The study highlights role of dark comets and active asteroids in delivering water to Earth.
There is a new class of space objects known as "dark comets" that astronomers have discovered that may provide information on the origins of Earth's water. These enigmatic objects could account for as much as 60% of all near-Earth objects; they seem to be asteroids with ice hidden beneath their surface.
Dark comets are not blurry like regular comets' coma and tail. On the other hand, they show an inexplicable acceleration, suggesting the existence of unobserved emissions, most likely due to sublimating ice.
Researchers believe these dark comets originate from the asteroid belt between Mars and Jupiter. Through computer simulations, they were able to mimic the dark comets' orbits and trace them back to the inner part of the asteroid belt. This finding supports the long-held theory that icy materials are common within the asteroid belt.
The discovery of dark comets strengthens the possibility that icy objects delivered water to Earth early in its formation. This idea is further bolstered by the existence of "active asteroids"-objects t that display comet-like behaviour within the asteroid belt.
While the exact connection between dark comets and active asteroids remains unclear, both types of objects could be key players in the story of Earth's water. Future studies will likely shed more light on these intriguing celestial bodies.
The study also shows a potential pathway for delivering ice into the near-Earth solar system, Taylor says. How Earth got its water is a longstanding question.
"We don't know if these dark comets delivered water to Earth. We can't say that. But we can say that there is still debate over how exactly the Earth's water got here," Aster Taylor, a U-M graduate student in astronomy and lead author of the study, said. "The work we've done has shown that this is another pathway to get ice from somewhere in the rest of the solar system to the Earth's environment."
The research further suggests that one large object may come from the Jupiter family of comets, comets whose orbits take them close to the planet Jupiter. The team's results are published in the journal Icarus.