn, an astrophysicist at the University of Zurich also highlights the fact that studying systems like this could answer questions about the habitability of exoplanets and the possibility of life elsewhere in the Universe.

“The TRAPPIST-1 system is fascinating because around this one star we can learn about the diversity of rocky planets within a single system,” concludes Dorn. “And we can actually learn more about an individual planet by studying its neighbours as well, so this system is perfect for that.”

“The night sky is full of planets, and it’s only been within the last 30 years that we’ve been able to start unravelling their mysteries, also for determining the habitability of these planets.”

Original Research

Agol. E., Dorn. C., Grimm. S. L., et al, ‘Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides,’ Planetary Science Journal, [https://arxiv.org/abs/2010.01074]

Northwest Africa (NWA) 11119 is the oldest igneous meteorite recorded. Credit: University of New Mexico.

Unique 4.6-billion-year-old meteorite is a remnant of the early solar system

A never-before-seen space rock — older than Earth itself! — stands out among the 40,000 meteorites researchers have recovered so far. Scientists claim this is the oldest igneous meteorite found thus far and by studying it they hope to learn more about how the solar system formed and evolved.

Northwest Africa (NWA) 11119 is the oldest igneous meteorite recorded. Credit: University of New Mexico.

Northwest Africa (NWA) 11119 is the oldest igneous meteorite recorded. Credit: University of New Mexico.

About 4.6 billion years ago, a massive cloud of gas and dust collapsed under its own gravity, forming a spinning disk with a proto-sun at its center. Under the influence of gravity, material accreted into small chunks that got larger and larger, forming planetesimals. Many such objects likely broke back apart as they collided with each other, but others would have coalesced — eventually becoming planets and moons. However, the journey to building a planet was quite messy. One study published in Nature concluded that Earth lost nearly 40 percent of its mass as vapor during collisional growth.

The weird meteorite described by Carl Agee, the Director of the University of New Mexico’s Institute of Meteoritics, and colleagues provides chemical evidence that silica-rich crustal rocks were forming on planetesimals at least 10 million years before the assembly of the terrestrial planets.

At first, however, the space rock looked pretty unassuming. The researchers initially thought that the rock — called Northwest Africa 11119, as it was discovered in the sand dunes of Mauritania — was terrestrial in origin due to its light appearance and silica-rich content.

The rock, which was originally found by a nomad and later sourced by Agee via a meteorite dealer, was handed over to graduate student and lead author Poorna Srinivasan to study its mineralogy. Using an electron microprobe and a CT (computed tomography), Srinivasan started noticing unusual details in NWA 11119 and concluded it is extraterrestrial in origin, judging from its oxygen isotopes. What’s more, the silica-rich achondrite meteorite contains information involving the range of volcanic rock compositions (their ‘recipes’) within the first 3.5 million years of solar system creation.

“The age of this meteorite is the oldest, igneous meteorite ever recorded,” Agee said in a statement. “Not only is this just an extremely unusual rock type, it’s telling us that not all asteroids look the same. Some of them look almost like the crust of the Earth because they’re so light colored and full of SiO2. These not only exist, but it occurred during one of the very first volcanic events to take place in the solar system.”

Artist impression of NWA) 11119, seen in right bottom corner. Credit: University of New Mexico.

Artist impression of NWA) 11119, seen in right bottom corner. Credit: University of New Mexico.

According to Srinivasan, the mineralogy of the rock is unlike anything the researchers have worked on before. One of its most striking characteristics is that large silica crystals of tridymite — which are similar to quartz — comprise about 30 percent of the total meteorite. This kind of composition is unheard of in meteorites — which typically have ‘basaltic’ compositions with much lower abundances of silica — and can only be found in certain volcanic rocks from Earth.

Subsequent investigations using inductively coupled plasma mass spectrometry determined the precise formation age of the meteorite: 4.565 billion years.

But where exactly NWA 11119 formed is still a mystery.

“Based on oxygen isotopes, we know it’s from an extraterrestrial source somewhere in the solar system, but we can’t actually pinpoint it to a known body that has been viewed with a telescope,” said Srinivasan. “However, through the measured isotopic values, we were able to possibly link it to two other unusual meteorites (Northwest Africa 7235 and Almahata Sitta) suggesting that they all are from the same parent body – perhaps a large, geologically complex body that formed in the early solar system.”

It’s possible that this larger parent body was torn to pieces through the collision with some other asteroid or planetesimal, ejecting fragments that would eventually hit Earth at a yet unknown time in the past.

