Scientists from Colombia have discovered a trove of interred comets in an unexpected spot, the Los Angeles Times reported.
The comets were all named "Lazarus" for the way they appear to come back to life. The new discovery could be a long-uncovered group of the icy space rocks and could also help scientists understand their origins.
Long referred to as "falling stars," comets, typically a few kilometers across, travel around the sun as trapped water from the ice in them creates their signature tail of gas and dust.
Comets are thought to originate on the edge of the planetary system and have extremely stretched and oval-shaped orbit patterns around the sun. The trips are also believed to be only once every several thousand years. Shorter trips, only lasting a hundred centuries or so, are known to be similar to such sightings as Haley's Comet.
Recently, astronomers have found objects apparently similar to comets where they had not expected to find them - among a wide ring of asteroids between Mars and Jupiter.
"The surprising property of these objects is that their orbits are entirely asteroidal while their behavior is entirely cometary," the researchers wrote.
Comets are not supposed to exist amidst a planetary line, as the main belt is filled with debris several feet to hundreds of miles long. If not for the gravitational pull of the planets, those fragments floating about could have become the building blocks of a planet.
Those comets in the main belt may have once been a large population, the researchers from the University of Antioquia in Colombia said, but they had since died out.
Unknown to the researchers, the comets were lying dormant and were awoken as they made their way back towards orbiting the sun.
"Thus, we propose that the asteroidal belt contains an enormous graveyard of ancient dormant and extinct rocky comets, that turn on [are rejuvenated], in response to a diminution of their perihelion distance, caused by planetary perturbations."
The scientists discovered about a dozen of these Lazarus comets over the past decades and believe there are many more in existence.
