Tag Archives: probe

American probe is one month away from touchdown on asteroid Bennu

NASA’s OSIRIS-REx mission is nearing its objective — the asteroid Bennu.

A mosaic image of asteroid Bennu composed of 12 images collected by the OSIRIS-REx spacecraft. Image credits Flickr / NASA’s Marshall Space Flight Center.

The mission aims to sample at least 60 grams (2.1 ounces) of material from the asteroid 101955 Bennu and was launched in 2016. The craft itself has spent the last four years in transit to its objective and is expected to touch down on October 20, according to the agency.

If successful, OSIRIS-REx (which stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) will be the first U.S. mission to return from space with samples of an asteroid.

Parking far from home

“Years of planning and hard work by this team are essentially coming down to putting the TAGSAM (Touch-And-Go Sample Acquisition Mechanism) into contact with the surface for just five to 10 seconds,” said Mike Moreau, OSIRIS-REx deputy project manager.

In that short span of time, the craft will collect samples of rock and dust to bring back home for researchers to analyze. They hope to find more information on the early days of the solar system locked inside its chemical and geological make-up. Ideally, Bennu’s barren, rocky surface can help us better understand how planets and life came to be — including whether asteroids had anything to do with ‘seeding’ the building blocks of life on Earth.

NASA has chosen a spot some 16 meters (52 feet) in diameter called Nightingale as their landing spot. This will also serve as the sampling location. It was chosen because it’s the largest area we could identify that looks clear of debris, and was thus one of the best places where the craft’s robotic arm actually has a chance of retrieving the samples we need.

Still, this poses a challenge. The spacecraft is about the size of a van, and the space isn’t particularly large. Due to the distance between Bennu and Earth, any messages sent between them would need around 18.5 minutes to transmit. As such, the landing procedure will be performed autonomously.

Hopefully everything goes well. If it does, the lander should bring its samples back home sometime in late September, 2023.

NASA puts InSight experiment on hold because one stubborn rock is blocking their instruments

A key instrument on NASA’s Mars InSight rover has run into a problem — ground control suspects a stone.

Mars landing.

A rendering of a InSight Mission Candidate Landing Site made using topography data from the University of Arizona / NASA/.
Image credits Kevin Gill / Flickr.

The rover’s heat probe has struck an obstacle just below the red planet’s surface over the weekend and hasn’t been able to make progress since.

The Heat Flow and Physical Properties Package Problem

“The team has therefore decided to pause the hammering for about two weeks to allow the situation to be analyzed more closely and jointly come up with strategies for overcoming the obstacle,” Tilman Spohn, the principal investigator for the heat probe, wrote Tuesday in the mission logbook.

The instrument, known as the Heat Flow and Physical Properties Package, or HP³, was designed to hammer itself 16 feet (roughly 5 meters) into Mars’ underground and measure how much heat its interior leaks. This data would help researchers estimate the planet’s composition and history.

However, trouble is brewing underneath InSight — this probe (nicknamed the “mole”) encountered some kind of resistance underground over the weekend and hasn’t been able to make any progress since. Ground control (at the Jet Propulsion Laboratory in La Canada Flintridge, California) first tried to power it up last week. This first attempt failed to reach all the way to the Mars Odyssey orbiter, however, which was supposed to pass it on to InSight.

The mole was deployed last Thursday, after the team established a stable connection to the rover. It pushed its way in the red soil and made quick progress. For about five minutes. The next four hours of hammering failed to push the mole much deeper and eventually forced the device to one side — the mole is now lodged in the underground, leaning at about 15 degrees of vertical.

InSight.

Artist’s concept of InSight and its instruments.
Image credits NASA / JPL-Caltech.

Current estimates place the mole at a depth of around one foot (0.3 meters). This means that the probe — measuring some 16 inches (0.4 meters) in height — is partially sticking out of the ground. Despite this, the probe likely still is burrowed “deeper than any other scoop, drill or probe on Mars before,” which was its intended purpose.

Spohn writes that the team is a bit worried but that they “tend to be optimistic.” They’re currently working on the assumption that the holdup is a buried boulder or some gravel.