“The meteorite studied is unlike any other known meteorite,” says co-author and ASU School of Earth and Space Exploration graduate student Daniel Dunlap. “It has the highest abundance of silica and the most ancient age (4.565 billion years old) of any known igneous meteorite. Meteorites like this were the precursors to planet formation and represent a critical step in the evolution of rocky bodies in our solar system.”

The findings published in the journal Nature Communications are important because they help scientists piece together how the building blocks of planets formed in the early solar system. Specifically, this “missing part of the puzzle that we’ve now found that tells us these igneous processes act like little blast furnaces that are melting rock and processing all of the solar system solids,” Agee said.

“Ultimately, this is how planets are forged,” he added.

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.

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.

Super Venus/Earth.

Conditions on early-Venus might have allowed for an ocean of liquid water

Long ago, Venus might have harbored an entire ocean.

Super Venus/Earth.

Artist’s concept of a Super Venus (left) and a Super Earth (right).
Image credits NASA / JPL-Caltech

A team of researchers led by Université de Versailles Saint-Quentin-en-Yvelines (Guyancourt, France) planetary scientist Emmanuel Marcq believe it’s very likely early Venus had an ocean.

Their theory is based on a number of computer simulations the team ran to understand how the molten crust of young rocky planets interacts with their burgeoning atmospheres and incoming energy from parent stars. These simulations showed that if an early-Venus-like planet had carbon dioxide levels similar to those seen today, it would only need about 10% of Earth’s water volume to form a stable planetary ocean. If you tweak some of the planet’s characteristics — like cloud reflectiveness, for example — to get the least ocean-conductive environment possible, you’d still need just 30% of Earth’s water to form a stable ocean.

Whether or not a planet can maintain liquid water on its surface mainly comes down to it keeping within a specific range of temperatures and pressures. Both of these are the result of how much energy a planet gets from its parent star versus how much it can dump back into space — which in turn can be boiled down to the complex interplay between the atmosphere’s chemistry, the reflectivity of its clouds, and other factors such as distance from the star.

Marcq’s team’s findings build on the results of a paper published last year, which found that Venus’ slow rotation speed could have allowed for a continuous, sufficiently-thick cloud cover to form and keep average temperatures around 15° Celsius as recently as 715 million years ago. That’s a very far cry from present Venus’ crisp average of 460° C, but more importantly, it’s cold enough to allow for a shallow ocean to form.

So the fact that Venus could harbor an ocean isn’t that surprising, Marcq says. But it’s still “very much a hotly debated, open question” if Venus did harbor an ocean. The team’s work comes to prop up the theory that it did, as their results suggest it was much more likely for water vapor to condense into an ocean during Venus’ early days than previously believed.

However, their simulations don’t offer any insight into how later changes on Venus would’ve impacted this ocean — if there was an ocean at all. It also doesn’t offer any answers as to how long this grace period lasted on Venus, or where the ocean went afterward to create the decidedly-dry neighbor we have today. So far from settling the debate, the results are likely to fan the flames even further.

But on the plus side, the simulations can help planetary scientists refine their search for habitable planets outside of the solar system by offering a better idea of what conditions in a planet’s atmosphere and on the ground level are likely to make it suitable for life.

The paper “The relative influence of H2O and CO2 on the primitive surface conditions and evolution of rocky planets” has been published in The Journal of Geophysical Research: Planets.

Twitterers compete with suggestions for newly discovered exoplanets’ names — hilarity ensues

Remember the Boaty McBoatface incident? Well, the Internet is trying its digital hand at naming things again, and this time it’s for NASA’s latest exciting discovery: the 7 new exoplanets of the Trappist system. Twitter users have come up with a wonderful mix of suggestions ranging from trollish or tongue-in-cheek, all the way to some that might actually have some merit as potential names for the planets.

Image credits NASA.

The Internet doesn’t have the best track record when it comes to naming things. Just last March, UK’s Natural Environment Research Council (NERC) invited people to vote on what name their newest arctic research vessel should be christened with. NERC went with RRS Sir David Attenborough in recognition to the world famous UK naturalist and broadcaster — but that’s not what the public voted for. Oh no.

After former BBC Radio Jersey presenter James Hand jokingly suggested the council should go with Boaty McBoatface, the suggestion picked up a huge number of votes, quickly becoming the most popular name. Thankfully for the NERC, they announced from the beginning that the poll was non-binding in nature so they could opt for what they considered a “more appropriate” name.

