An asteroid type known as Centaurs could one day destroy life on Earth, or perhaps create a new life form altogether.
Centaurs are rocky bodies found in the solar system which follow the orbits of giant planets such as Jupiter and Neptune.
It is believed they originated from beyond the orbit of Neptune, and travelled inwards towards the star.
They rummaged around the solar system for millions of years, and were the responsible for Late Heavy Bombardment from about 3.8 billion years ago when asteroids rained down on Earth.
Now, researchers warn a similar fate could happen to our planet once again in the future which could destroy life as we know it.
Astrophysicist Rudolf Dvorak from the University of Vienna said: “Such events could have a direct impact of life by either destroying Earth, or creating conducive conditions (hydrothermal activity) for new life to form.”
Fellow astrophysicist from the same university, Mattia Galiazzo, said: “We also estimate the possible crater sizes. Centaurs can become also active comets, because of the presence of water on a good number of them, thus we also compute the approximate amount of water released to the Earth, which is comparable to the amount of water present on the Adriatic sea, now.
“We also found subregions of the Centaurs where the possible impactors originate from.”
The experts estimate the craters caused by the Centaurs could be hundreds of kilometres in diameter.
However, the presently known batch of Centaurs would likely cause a crater about 10 kilometres in diameter.
To put that into perspective, the Chicxulub crater – which resulted from the asteroid which wiped out the dinosaurs – is about 150 kilometres in diameter.
This would mean any currently known Centaur would likely not be able to destroy Earth, but this does not mean that they are not out there.
However, the research could help understand the early formation of the solar system, and how life came to be on our planet.
As the scientists state in the report published in the Monthly Notices of the Royal Astronomical Society, “Centaurs can bring water”.
Dr Galiazzo adds: “Our work also provides the framework for better understanding past events, and how they might had altered life on Earth and other terrestrial planets.”