This particular spot was picked for InSight to land on as it appeared to be mostly sandy and soft. However, the team was aware that such a holdup was possible. Tests carried out at JPL suggested that the probe should be able to dig its way around small rocks or layers of pebbles. Since the second attempt to hammer away at the probe didn’t do that, the team decided to put the mole on hold. They’re currently waiting to receive more data from InSight, including pictures, so they can “better assess the situation.”

But not all is lost. The probe is still intact — that’s a really good thing — so it can actually start collecting data. The team has already put it to the task. HP³ will measure how quickly a generated pulse of heat spreads through the soil. Later this week, as (Mars’ moon) Phobos passes overhead and eclipse the sun over InSight the probe will also track how the event changes surface temperatures. While not its intended role, these readings should help the team make better sense of heat flow values in Mars’ soil if and when the probe is deployed as planned.

NASA cancels maneuver to get Juno closer to Jupiter due to faulty fuel valves — but that’s not bad news

NASA’s Science Mission Directorate has canceled a planned tightening of Juno’s orbit around Jupiter after system checks revealed faulty fuel valves on board the probe.

Image credits NASA / JPL.

Last year on July 4, the Juno probe reached its destination and settled in a comfortable 53-day orbit around Jupiter. On the closest point to the giant during every pass, it would deploy its sensor array and take as many measurements as possible, beaming the data back to Earth for study.

Researchers hoped to reduce Juno’s orbit around the gas giant down to just 14 days to speed up data acquisition from the craft. To do this, they planned on firing the craft’s main engine to reduce its speed and get it closer to Jupiter. Operational tests performed before the braking however showed the two helium check valves which supply the engine did not operate as expected when the system was fully pressurized.

“Telemetry from the spacecraft indicated that it took several minutes for the valves to open, while it took only a few seconds during past main engine firings,” a NASA status report on Friday read.

Rather than risk to lose control on Juno’s current orbit, NASA postponed the maneuver. Since then, researchers have been hard at work looking into how the burn can safely be performed in light of the new technical difficulties.

But it seems they weren’t very confident in their chances. Last week, NASA announced it will abort the maneuver rather than risk to irrevocably alter Juno’s flight path. The probe will maintain its current orbit around Jupiter.

“We looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit,” said project manager Rick Nybakken with NASA’s Jet Propulsion Laboratory in Pasadena, California. “The bottom line is a burn represented a risk to completion of Juno’s science objectives.”

The good news is that the probe can still perform its task, it will just take a little longer to do so. Both orbits would yield the same quality of data, as they would both take Juno just as close to Jupiter — some 2,600 miles (4,200 km) above the gas giant’s clouds.

Which is not a bad place to be at all, judging from the view.
Image credits Credits: NASA/JPL-Caltech/SwRI/MSSS/Roman Tkachenko.

“The worst-case scenario is I have to be patient and get the science slowly,” lead researcher Scott Bolton, with the Southwest Research Institute in San Antonio, Texas, said after the engine problem surfaced in October.

“The science will be just as spectacular as with our original plan,” he added on Friday’s release.

“In fact, the longer orbit provides new opportunities that allow further exploration of the far reaches of space dominated by Jupiter’s magnetic field, increasing the value of Juno’s research,” the statement added.

Another upside of canceling the burn is that a more distant orbit will extend the craft’s operational life. Jupiter’s massive radiation belts were the main killer for Juno, and staying well away from them should better protect its systems.

In light of its extended operational life, Nybakken will probably request additional funding for the US$1.13 billion mission, currently scheduled to end on July 31, 2018 — when Juno would have completed its observations and become inoperable under the effects of radiation. The extended mission now aims at completing 12 close approaches.

Juno has proven instrumental in our understanding of how gas giants form and behave. If you want to take a more active part in its research, you can vote on which features of the planet will be imaged during each flyby in the JunoCam project set up by NASA. It’s the closest you’ll ever get to be an astronaut without even leaving your chair.

NASA creates computers that can survive on Venus, 30 years after the last landings

NASA’s Glenn Research Center has developed a new class of computers that can withstand the hellscape of Venus. The devices are built from a different semiconductor than regular hardware, which can carry more voltage at much higher temperatures.

