Tag Archives: Rosetta Probe

Life on comets? Not so fast, astronomers say!

Yesterday, we presented an article in which we detailed the claims of two astronomers, Director of the Buckingham Centre for Astrobiology professor Chandra Wickramasinghe and his colleague Dr Max Wallis from the University of Cardiff; they proposed that Rosetta’s lander Philae may have actually landed on an inhabited comet – as the black slime on the surface suggests. However, the rest of the astronomical community has been vocal in contesting these claims.

Image via ESA.

The Rosetta Probe is trailing 67P/Churyumov-Gerasimenko, and the Philae lander has woken up from its slumber on the comet and started transmitting once again. Upon analyzing the images and running some computer simulations, Wallis and Wickramasinghe came to the conclusion that the dark slime on the surface of the comet could be a result of microbial activity – but not everyone agrees (to put it mildly).

“No scientist active in any of the Rosetta instrument science teams assumes the presence of living micro-organisms beneath the cometary surface crust,” Uwe Meierhenrich of Université Nice Sophia Antipolis, France, reportedly told The Guardian in an email exchange on Monday afternoon.

Meierhenrich serves as a co-investigator on Philae’s COSAC instrument, which was designed to chemically analyse the comet. According to him, comet’s black surface crust was predicted all the way back in 1986 by J. Mayo Greenberg (Nature 321, 385), who calculated what would happen to organic, non-living molecules struck by cosmic rays and light.

“These explanations seem to be valid, also with regard to new data of the cometary Rosetta mission,” wrote Meierhenrich.

So not only do we have a perfectly rational explanation that doesn’t involve alien life on a comet, but we have an explanation that was proposed since the 1980s. Several prominent astronomers were vocal and

“I think it is highly unlikely,” Professor Monica Grady of the Open University told the paper. Grady helped design the stunningly sophisticated Ptolemy instrument carried by Philae, Rosetta’s lander.

Furthermore, according to members working on the Rosetta mission, if life were actually present on the comet, we would actually be able to pick it up. COSAC and the PTOLEMY instrument on Philae could measure levels of chemicals associated with living organisms.

“We can thereby well distinguish between the biological and astrochemical formation of organics,” wrote Meierhenrich.

Some scientists were a bit more firm in their statements. Professor Dave Rothery of the Open University posted in a comment on Facebook:

“The Guardian and the RAS disgraced themselves today with the ‘top scientists’ argue case for life on comet’ piece today. I’ve just sat through the talk behind the press release and I think it fair to say that the audience was polite but entirely unconvinced. Diatoms [a type of micro-organism] in comets, my arse!”

 

Philae could be sitting on a comet filled with alien life and not even know it

Comet lander Philae may be sitting on top of microbial life and not even know it – even worse, it has no way of figuring out if it actually is. According to two researchers, the comet’s characteristics (as well as computer simulations) might indicate that the surface may be teeming with microbes.

The black layer on the comet’s surface may be a result of microbial activity, scientists claim.

The Rosetta spacecraft was launched in March 2004 by the European Space Agency (ESA). Along with Philae, its lander module, its main goal was to perform a detailed study of comet 67P/Churyumov–Gerasimenko (67P); this was actually the first mission to orbit and study a comet up close. In late 2014, Philae successfully landed on a comet and obtained detailed images of the comet’s surface. On 15 November 2014, Philae entered its hibernation mode after its batteries ran down due to reduced sunlight, but in June 2015, Philae woke up and started communicating again, sending some important clues regarding potential alien life on the comet.

The comet has a black, organic-rich crust, which could with organisms making their way beneath its icy surface. Of course, there are other (more reasonable) explanations, but researchers seem adamant in their claims. If there is in fact life on comet 67P, then it would be nothing more than microbes, but these microbes would be huge (figuratively, not literally) – it would be mind boggling, which is why so many are skeptical about these claims.

Director of the Buckingham Centre for Astrobiology professor Chandra Wickramasinghe and his colleague Dr Max Wallis from the University of Cardiff have said that comet 67P and others like it may have significant populations of extremophiles on it – organisms that can survive in extreme conditions, like the ones on 67P.

“These are not easily explained in terms of prebiotic chemistry. The dark material is being constantly replenished as it is boiled off by heat from the sun. Something must be doing that at a fairly prolific rate,” Wickramasinghe said.

