Astronomers have discovered a new class of space objects called “dark comets” that could provide insights into the origins of Earth’s water. These objects, which may constitute up to 60% of all near-Earth objects, resemble asteroids with ice hidden beneath their surface. Unlike typical comets, dark comets lack a visible coma and tail but exhibit inexplicable acceleration, likely due to sublimating ice.
Researchers believe dark comets originate from the asteroid belt between Mars and Jupiter. Computer simulations traced their orbits back to the inner asteroid belt, supporting the theory that icy materials are prevalent in this region. This discovery strengthens the hypothesis that icy objects, such as dark comets, played a significant role in delivering water to Earth during its early formation.
The study also highlights “active asteroids,” which exhibit comet-like behavior within the asteroid belt, as potential contributors to Earth’s water. While the exact relationship between dark comets and active asteroids remains unclear, both types of objects are considered key players in the story of Earth’s water.
ead author Aster Taylor, a graduate student in astronomy at the University of Michigan, explains that the study offers a potential pathway for ice to travel from the outer solar system to near-Earth environments. Although it’s still debated how exactly Earth’s water originated, this research presents another possible mechanism for ice delivery.
Additionally, the study suggests that some large objects might come from the Jupiter family of comets, whose orbits bring them close to Jupiter.