SiC transistor gate electroluminesces blue while cooked at more than 400°C.
Image credits NASA / Glenn RC.

Mars has been getting a lot of attention as humanity’s first planned colony. So it’s easy to forget that it’s neither the closest nor the most Earth-like terrestrial planet in the Solar System. Both those distinctions belong to Venus — so why aren’t we looking towards it for our otherworldly adventures?

The goddess of love and beauty

Well, the thing is that Venus is awful. It’s an objectively dreadful place, a scorching hot ball of rock covered in thick clouds of boiling acid. Ironic, right?

These conditions not only make it nigh-impossible for real-estate agents to put a positive spin on the planet, it also makes it frustratingly hard to explore. Any mission to Venus has to work around one simple fact: your run of the mill computer wouldn’t like it there. Normal silicone chips can still function up to 240-250°C (482°F). After that, the chip turns from a semiconductor into a fully fledged conductor, electrons start jumping all over the place, and the system crashes.

The longest any human-made object has made it on Venus is 127 minutes, a record set in 1981 by the Soviet spacecraft Venera 13. It was designed to survive for only 32 minutes and used all kinds of tricks to make that happen — such as cooling of internal systems to -10°C (14°F) before entering the atmosphere, hermetically sealed internal chambers for instruments, and so on. Venera braved sulphuric rain, surface temperatures of 470°C (878°F), and an atmosphere 90 times that of Earth long enough to capture the first color pictures of the planet’s surface.

The face of love.
Image credits Morbx / Reddit.

After the mission, the Soviets flew three more crafts to Venus — Venera 14, Vega 1, and Vega 2 — making the last attempted landing on the planet in 1985.

Since that time, the transistor industry has developed alternative materials it can use for integrated systems. One of the most promising class of materials are silicon carbides (SiC). Their ability to support high voltages at huge temperatures has already drawn interest from the military and heavy industries, and make them ideal for a mission to Venus.

NASA’s Glenn Research Center has developed two prototype SiC chips which can be used in future Venus missions. The researchers have also worked to overcome another vulnerability of traditional integrated circuits: they’ve developed interconnects — the wires that tie transistors to other hardware components — which can withstand the extreme conditions on the planet.

Five hundred hours of fire

SiC chip designed by NASA, before and after GEER tests.
Image credits NASA / Glenn RC.

To see if the technology lives up to expectations, the team put these SiC transistors and interconnects together and housed them in ceramic-packed chips. The chips were then placed in the GEER (Glenn Extreme Environments Rig) which can simulate the temperatures and pressures on Venus for hundreds of hours at a time.

One of the chips, housing a simple 3-stage oscillator, kept stable at 1.26MHz over 521 hours (over 21 days) before the GEER had to be shut down. The second chip fizzled out after 109 hours (4,5 days), but NASA determined that it was caused by faulty setup, not the chip itself.

The results for the two chips. Image credits NASA / Glenn RC.

This performance is a far cry from that seen in the 80’s, especially considering that the chips didn’t benefit from any pressure vessels, cooling systems, or other types of protection. It’s the first system shown able to withstand the condition on Venus for weeks at a time.

“With further technology maturation, such SiC IC electronics could drastically improve Venus lander designs and mission concepts, fundamentally enabling long-duration enhanced missions to the surface of Venus,” the researchers conclude.

But it’s not only transistors we’ll need for a successful Venus rover. Drills, cameras, wheels — everything has to be adapted to work in a high pressure, high temperature, highly acidic environment. Materials science has evolved a long way since the last missions, so creating a mechanically-sound lander should be feasible. A full-fledged rover with multiple moving parts that can survive on Venus would be a lot harder to develop — NASA Glenn is working on such a machine, a land-sailing rover, which they estimate will be ready by 2033.

The full paper “Prolonged silicon carbide integrated circuit operation in Venus surface atmospheric conditions” has been published in the journal AIP Advances.

NASA plans to send an autonomous submarine into space — for a very good reason

NASA plans to explore Saturn’s moon Tian with an unlikely type of vehicle: a submarine. The agency is working on the design of an autonomous submersible that will explore the liquid hydrocarbon oceans of the moon.