The comet has a black hydrocarbon crust overlaying ice, smooth icy ‘seas’, and flat-bottomed craters containing ‘lakes’ of re-frozen water overlain with organic debris.

To make things even more tantalizing, Wickramasinghe and Wallis conducted computer simulations which showed that it would be (theoretically) possible for microbes to survive on the comet. The astronomers present their case for life on 67P at the Royal Astronomical Society’s National Astronomy Meeting in Llandudno, Wales. Now, scientists are kicking themselves for not adding life-detection technology to Philae.

“I wanted to include a very inexpensive life-detection experiment. At the time it was thought this was a bizarre proposition,” Wickramasinghe added.

Furthermore, several cracks in the ice had been shown to be ‘spewing out material’ that is falling on to the surface, which also points to microbial activity.

“I think the microbiotic activity just under the surface results in gas which builds up to the point where the overlaying layers of ice can’t withstand the stresses,” said the professor.

If this were actually the case, if life actually exists on comet, it would be huge – potentially force us to rethink what we know about the very emergence of life. It also has vast implications for life on Earth; would life on Earth evolved by itself, or would have it been “seeded” by comets? But as strange and difficult to accept this may be, we have to keep an open mind.

“Five hundred years ago it was a struggle to have people accept that the Earth was not the center of the universe. After that revolution our thinking has remained Earth-centered in relation to life and biology. It’s deeply ingrained in our scientific culture and it will take a lot of evidence to kick it over,” Wickramasinghe said.

 

Rosetta to continue its mission and land on a comet

The European Space Agency has confirmed that the Rosetta mission will continue until at least September 2016, when it will most likely land on a comet called Comet 67P.

Comet 67P in September 2014. Image credits: ESA.

Rosetta is a robotic space probe built and launched by the European Space Agency. Along with Philae, its lander module, Rosetta is performing a detailed study of comet Churyumov–Gerasimenko (67P). In August 2014, Rosetta rendezvoused with the comet 67P and sent Philae to land on the comet, from which it gathered some extremely valuable information (such as water not coming from comets).

Now, the mission will be continued, and the probe itself might land on a comet by September next year – if everything goes according to plan.

“This is fantastic news for science,” said Matt Taylor, ESA’s Rosetta Project scientist. “We’ll be able to monitor the decline in the comet’s activity as we move away from the Sun again, and we’ll have the opportunity to fly closer to the comet to continue collecting more unique data. By comparing detailed ‘before and after’ data, we’ll have a much better understanding of how comets evolve during their lifetimes.”

The next comes after Philae woke up from its seven month hibernation which resulted after Philae which landed in an unintended, shadowed area on the surface of a comet in November and couldn’t recharge with solar energy. But on Friday, the lander sent two-minute radio transmissions to Earth, signaling its awakening.

“Among other things, we have received updated status information,” Michael Maibaum, deputy operations manager at the German space agency’s Lander Control Center in Cologne, said in a statement.“ At present, the lander is operating at a temperature of zero degrees Celsius, which means that the battery is now warm enough to store energy. This means that Philae will also be able to work during the comet’s night, regardless of solar illumination,” he said.

Rosetta’s orbit is currently being adjusted so Philae can have an easier time signalling back to Earth, and to prepare for the ultimate landing on the comet it’s been following around for so long.

“This time, as we’re riding along next to the comet, the most logical way to end the mission is to set Rosetta down on the surface,” said Patrick Martin, Rosetta Mission Manager.

Unfortunately though, even if Rosetta manages to land on 67P, it seems unlikely that it may manage to send data from there.

Artist's impression of the Rosetta spacecraft flying past an asteroid. Photograph: AP

Rosetta Illustrates the Miracles of Space Science

This is an article by Dave Syndergaard, professor in the Space Studies program at the American Public University.

Miraculous.

That’s the first word that comes to my mind when I think about the European Space Agency (ESA) mission to Comet 67P/Churyumov-Gersimenko. The Rosetta spacecraft and its lander, Philae, recently reached 67P after a 10-year round-trip journey of four billion miles.

