Nearly invisible “dark comets” may have been responsible for bringing much of the water found on Earth to our planet ages ago. However, they could also pose a very terrible threat to Earth, according to new research.
The study in question is currently accepted for publication in the journal Icarus and is available on the preprint server arXiv right now. These comets are often small and spin rapidly while they wander close to Earth. They typically migrate from other parts of our solar system.
While these dark comets are believed to have played a part in bringing water and other important components for life to Earth, scientists have also issued new warnings about how dangerous they could be to present and future humanity. That’s because these comets are exceptionally difficult to spot.
And, since they are so hard to spot, that means they can come very close to Earth without us realizing it—potentially even hitting Earth before we have a chance to do anything to stop it. The real kicker with these space rocks is that they behave both like asteroids and comets.
Dark comets don’t seem to show any signs of outgassing or the evaporation of volatile elements. However, they also don’t move in the usual perfect orbits we’re used to with larger, more traditional comets, either. Instead, they seem to show evidence of “nongravitational acceleration,” which suggests there may be some other force pushing them through their orbits.
To safeguard our planet from these mysterious and hard-to-spot objects, we’ll really need to study the rogue population of asteroids, comets, and other dark comets to try to come up with ways to detect them before it’s too late. Hopefully, we can even come up with ways to predict their future movements, giving us even more time to mount a defense like the D.A.R.T test.