The current design of the craft.
Image credits NASA.

The vehicle will have to endure bone-shattering cold as it will peer through the liquid methane and ethane oceans that cover the moon’s surface, relaying valuable data back to Earth, announced Jason Hartwig at the NASA Innovative Advanced Concepts (NIAC) Symposium last week. Its blueprints include a huge communications “fin” on the back of the sub that will allow it to cover the 1,492 million kilometer (886 million miles) span of space to communicate directly with Earth.

The submarine will be 6 meters (20 feet) long and will use Titan’s liquid methane instead of water in its ballast system. Its array of instruments will include meteorological tools, a sonar and radar, and an array of other sensors including cameras to take snapshots of what’s going on on the frigid moon.

The vehicle will be optimized to be as fuel efficient as possible, as chances of re-fueling are slim on Titan.

Ten thousand leagues over the ocean

Titan’s hydrocarbon oceans may be incredibly cold and seem strange to us, but scientists are interested in learning all they can about it as it resembles the conditions we think shaped an early Earth. It’s the only other known body in the Solar System that has stable, liquid seas on its surface. Titan’s atmosphere also functions similarly to our own, having its own hydrological (hydrocarbon?) cycles that dictate how liquids move from fresh to salt or from a gas, to a liquid, or a solid.

Artist rendering of a possible submersible bot exploring one the floor of one of Titan’s methane lakes. Image: NASA JPL

Artist rendering of a possible submersible bot exploring one the floor of one of Titan’s methane lakes. Image: NASA JPL

NASA wants to send a sub there because of its versatility. It can be used to measure waves, atmospheric composition and wind speeds on the surface, but can also analyze the composition of its seas or take sea floor samples after it submerges.

“If you can get below the surface of the sea, and get all the way down to the bottom in certain areas, and actually touch the silt that’s at the bottom, and sample it and learn what that’s made of, it’ll tell you so much about the environment that you’re in,” said Michael Paul from Penn State University, one of the researchers working on the project.

The submersible will also look very any signs of extraterrestrial life, as some experts believe the hydrocarbon soup can act as a replacing solvent for water to foster life.

“Think about life on Earth—we’re all either in water or we’re fancy bags of water,” says astrobiologist Kevin Hand of the Jet Propulsion Laboratory. “On Titan, life in the lakes would be ‘bags’ of liquid methane and/or ethane. That 90[Kelvin] liquid would be the solvent and then whatever is dissolved into the lakes would be the material that’s used to build the other components needed for life, and to power metabolism.”

The design efforts for the craft are on hold for now, as the agency awaits for more information on the moon’s oceans from the Cassini probe. New information about the depths, pressures, and temperatures of Titan’s oceans will be used to better tailor the sub to the environment it will function in. NASA hopes to reassess the project by March 2017.

But after the design is finalized and the sub built, that’s when the real waiting begins — its first mission has been tentatively scheduled for 2038.

That’s quite a wait.To help us pass the time, the guys and gals from NASA put together this teaser for the submarine. Enjoy!

 

Rosetta spacecraft finds huge sinkholes on comet’s surface

Rosetta is a robotic space probe built and launched by the European Space Agency. Along with Philae, its lander module, the craft is performing a detailed study of comet 67P/Churyumov–Gerasimenko.

The probe usually orbits 67P at a distance of a few hundred kilometers. Footage received from Rosetta over the last year showed a number of dust jets coming from the comet, which we expected to see. But, after analyzing high-fidelity images from the lander’s OSIRIS instruments, taken just ten to 30 km from the comet’s center, scientists saw that at least some of the dust jets come from specific locations on the comet’s surface, being projected from huge sinkholes.

The scientists have picked out 18 quasi-circular pits in the northern hemisphere of the comet, some of which are still active now. Each sinkhole is anywhere from a few tens of metres to hundreds of metres in diameter and go below the surface by up to 210m to a smooth dust-covered floor.

A catalogue of sinkholes spotted by Rosetta on comet 67P/Churyumov-Gerasimenko.
Image via: forbes.com

“We see jets arising from the fractured areas of the walls inside the pits. These fractures mean that volatiles trapped under the surface can be warmed more easily and subsequently escape into space,” says Jean-Baptiste Vincent from the Max Planck Institute for Solar System Research, lead author of the study.

