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n2doc

(47,953 posts) Thu Jul 30, 2015, 02:56 PM Jul 2015

All the Amazing Stuff We Just Learned About Philae's Comet

Although the European Space Agency's Philae comet lander has been incommunicado since July 9, today marks what's easily one of the most significant days in the lander's lifetime. That's because scientists across the globe working with the plucky robot have just released their first wave of discoveries and scientific research collected during Philae's slow rendezvous and inadvertently bouncy landing on comet C-G last fall. The research is published in seven papers in the journal Science.

"Last November we landed on this comet—a completely new world unlike anything humans have ever seen, and so much more different than we expected or could expect" Stephan Ulamec, the head of the Philae lander mission at the German Aerospace Center, told Popular Mechanics. In conducting this first wave of research, he says, "we've discovered that the surface of the comet is quite complex and variable, with a few structures that remind one of Mars, and that there is a high content of organic material."

One of the most interesting discoveries announced today was, ironically, only made possible by Philae's unfortunate failed landing. That's when the bot bounced several times across the surface of the low-gravity comet after its downward thruster and twin harpoons both malfunctioned and failed to anchor it.

Jens Biele, a geophysicist with the Philae team, lead a research group that not only mapped the bouncy landing with extreme detail, but also used the footprints left by Philae's unexpected journey (along with the lander's internal measurements) to investigate the makeup and hardness of the comet's topsoil. "That's data that you absolutely have to travel to the comet to acquire, there's no way we could have figured this out from orbit," says Biele.

He reports that Philae's initial touchdown site, (originally called "Site J," now named Agilkia) is covered with a dust of rocky regolith about 8 inches deep. "It's soft like snow," he says, noting that even just a decade ago, many scientists were still unsure if a comet like C-G would have been covered in many, many feet of downy-soft dust. If that were true, it would have enveloped Philae.

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http://www.popularmechanics.com/space/deep-space/news/a16683/new-studies-comet-lander-philae/

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All the Amazing Stuff We Just Learned About Philae's Comet (Original Post) n2doc Jul 2015 OP

Philae poses comet chemistry conundrum muriel_volestrangler Jul 2015 #1

muriel_volestrangler

(101,321 posts)

1. Philae poses comet chemistry conundrum

Reply to n2doc (Original post)

Thu Jul 30, 2015, 05:13 PM

Jul 2015

As the Philae lander bounced across comet 67P/Churyumov–Gerasimenko’s surface in November last year, two chemical instruments were able to take tentative – but intriguingly contradictory – sniffs of its environment. Those mass spectrometry measurements provide compositional details important for deciphering the origins of life on Earth, a key aim of the Rosetta mission that carried Philae. But while the cometary sampling and composition (COSAC) instrument detected 16 organic molecules, half of which contain nitrogen atoms, Ptolemy reports very low concentrations of nitrogen-containing compounds.

Nevertheless, Jen Blank, a senior scientist at the Nasa Ames Research Center in California, US, highlights the historic achievement of syncing orbit with a comet and sending a lander down to the surface. ‘The Philae data are amazing,’ enthuses Blank, who’s studied how comets may have supplied Earth with molecules needed for life, but wasn’t involved in Rosetta or Philae. ‘These are the first measurements of organic compounds collected directly on a comet or asteroid.’
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The compounds COSAC identified included methyl isocyanate, acetone, propionaldehyde and acetamide, which have not previously been reported in comets. Acetamide is also one of four compounds detected that can produce important biological molecules like amino acids, sugars and DNA bases. Blank is especially excited by acetamide’s presence. ‘It's easy to imagine a pathway to an amino acid,’ she says. However, Goesmann is cautious not to read too much into their presence. ‘Comets with such a composition do not work against life,’ he tells Chemistry World. ‘In the right environment, emerging life could make use of it.’
However, the small amount of material COSAC was looking at meant it couldn’t detect anything but the smallest compounds. That means it wouldn’t have seen any ‘molecules of life’, such as amino acids, even if they were present. And although it could have, it didn’t see much ammonia, formaldehyde or carbon dioxide, which are common components of cometary ice, or any sulfur compounds. The COSAC scientists link the lack of ice to measurements previously made by Rosetta showing 67P’s surface is covered in a carbon-based coat rather than frozen.

http://www.rsc.org/chemistryworld/2015/07/philae-poses-comet-chemistry-conundrum

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