Just last month,  NASA announced the discovery of seven exoplanets in the Trappist system, three of which lie in the Goldilocks zone of potential habitability. Currently named Trappist-1b to h, the planets’ permanent nomenclature will be decided by the International Astronomical Union — but the opportunity to name them was too good for the collective creativity of the Internet to pass up on, and people are tweeting their ideas under the hashtag 7NamesFor7NewPlanets. Some suggestions are simply funny, we’ve seen some nods to cultural references, and some names that actually sound pretty good. And surely enough, “Planet McPlanetface” made it in the suggestions.

Here are some of the highlights, starting with the funnies.

Lost it at Wanda.

https://twitter.com/trutherbotred/status/835341145483849729

Rumors say the new planets will have universal docking ports. We’ll have to wait and see. And, talking about planets that NASA says aren’t ‘really’ planets:

There’s also a lot of cultural referencing going on, with the names of great houses from Game of Thrones being suggested, the dwarfs’ names in Snow White, as well as nods to the Harry Potter books. But this one I enjoyed the most:

https://twitter.com/Edamessiah/status/835880897756950530

Some users have also pointed out the connection to Belgian beers of the same name, suggesting the planets be named after the Trappist breweries.

https://twitter.com/pepelero/status/837246012586610688

There’s also some activism going on under the hashtag:

And this one, which probably best captures the gist of how half the US feels about the next 4 years.

Some users view the christenings as an opportunity to those who have sacrificed in humanity’s efforts to reach for the stars — several tweets call for the planets to be named for the seven astronauts who lost their lives aboard the Challenger in 1986.

So will these suggestions actually make it on the star charts? Probably not.

“The TRAPPIST #7NamesFor7NewPlanets was a trending hashtag that was started by Twitter users, and we were simply joining an existing conversation by posting the current scientific names with the hashtag. We are not collecting suggestions, and we rely on the IAU’s process for the naming of these planets,” NASA’s Social Media Manager John Yembrick told me in an e-mail.

Seeing the generally light-hearted and humorous way these names are being suggested on Twitter, it’s unlikely that the IAU will actually go with any of them. But there are some good contenders tweeted under the hashtag, so the union may still surprise us in the end. Which means there’s still a tiny hope for Pluto.

Author’s note: Corrected the article after receiving NASA’s Social Media Manager John Yembrick’s email. Initially, it stated NASA started the hashtag to ask for suggestions for the new names; 1:50 am EET.

Venus could once have been a very welcoming planet, NASA study found

Our closest neighboring planet, Venus, is not a place you’d like to visit. Scorching surface temperatures, an atmosphere so dense it would crush your bones, and acid thunderstorms. It’s about as far from a life-friendly planet as you could get. But, a NASA research team proposes that Venus’ hellish surface used to be very comfortable and pristine — up until some 700 million years ago.

Image credits Mattias Malmer/NASA/JPL.

“Both planets probably enjoyed warm liquid water oceans in contact with rock and with organic molecules undergoing chemical evolution in those oceans,” David Grinspoon at the Planetary Science Institute in Tucson, Arizona told Aviva Rutkin at New Scientist.

“As far as we understand at present, those are the requirements for the origin of life.”

Venus has all the makings of a planet that should sustain life: it’s very similar in size, density, and chemical composition to our own planet. Its proximity to Earth further suggests that the two planets were formed from the same primordial materials.

“Venus also has an unusually high ratio of deuterium to hydrogen atoms, a sign that it once housed a substantial amount of water, mysteriously lost over time,” says Rutkin.

But at surface level, the two planets couldn’t be more different. Venus is the hottest planet in the Solar System, so hot in fact that rainfall on the planet evaporates before reaching the ground. This is probably for the best as it rains sulphuric acid, not water, on Venus. Its lightning-and-greenhouse-gas-choked atmosphere is dense enough that carbon dioxide becomes liquid at ground level, so potential human visitors would have a very pressing need for protection.

Still, researchers believe that Venus wasn’t always the hellish place we see today. A recent NASA study lends weight to this theory, showing that up to 3 billion years ago the planet could have had mild, Earth-like temperatures and bodies of water.