Similar to the ones on Earth, these sinkholes form when a cavity opens up under the surface. As it widens and deepens, the loss of material makes the ceiling too thin to support its own weight, and collapses. After the collapse, the volatile materials can evaporate or be eroded more easily, and the sinkhole enlarges over time.

“Although we think the collapse that produces a pit is sudden, the cavity in the porous subsurface could have growing over much longer timescales,” says co-author Sebastien Besse, of ESA’s ESTEC technical centre in the Netherlands.

So, what caused these cavities to form in the first place? The team has three theories that they are pursuing.

The first one is that they are artifacts of the comet’s weak gravitational field. When it formed, material accreted by means of low-velocity impacts, leaving behind void areas due to the imperfect fit between primordial building blocks. Over time, seismic events or space impacts cause the surface to weaken enough to cause it to collapse.

Another possibility is that the pits are full of volatile ices like carbon dioxide and carbon monoxide, sitting just beneath a layer of dust. These ices could be melted by the warmth of the Sun as the comet draws closer in its orbit every year.

Or it could be that the ice manages to melt itself away by transforming from amorphous ice made up of irregularly packed molecules to crystallised ice, a process that would release heat which could be sufficient to cause evaporation.

Close-up photo of sinkholes on 67P.
Image via: esa.int

“Regardless of the processes creating the cavities, these features show us that there are large structural and/or compositional differences within the first few hundred metres of the comet’s surface and the cavities are revealing relatively unprocessed materials that might not otherwise be visible,” says Besse.

Researchers analyzing the interior structure of the sinkholes found that their interiors differ quite significantly, with some showing fractured material and terraces, others showing horizontal layers and vertical striations and others also showing globular structures nicknamed “goosebumps”.

“We think that we might be able to use the pits to characterise the relative ages of the comet’s surface: the more pits there are in a region, the younger and less processed the surface there is,” explains Vincent. “This is confirmed by recent observations of the southern hemisphere: this is more highly processed because it receives significantly more energy than the northern hemisphere, and does not seem to display similar pit structures.”

Active pits on Churyumov-Gerasimenko.

Rosetta scientists are hopeful that the spacecraft might yet get to see the formation of a sinkhole in action. The probe did see one outburst during its approach to the comet back in April 2014, which generated between 1,000kg and 100,000kg of material. But although a pit collapse could have been responsible for this, it was much smaller than the researchers expect.

With the collapse of a typical large pit of 140m wide and 140m deep, the team would expect to see the release of around a billion kilograms of material.

“Being able to observe changes in the comet, in particular linking activity to features on the surface, is a key capability of Rosetta and will help us to understand how the comet’s interior and surface have evolved since its formation. And with the extension of the mission until September 2016, we can do the best job possible at unravelling how comets work” says Matt Taylor.

 

 

 

The Rosetta Probe Prepares for First Ever Comet Landing

Launched by the European Space Agency (ESA), the Rosetta probe is nearing a crucial part in its mission – it will soon send a lander carrying 10 instruments on a comet. It will be the first time mankind lands anything on a comet, and the study could provide valuable information about comets and our solar system in general.

Rosetta probe comet.

Comet 67P on 19 September 2014 NavCam mosaic. Image via ESA.

You can watch the landing here just as it takes place, thanks to live streaming from the ESA. The scheduled time is 0835 GMT on Wednesday.

Rosetta is a robotic space probe built and launched by the European Space Agency to perform a detailed study of comet 67P/Churyumov–Gerasimenko. The probe is already orbiting the comet and has revealed the most accurate topography of a comet. Rosetta started scientific operations on 7 May 2014, while still at a distance of almost two million km from the comet; then, the comet was less than a pixel on the probe’s screen, but it soon started to reveal its secrets.

The first thing astronomers noted is the shape of the comet, which was significantly different from what they were expecting, based on telescope observations. They then learned that the comet is much warmer than what was previously believed, and the info keeps coming in. Now, astronomers and engineers want to take it to the next level, and actually land the Philae probe on the comet – in an attempt to find out not only how the comet is, but how our solar system came to be.

