When we think about whether or not aliens exist, we generally imagine them on a vaguely Earth-like planet circling a distant star. We do not normally think of them living out in space itself.
But maybe that is not such a ridiculous idea. In April 2016, researchers reported that some of the key building blocks of life can be produced from simple substances under harsh conditions mimicking those of interstellar space.
Cornelia Meinert at the University of Nice, France and colleagues showed that a mixture of frozen water, methanol and ammonia – all compounds known to exist in the vast “molecular clouds” from which stars form – can be transformed into a wide range of sugar molecules when exposed to ultraviolet rays, which pervade space. The sugars included ribose, which is a part of the DNA-like molecule RNA.
This suggests that the fundamental molecules of life might be formed in outer space, and then delivered to planets like Earth by icy comets and meteorites.
Read her entire report here.
This might breathe some new life into the old panspermia hypothesis; the idea that life came to Earth (and, presumably, other life-friendly planets) from space, delivered by comets or other random impacting objects.
The BBC article goes a step farther, implying that simple life forms may exist in open space, or more likely on rogue planets that wander the spaces between stars. On that score, color me skeptical; interstellar space is an awfully hostile environment. Still, the humble tardigrade of Earth can survive some awfully hostile environments, and bacterial spores are likewise pretty hardy. So who knows?
What we already know is interesting enough. As Carl Sagan famously observed, we are all made of star-stuff; the very stuff of Earth, its ecosystem and us was all forged in supernova explosions, millions or billions of years before Earth formed.
We are all children of the stars. That’s pretty thought-provoking in and of itself.