Philae finds building blocks for life in its cold, comet grave

31 Jul 2015

Comet 67P from 1km away, via ESA/Rosetta/Philae/ROLIS/DLR

It’s been months since a humble spacecraft called Rosetta stalked a comet, dropped a scientist onto its surface, and waited to hear back. And now, at last, the results are in.

Philae’s on-again, off-again relationship with its scientists back on Earth has proved a soap drama in its storyline, with an explosive start seeing it whizz out of Rosetta and down onto 67P/Churyumov-Gerasimenko.

It landed heavily after its reverse thrusters failed and then spun 2km away, taking two hours, a bang on the head from a crater rim, and another bounce before settling down at the very edge of what scientists claim was the only place we’d hear back from.

Hurt, on its side and having damaged some of its receivers, Philae gradually declined and eventually ‘went dark’. All was lost.

Philae's descent

Philae’s descent down to 67P

But then, months later it spruced up and send home some communiqué. All was not lost.

But now Rosetta is on the other side of the comet, unable to receive many communications until next month, and we’ve heard nothing for weeks.

Look, don’t listen

What we have just gotten to read, though, is all the scientific work Philae did during it’s opening 64 hours – revealing that comet 67P has plenty of the ingredients needed to form life.

‘We’ve now discovered the comet is more like a hardware shop — lots of pre-made building blocks, like door frames, bricks etc’

ESA researchers have produced seven separate papers on all the findings, highlighting an array of organic compounds that play a key role in the prebiotic synthesis of amino acids, sugars and nucleobases – life’s building blocks.

The right place, the right time

For example, formaldehyde is implicated in the formation of ribose, which ultimately features in molecules like DNA.

It means that were the comet to make impact with a planet with the right head, the right atmosphere and the right set-up, life could form.

All these discoveries are thanks to the heavy landing, filling two of the spacecraft’s measurement tools – COSAC and Ptolemy – with dust and granules that were investigated after this nice bit of luck.

Philae's descent

Comet 67P’s surface, via ESA/Rosetta/Philae/CIVA

Ptolemy detected the main components of coma gases – water vapour, carbon monoxide and carbon dioxide, along with smaller amounts of carbon-bearing organic compounds, including formaldehyde.

COSAC, meanwhile, found 16 different compounds, including four – methyl isocyanate, acetone, propionaldehyde and acetamide – that have never before been detected in comets.

Frozen primordial soup?

The vast array of readings has lead one of the scientists working on the project to call comet 67P a giant “frozen primordial soup”, given that this is life, pre… life.

“It’s the kind of stuff that if you had it, and warmed it up somehow, and put it in the right environment, with the right conditions, you may eventually get life forming out of it,” said Prof Ian Wright of the Open University, who leads Ptolemy.

“What we may be looking at here is our abiological ancestral material — this is stuff that went into the mix to produce life. In many ways it’s quite a humbling thing to be working on, because this is life before life happened.”

This is not how the project was planned, with Philae meant to land safely and drill into the top soil to take samples. Instead the heavy landing threw comet substances everywhere, some landing into COSAC, some into Ptolemy.

What’s more, the scenic route Philae took lead to a vast array of images from parts of the comet we otherwise would have missed. What’s notable, too, is that the collision with the crater rim (see below) was one of the key moments of fortune, sending Philae to an accessible landing zone.

Philae landing site

Philae’s touchdowns, via ESA/Rosetta/Navcam/Sonc/DLR

The senior science adviser to the ESA put it better when he described comet 67P as a hardware shop.

“Imagine you want to build a house and you go to a forest, where there are trees, mud and rocks. You could make a house out of that, but it would be hard work,” said Prof Mark McCaughrean.

“Well, we’ve now discovered the comet is more like a hardware shop — lots of pre-made building blocks, like door frames, bricks etc. It gives you a head start.”

Rosetta returns to the hemisphere of 67P that Philae is sleeping on late next week, which is the next time that we might, hopefully, hear from our frozen little hero.

Until then, be safe in the knowledge that, had everything gone to plan and Philae landed where it was supposed to, it would have overheated by now and we’d have nothing left to hope for.

Gordon Hunt was a journalist with Silicon Republic