The currently accepted theory is that most comets are primordial ice and carbon dust left over from the building of the Solar System, doomed to circle the sun in varying orbits, ranging from a few years to a few thousand years.

Early Wednesday, scientists at the mission control center in Darmstadt, Germany, will decide whether to give Rosetta the go-ahead to release its lander, Philae. The atmosphere at the ESA headquarters is very tense, as the maneuver is difficult and perilous for the lander. Also, there was a bit of worry on Monday, as Philae “took a bit longer than expected” to be activated, said Paolo Ferri, mission leader at Darmstadt.

“We were a bit worried at first that the temperature would be wrong (for the descent) but it all worked out. We didn’t lost any time,” Ferri said. “The robot’s batteries should be charged up by tonight.”

Matt Taylor explaining Rosetta’s scientific operations to journalists at ESOC. Credit: ESA/C.Carreau

Every tiny inaccuracy or miscalculation could spell disaster, sending the 100-kilogram (220-pound) landing craft smashing onto the comet; and what a shame it would be! Philae has traveled 6.5 billion kilometres (four billion miles) on Rosetta, but the last 20 km will be the most dangerous. In order to successfully reach the comet, the lander must perform a complicated ballet, coordinated from home.

The Rosetta mission was approved all the way back in 1993, and it’s one of the more ambitious space projects. It would be the first time we would land something on a comet, an extremely difficult and rewarding task.

Europe to lead ambitious Sun mission

Europe aims for the stars: known as the Solar Orbiter will fly towards the Sun and get closer to it than any other man made object has; also, ESA will launch two other missions with the purpose of studying dark matter and dark energy.

Closer to the Sun

The mission was adopted today, and it will cost almost one billion euro. NASA will also participate in the mission, providing two instruments for the probe and the rocket which will launch it on its way, but this very ambitious mission is Europe’s project – and everybody from the ESA seems very proud:

“And I’m really looking forward to Solar Orbiter, which will become the reference for solar physics in the years to come,” said Alvaro Gimenez, ESA’s director of science.

A launch date hasn’t been officially proposed yet, but somewhere around 2017-2019 seems quite likely, if anything doesn’t change significantly. The probe will orbit around the star, staring directly into the furnace; but staring isn’t its primary job.

“Solar Orbiter is not so much about taking high-resolution pictures of the Sun, although we’ll get those; it’s about getting close and joining up what happens on the Sun with what happens in space,” explained Tim Horbury from Imperial College London and one of Solar Orbiter’s lead scientists.

There are some phenomena around the sun which we have only a basic understanding of.

“The solar wind and coronal mass ejections – these big releases of material coming off the Sun; we don’t know precisely where they’re coming from, and precisely how they’re generated. Solar Orbiter can help us understand that.”

Dark energy and dark matter

The ESA delegates, who were meeting in Paris, also approved a mission to investigate two of the great mysteries of modern cosmology – dark matter and dark energy. Some physicists are convinced that these phenomena dictate and shape the way our Universe evolves. The Euclid telescope will map the distribution of galaxies to try to get some fresh insight on these dark puzzles.

Just like the solar orbiter, the Euclid telescope will cost around 1 billion euro, but it still needs to pass some legislative hurdles in order to be approver, so a launch will probably not occur until 2019.

“They are both exciting missions, and it was really good to hear today that the physics Nobel Prize was awarded to research on the accelerating Universe, which is of course linked to Euclid,” mister Himenez added.

Euclid has the Herculean task of mapping out the spread of galaxies and clusters of galaxies over 10 billion years of cosmic history, as well as mapping their 3D distributon. The patterns of huge voids that exist between galaxies can offer important clues about the expansion of the cosmos through time – expansion which appears to be accelerating as a consequence of some unknown property of space itself referred to by scientists as dark energy.

“Euclid will give us an insight into how structures in the Universe are growing and whether they are growing at the rate we expect from General Relativity (our theory of gravity on large scales),” said Bob Nichol, a Euclid scientist from Portsmouth University.

But there’s even more.