 Artist's impression of the Rosetta spacecraft flying past an asteroid. Photograph: AP

Artist’s impression of the Rosetta spacecraft flying past an asteroid. Photograph: AP

Here’s where the “miracles” come in:

Miracle number one: Mission planners had to calculate a circuitous journey for Rosetta that included four fly-by’s of major planets, which increased its speed enough to reach the comet. Think of a 10-year, four billion mile journey that included zipping past planets and asteroids and culminated in getting close enough to the four-mile- wide comet to go into orbit around it and drop a lander on its surface.

The math and physics involved in rendezvous and proximity operations are daunting. Even though we’ve gotten pretty good at it since the first space rendezvous operations were conducted in the mid-1960s,  it had never been attempted before from this distance or with this oddly-shaped an object.

While 67P is a comparatively small rubble pile in space, it’s massive enough for its gravity to have an effect on both Rosetta and Philae. This means that scientists had to calculate and recalculate its mass and center of mass in real-time from Rosetta as they brought the spacecraft closer to the comet.

21JanRosettaSpaceWEB

Miracle number two: On June 8, 2011, after Rosetta zipped past asteroids 2867 Steins (September 5, 2008) and 21 Lutetia (July 10, 2010), mission managers put it into hibernation to conserve electrical power. Rosetta flew past the orbit of Jupiter, where sunlight is less than four percent of that on Earth.  For 31 months, it conserved power by not communicating with the Earth at all and generated only enough heat to keep the craft and its instruments from freezing.

Rosetta delivered a tiny amount of electricity to an alarm clock of sorts that roused the spacecraft from its sleep right on schedule on January 20, 2014. The scientists and engineers who were waiting for that signal had to believe that the spacecraft would be exactly where they had calculated it would be and that it would still be in working order.

Miracle number three: Touchdown. Starting in May, mission controllers conducted an intricate set of nine thruster burns that brought Rosetta alongside 67P on August 6.  About 60 miles from 67P, Rosetta fired its thrusters and entered orbit. After that, mission controllers decreased the orbital altitude to a final circular orbit around the asteroid at 12 miles above the surface.

On November 12, the 220-pound Philae lander, which had been attached to Rosetta’s side since launch, separated from Rosetta and descended for seven hours (without propulsion or guidance) and touched down on the surface of 67P. Bear in mind that Rosetta and Comet 67P are hurtling through space at approximately 41,000 miles per hour in an elliptical orbit around the sun.

Kepler’s Laws tell us the orbital velocity is constantly changing and increasing as 67P and Rosetta approach the sun. It’s no exaggeration to say that landing Philae on the surface of 67P was like landing a speeding bullet on another speeding bullet.

The Philae lander landed in the shadow of a cliff.  As a result, the lander’s solar panels aren’t receiving enough of the Sun’s energy, and Philae has powered down. Before it lost power, the lander sent back several exciting images as well as very useful science data. Just before they lost contact with Philae, mission controllers lifted and rotated the lander’s body in an attempt to receive more solar energy. The Rosetta team is confident that when the comet and lander get closer to the Sun, Philae’s solar panels will receive enough energy to allow the lander to power up and continue its mission.

Obviously this accomplishment was not, in fact, a miracle, but the culmination of hard work, expertise, determination, and checking and double-checking. All of this was done by men and women who once sat in undergraduate space studies classes dreaming of someday making a major contribution to science. That’s miraculous and inspiring.

Editor’s note:  Before Philae went offline, it relayed that it had found carbon molecules on the comet’s surface, a discovery with significant implications to the origin of life. 

Organic molecules found on comet

As we were telling you already in several articles, the Rosetta probe is in orbit of a comet – the 67P/Churyumov-Gerasimenko comet. But to make things even more exciting, Philae, Rosetta’s lander, also made contact with the comet; among other things, the lander found carbon molecules on the comet – the basis of life on Earth. Considering how comets are believed to have formed during the earlier stages of our solar system, this could also shed light on how life evolved on Earth.

The Philae lander found organic molecules on the surface of a comet.

Though Philae’s adventure on the comet was short lived (lasting only 60 hours), the lander sent home important data. The first important piece of information is that the comet has organic molecules on its surface; not so much has been released about the molecules so far – we only know that they are carbon molecules, not how complex and what type. Other analysis showed that the comet is covered in ice, with only a thin dust layer above.

