As much as we tend to panic over the idea of an asteroid crashing into the Earth, one possible explanation for life on Earth is that an asteroid brought it here in the first place.
In that sense, asteroids can serve as sort of “time capsule” into what molecular compounds were present on Earth way back when, as Hud recently explained at annual meeting of the American Association for the Advancement of Science in Austin, Texas last week.
Finding certain molecules in asteroids can often become a big deal, as this is one of the strongest pieces of evidence that those compounds were present in the early solar system when the foundations for life on Earth were generating. And the compounds found in Earth (and in living things) today definitely aren’t the same as the ones found 3.5 to 3.8 billions of years ago, when the first living cells formed.
Much like life, these molecules were initially simple and have evolved over time. According to Hud, who said the following in a press release:
Of course, there seem to be an endless amount of factors that influenced the formation of life, and other variables like the early existence of islands (which could serve as incubation chambers for early life) and some differences in our sun (which used to produce less light and more cosmic rays) could have influenced these as well.
But molecules, being fairly literal building blocks of life, are a key thing to consider, and asteroids can often hide a time capsule full of those early molecules that are crucial for examining.