“But aside from all that, Euclid should also deliver a picture of the Universe that has Hubble clarity over the whole sky. Euclid will detect billions of objects and they will all be there for us to go look at. And when we look back 50 years from now, that could be the one thing about Euclid we all say was worth it – a tremendous legacy for our children,” he told BBC News.

NASA passing the torch

The European Space Agency wants to launch this project on its own, but that could change pretty quick, as the Americans are desperate to run a similar mission they call WFirst (Wide-Field Infrared Survey Telescope); however, due to the huge budget costs NASA underwent, it is likely that it won’t even be approved until Europe’s one has launched already – thus giving Europe a huge advantage in one of the most important fields of modern astrophysics. Thus, ESA has offered to give NASA a 20% part in this affair.

“The door is always open to the Americans, and we are ready to co-operate with them if they come with a reasonable proposal,” said Dr Gimenez.

All in all, ESA seems to be moving, slowly but certainly in the right direction, and in the decades to come, it’s quite possible for it to become the leading edge in space exploration and astrophysics.

Via BBC

Saturn’s moon full of geysers

saturn-moon-geysers1-100223-02

There are many things we have yet to find out about Saturn, but the Cassini probe has definitely shed some light on the planet, and will surely do the same in the following years.

The most recent flyby showed a significant number of geysers just waiting to pop out from under the surface – even more than previously believed. The pictures taken show them in great detail, and by taking photographs across a period of time, researchers can understand their activity and overall planetary influence.

“This last flyby confirms what we suspected,” said Carolyn Porco, Cassini’s imaging team lead at the Space Science Institute in Boulder, Colo. “The vigor of individual jets can vary with time, and many jets, large and small, erupt all along the tiger stripes.”

“The fractures are chilly by Earth standards, but they’re a cozy oasis compared to the numbing 50 Kelvin (minus 370 Fahrenheit) of their surroundings,” said John Spencer, a composite infrared spectrometer team member based at Southwest Research Institute also in Boulder. “The huge amount of heat pouring out of the tiger stripe fractures may be enough to melt the ice underground.”

With the Cassini mission prolonged until 2017, we’ll definitely be hearing from the frozen giant quite soon.

Water and fog found on Titan, Saturn’s moon

As I was writing in a previous post, Titan is quite unique, in that aside from our planet it’s the only place in our solar system where significant quantities of liquid are to be found (though most are liquid ethane and methane). That doesn’t seem to make much of a difference considering the chemistry of it, but according to astronomer Mike Brown of the California Institute of Technology (Caltech) mother Earth and Saturn’s moon share another important characteristic: they have common fog. That implies there is an exchange of material between the atmosphere and the planet surface, a phenomenon previously only known to take place on our planet. It also shows there is an active hydrological cycle taking place.

titan5km_huygens

The Cassini probe has once again proven it’s value; the Visual and Infrared Mapping Spectrometer (VIMS) onboard the probe provided the data that eventually led to this conclusion. They found what could be described as isolated clouds at approximately 750 meters above the surface, and not higher, where clouds are usually formed. So the conclusion was simple: they found fog.

“Fog—or clouds, or dew, or condensation in general—can form whenever air reaches about 100 percent humidity,” Brown says. “There are two ways to get there. The first is obvious: add water (on Earth) or methane (on Titan) to the surrounding air. The second is much more common: make the air colder so it can hold less water (or liquid methane), and all of that excess needs to condense.”

Illustration of a view from Titan

Illustration of a view from Titan

He explains that this is the exact same process that causes water droplets to take shape on the outside of a very cool glass.

“That fog you often see at sunrise hugging the ground is caused by ground-level air cooling overnight, to the point where it cannot hang onto its water. As the sun rises and the air heats, the fog goes away.”

However, for some reason, this mechanism doesn’t work on Titan because the planet’s atmosphere causes extremely slow cooling or warming.

“If you were to turn the sun totally off, Titan’s atmosphere would still take something like 100 years to cool down,” Brown says. “Even the coldest parts of the surface are much too warm to ever cause fog to condense.”

He was asked if it could be all about mountain fog, but he rejected this categorically.

“A Titanian mountain would have to be about 15,000 feet high before the air would get cold enough to condense,” he says