Dr Fred Goessmann, principal investigator on the Cosac instrument, which made the molecule detection said that the team is still working on interpreting the results, and no additional information will be given until that is solved. This is only natural, because the stake is so high; they may provide crucial insight to the possible role of comets in contributing some of the chemical building blocks to the primordial mix from which life evolved on the early Earth. Let’s rewind a bit.

We still don’t know how life appeared on our planet. The earliest evidence for life on Earth comes from fossilized mats of cyanobacteria called stromatolites in Australia that are about 3.4 billion years old. There may have been other, earlier life forms, but they haven’t left any signs of their existence – or at least we haven’t found them. Still, the general idea is that life appeared sometime during that period. But even as scientists have a fairly good idea when life appeared, we still don’t know how it appeared.

“Many theories of the origin of life have been proposed, but since it’s hard to prove or disprove them, no fully accepted theory exists,” said Diana Northup, a cave biologist at the University of New Mexico.

Among the leading theories, there is the idea that crucial organic molecules came from outer space, through comets. Complex organic compounds, like amino acids, are the building blocks to life. The conditions on the young Earth were not favorable for making those compounds, and for this reason, many researchers believe they came from an outside source.

The discovery of the molecules was made with Philae’s Cometary Sampling and Composition Experiment (COSAC) instrument. Philae also inspected the ice on the surface of the comet. Because the temperature is so low, the ice has the tensile strength of a sandstone on Earth.

“It’s within a very broad spectrum of ice models. It was harder than expected at that location, but it’s still within bounds,” said Prof Mark McCaughrean, senior science adviser to Esa, told BBC News. People will be playing with [mathematical] models of pure water-ice mixed with certain amount of dust.”

There is still some doubt regarding the nature of the ice, but researchers are pretty certain.

“You can’t rule out rock, but if you look at the global story, we know the overall density of the comet is 0.4g/cubic cm. There’s no way the thing’s made of rock. It’s more likely there’s sintered ice at the surface with more porous material lower down that hasn’t been exposed to the Sun in the same way.”

Unfortunately, we can’t get a full picture yet. Scientists had to conduct as many analysis as possible before Philae’s battery ran out, but they weren’t able to conduct all the tests they planned.

“We didn’t necessarily see many organics in the signal. That could be because we didn’t manage to pick up a sample. But what we know is that the drill went down to its full extent and came back up again.”

“But there’s no independent way to say: This is what the sample looks like before you put it in there.”

But Philae is not gone for good yet – as the comet closes in on the sun, it will also recharge its batteries – unfortunately, this will also bring its demise.

 

Rosetta mission discovers the comet that “sings”

The Rosetta probe found a comet which “sings”. Image via ABC.

As I am writing this, the Rosetta mission’s lander, Philae, is mid way through its landing on a comet. If everything works out, this will be the first time humans have landed anything on a comet and will provide valuable information about not only the comet in particular, but also our solar system in general.

*UPDATE* Rosetta’s final ‘go’ has been given, the landing attempt will start today in just a few minutes!

But as Rosetta was zooming in on its destination, machines picked up a very strange signal coming from Comet 67P/Churyumov-Gerasimenko. Through some kind of interaction in the comet’s environment, 67P’s weak magnetic field seems to be oscillating at low frequencies. Scientists amplified the frequencies 10,000 times to make them audible for the human ear.


It’s still not clear exactly why this “singing” is happening, but researchers believe the oscillations may be driven by the ionisation of neutral particles from the comet’s jets. Basically, the comet’s nucleus and coma are surrounded by jets of vapor and dust which interact with the solar wind – a stream of plasma released from the upper atmosphere of the Sun, consisting mostly of electrons and protons.

As they are released into space, these particles become ionized, and because they are ionized, they interact with the comet’s magnetic field, causing the oscillations we have now picked up. But before a definitive answer is given, more research is needed.

“This is exciting because it is completely new to us,” says Karl-Heinz Glaßmeier, head of Space Physics and Space Sensorics at the Technische Universität Braunschweig, Germany. “We did not expect this and we are still working to understand the physics of what is happening.”

Hopefully, the mission will work out as planned and the lander will be successful in making its way on the surface of the comet. We’ll keep you posted!

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.