Michael Way and his team from the NASA Goddard Institute for Space Studies simulated four versions of early Venus, each with slightly altered factors — such as length of days, incoming energy from the Sun, etc. Left to cook for a few billions of years, the most promising model evolved to have moderate surface temperatures, dense cloud cover to protect the surface from solar radiation, even snow. This model produces habitable conditions in 2-billion-year stretches and estimates that the planet remained habitable up to 715 million years ago.

One catch is that for the model to work, it requires Venus to have been spinning as slowly as it does today – something that researchers have yet to prove. We know that Earth’s rotation has been steadily slowing down over time, and some researchers argue that the same could be true for Venus.

“If Venus was spinning more rapidly, all bets are off,” said Michael Way.

“But, under the right conditions, “You get temperatures almost like Earth. That’s remarkable.”

If the models are accurate, however, the implications could be huge — a few billion years is more than enough time for life to have evolved on Venus during its milder days. Unfortunately, the Venus of today doesn’t really lend well to searching for clues of long-lost life. And we don’t know why it got this way, we don’t know what or when went wrong.

“It’s one of the big mysteries about Venus. How did it get so different from Earth when it seems likely to have started so similarly? The question becomes richer when you consider astrobiology, the possibility that Venus and Earth were very similar during the time of the origin of life on Earth,” Grinspoon said.

The only way to find out if Venus was ever habitable, if life ever evolved here, to figure out what happened for it to end up as it is, is to go there and poke around — something that NASA is already considering.

The full paper, “Was Venus the First Habitable World of our Solar System?” has been accepted for publication in Geophysical Research Letters.

NASA’s Kepler Space Telescope discovers 104 new planets outside of Milky Way

Using data from NASA’s Kepler Space Telescope during the K2 mission in combination with observations from various Earth-based telescopes, an international team of astronomers has discovered 104 new exoplanets, four of which could hold the potential for life.

An illustration of NASA's Kepler Space Telescope during the K2 mission. Credit: NASA/JPL-Caltech

An illustration of NASA’s Kepler Space Telescope during the K2 mission. Credit: NASA/JPL-Caltech

Prior to the K2 mission, the Kepler focused specifically on measuring the frequency with which planets with sizes and temperatures similar to the Earth occurred around sun-like stars. Now, it focuses on cooler and smaller red dwarf-type stars, which are much more common in the Milky way than sun-like stars.

The new mission also focuses on both the northern and southern hemispheres, as opposed to the initial mission, which was limited to examining a specific portion of the sky in the northern hemisphere.

“Kepler’s original mission observed a small patch of sky as it was designed to conduct a demographic survey of the different types of planets,” said Ian Crossfield of the University of Arizona’s Lunar and Planetary Laboratory and leader of the research. “This approach effectively meant that relatively few of the brightest, closest red dwarfs were included in Kepler’s survey. The K2 mission allows us to increase the number of small, red stars by a factor of 20 for further study.”

Of the 104 new exoplanets discovered outside of our solar system, four are of particular interest due to their potential similarities to Earth. The set of planets are between 20 to 50 percent larger than Earth and orbit a star less than half the size of the sun. In addition, two of them are believed to experience radiation levels from their star that are comparable to those experienced by the Earth.

Although the orbits of the new set of planets are fairly tight, Crossfield believes that the current data suggests that we must consider the possibility of life on such planets until further research says otherwise

“Because these smaller stars are so common in the Milky Way, it could be that life occurs much more frequently on planets orbiting cool, red stars rather than planets around stars like our sun,” he said.

The findings were published in The Astrophysical Journal Supplement Series.

New class of star-stripped super-Earths discovered

Astrophysicists have discovered a new class of exoplanets whose atmospheres and volatile elements have been blown away by the star they’re orbiting. Their findings help cover a previously uncharted gap in planetary populations and offers valuable insight for locating new worlds to colonize.

Too close for comfort.
Image credits: ESO/ .Calcada

There’s an old Latin saying along the lines of “dosage makes the poison,” and that holds true even on immense scales. Planets are on the receiving end of a huge amount of energy emitted by their host star as heat, radiation and charged particles — commonly known as solar winds. Earth sits comfortably in the Goldilocks zone, close enough to the sun so it won’t freeze over but not too close, so it doesn’t bake and burn. It’s also far enough from the sun to allow its magnetic field to effectively repel much of these particles and radiation. But not all earth-like planets are so fortunate.

By using data from NASA’s Kepler space telescope, astrophysicists from the University of Birmingham have discovered a new class of ‘stripped’ rocky planets. These Earth-like planets orbit very close to their stars, and are subjected to a torrent of high-energy radiation and extreme temperatures. Over time, this heat causes the volatile substances in the rocks to escape into the atmosphere. Radiation, in turn, strips the outer gaseous layer, leaving only a shrunk rocky core exposed.

