A while ago we looked at those lizard people from Doctor Who, and how they hid underground to avoid an impending collision with the approaching Moon, according to a 40-year-old theory about its formation.
Obviously, this is all made up. And now we know better about how the Moon was formed: it wasn’t captured into orbit at all, but instead formed from the debris of a collision with an object about the size of Mars, around 4.4 billion years ago.
But this actually raises its own dilemma of how the fragile ingredients of life – the carbon, oxygen and hydrogen that make up organic molecules – avoided being blown off into space in such a cataclysm.
Well, it now seems possible that those elements were locked up in chains of formaldehyde (CH2O). Formaldehyde is, of course, very poisonous, which is why it’s good for preserving things in jars because no bacteria are going to go near it.
But it’s also capable of reacting with itself to form polymers that can survive extreme conditions – including temperatures as high as 1400 °C – which may have been the thing that prevented the precursors of life from boiling away into space.
This idea was suggested recently by George Cody, from the Carnegie Institution of Washington, and his colleagues (Cody GD, Heying E, Alexander CMO, Nittler LR, Kilcoyne ALD, Sandford SA & Stroud RM, “Establishing a molecular relationship between chondritic and cometary organic solids”, Proceedings of the National Academy of Science, published online April 4, 2011).
It was already known that formaldehyde is common in interstellar clouds, but what Cody et al. showed was that formaldehyde polymers could lead to the types of organic molecules found on comets (which have been sampled with probes) and carbonaceous chondrites, a type of meteorite. And these organic molecules are very similar to the compounds that would have been needed to kick-start life on Earth.
So, formaldehyde: quite capable of preserving the ingredients of life just like it preserves heads in jars. But it is poisonous, so be careful to keep your spaceship windows closed when you’re flying through interstellar gas clouds.
Read more about this research at Discovery News.