‘For these planets it is like standing next to a hairdryer turned up to its hottest setting,” said Dr Guy Davies, from the University of Birmingham’s School of Physics and Astronomy. “There has been much theoretical speculation that such planets might be stripped of their atmospheres. We now have the observational evidence to confirm this, which removes any lingering doubts over the theory.’

The team used asteroseismology to characterize the stars and their planets they were investigating much more accurately than ever before. Asteroseismology uses the natural resonances of stars to reveal their properties and inner structures.

The findings are important in helping us understand how stellar systems evolve over time. It also highlights the crucial role the host star plays in shaping the planets orbiting it.

Dr Davies added: ‘Our results show that planets of a certain size that lie close to their stars are likely to have been much larger at the beginning of their lives. Those planets will have looked very different,’ Dr Davies added.

The full paper, titled “Hot super-Earths striped by their host stars” has been published online in the journal Nature Communications and can be read here.

The eight planets of our solar system and one dwarf planet shown approximately to scale. Image: Lunar and Planetary Institute

Eight planets and a dwarf in one

Planetary Suite by Steve Guildea; Oil on Canvas, 9 Panels 6'x13'3" (Collection of Merrimack College)

Planetary Suite by Steve Guildea; Oil on Canvas, 9 Panels 6’x13’3″
(Collection of Merrimack College)

This magnificent painting by Steve Gildea combines the planets of our solar system in one beautiful planetary mosaic. It’s a celebration of the geological diversity our solar system possess, illustrating each planet’s surface in the order they orbit the sun, starting from the battered Mercury to lonely Pluto. Speaking of which, Pluto is of course no longer classed as a planet – it’s technically a dwarf planet, but Gildea couldn’t have known this in 1990 when he first revealed the piece.

Of course, the painting was made to hold each planet in proportion. The image below shows how each planet differs in size from one another.

The eight planets of our solar system and one dwarf planet shown approximately to scale. Image:  Lunar and Planetary Institute

The eight planets of our solar system and one dwarf planet shown approximately to scale. Image: Lunar and Planetary Institute

  • Jupiter (69,911 km / 43,441 miles) – 1,120% the size of Earth
  • Saturn (58,232 km / 36,184 miles) – 945% the size of Earth
  • Uranus (25,362 km / 15,759 miles) – 400% the size of Earth
  • Neptune (24,622 km / 15,299 miles) – 388% the size of Earth
  • Earth (6,371 km / 3,959 miles)
  • Venus (6,052 km / 3,761 miles) – 95% the size of Earth
  • Mars (3,390 km / 2,460 miles) – 53% the size of Earth
  • Mercury (2,440 km / 1,516 miles) – 38% the size of Earth

Galaxy is full of starless Jupiter-like planets

Finding new planets is interesting an remarkable, but finding a whole new class of planets – that’s definitely something extraordinary. University of Notre Dame astronomer David Bennett described just that – a class of planets without stars or a solar system, just wandering around the galaxy all by themselves.

The most likely theory is that these planets were ejected during the formation of solar systems; they found ten planets, all of which resemble Jupiter.

“Our results suggest that planetary systems often become unstable, with planets being kicked out from their places of birth by close encounters with other planets”.

What’s interesting about this discovery is that it indicates not only that there are huge planets just wandering about in space, but that there are quite many. Free floating planets are extremely hard to detect, so the fact that they found ten points towards many more starless planets. Also, it doesn’t indicate that it’s all about Jupiter-like ones.

“Our survey is like a population census — we sampled a portion of the galaxy and, based on these data, can estimate overall numbers in the galaxy,” Bennett said. “The survey is not sensitive to planets less massive than Jupiter and Saturn, but theories suggest that lower-mass planets like Earth should be ejected from their stars more often and are thus more common that free-floating Jupiters.”

Some researchers went extremely far, suggesting that these planets might actually harbor life, even without a star, due to an very powerful greenhouse effect caused by the enormous amounts of hydrogen in their atmosphere. NASA’s planned WFIRST mission will use the microlensing method to reveal how many free-floating Earth-mass planets inhabit the Milky Way galaxy.

How many planets are in the Milky Way? Over 50 billion

Yes, you’ve read that right. There are over 50 billion planets in our galaxy alone, according to the Kepler telescope, scientists now estimate that not only there are over 500 bilion planets in the galaxy, but that there are over 500 million life-cable planets out there as well.

These numbers obviously come from Nasa’s own database created by the Kepler telescope. The only telescope that was launched in space specifically for the discovery of planets in our own little slice of (intergalactic) heaven. The estimates come from counting how many planets have passed through Kepler’s view so far and extrapolating that number to the full size of the galaxy. As of now, Kepler has found no more than 1355 objects that have high chances to be planets and 54 of these are in the so called “Goldilocks’ zone or in a close enough orbit to a star to be perfect for sustaining life, a region that is neither too hot nor too cold.

If we do the math on this (which is exactly what the scientists did), since half of the stars have planets and that 1 star out of 200 has at least a planet in the Goldilocks zone,we draw the conclusion that there are over 300 billion stars in our very own galaxy, which may be only one of 100 billion galaxies that the old and trusty Big Bang created.

Life on other planets suddenly doesn’t appear all that imposibile, does it?

Astronomers upset the theory of planetary formation

The discovery of 9 new planets raises some serious questions on the matter of how planets are formed. Two astronomers from the University of California, Santa Barbara reported the discovery, and of them, two are spinning in the opposite direction the planets in our solar system are spinning. This, along with other recent studies of exoplanets (planets outside the solar system) seems to put the final nail in the primary theory regarding planetary formation.

hot-jupiter-4

Artistic illustration of a Hot Jupiter

This was the highlight at the UK National Astronomy Meeting in Glasgow, Scotland that took place this week, and now researchers from this field will have a whole lot of work to do, basically starting from scratch (almost).

“Planet evolution theorists now have to explain how so many planets came to be orbiting like this,” said Tim Lister, a project scientist at LCOGT. Lister leads a major part of the observational campaigns along with Rachel Street of LCOGT, Andrew Cameron of the University of St. Andrews in Scotland, and Didier Queloz, of the Geneva Observatory in Switzerland.

The 9 planets are pretty interesting by themselves too; they are so-called “Hot Jupiters”. As you could guess by the name, they are giant gas planets that orbit quite close to their star (which is of course why they’re hot). Since this type of planet was discovered no more than 15 years ago, their origin has remained a mystery. However, they are quite easy to detect due to the gravitational effect they have on their star.

The general belief is that at their cores, these planets have a mix of rock and ice particles found only in the cold outer reaches of planetary systems. The logical conclusion is that Hot Jupiters have to form quite far away from their star and then migrate closer as millions of years pass. Numerous astronomers believed this happens due to the interactions the planets have with the dust cloud from which they are formed. However, this idea does not explain why they orbit in a direction contrary to that of the disk.

Another theory suggests that it was not interaction with the disk at all, but rather a slower evolution that was affected by gravitational relationships with more distant planetary or stellar companions over hundreds of millions of years. It would probably be imposed an elongated orbit and would suffer have a “tidal” movement, until it was parked in a more circular orbit close to the star.

“In this scenario, smaller planets in orbits similar to Earth’s are unlikely to survive,” said Rachel Street.

New planet close to size of Earth found

The Planet

new_earth306Researchers have long been interested in finding other planets that have approximately the same size as our mother earth, because it’s estimated that they have the biggest odds of hosting life in a significant diversity. However, out of the over 400 planets that have been discovered so far, the vast majority resembles Jupiter rather than Earth.

Scientists using the Keck telescope in Hawaii discovered a new planet they’ve called HD156668b. Located in the Hercules constellation 80 light years away from us, this “Super Earth” has all the odds of being inhabited.

“This is quite a remarkable discovery,” said astronomer Andrew Howard of the University of California at Berkeley. “It shows that we can push down and find smaller and smaller planets.”

Of Super Earths

mantle-11Super Earths are planets with a mass relatively close to that of Terra; they are rather bigger than smaller (from 2 to 10 times bigger, actually). They have to be bigger, because if they are smaller (like Mars, for example) the interior would just not be hot enough to drive tectonics (tectonic plates slide on a layer of molten rock called a mantle, and convection currents make it move around).

But of course, even such a (relatively) small difference can cause significant modification in the planetary dynamics. With these bigger planets, the interior would of course be hotter, bigger, and the planetary crust would be thinner and would suffer more stress. The tectonic movement would be much active and as a result, earthquakes, volcanic eruptions and other such processes would take place way more often.