That day in Chelyabinsk in February 2013 reminded the world that the Earth does not exist in a bubble.
Asteroids provide a direct connection between the Earth and interplanetary space.
Craters such as theBarringer Crater in Arizonaare a stark reminder.
The dinosaurs died outdue to a different impactnot far away in the Gulf of Mexico.
But elsewhere in the universe, asteroidsmay actually transport life between different planets.
Heres why:
The Barringer Meteor Crater from 36,000 ft (11,000 m) in Arizona, USA.
Davezolis/Wikipedia, CC BY-SA
1.
They could kill us
We did not see the Chelyabinsk meteor coming until the Russian dashcams caught it.
Fortunately, nobody died as a direct result of the explosion.
Next time we may not be so lucky.
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NASAs Dawn space probe visited the largest known asteroid, Ceres, and detected water on its surface.
Ceres a one-time ocean world, according to NASA.
Nostalgia for Infinity/Shutterstock
3.
In this way, asteroids can act as time capsules for evidence of the ancient universe.
The star on the left shrinks and becomes the white dwarf in the middle of the image.
On the right is our own sun, for comparison.
RJHall/Wikipedia, CC BY-SA
5.
A large enough impact by an asteroid would impart enough energy to eject material from the planets surface.
TheTRAPPIST-1system is just one example.
Upon reaching its destination, it must survive entry to the new planet, including another surface impact.
The wide range of planetary systems discovered by astronomers in recent years could help.
Some of these are tightly packed with potentially habitable planets close together.
Themany hurdles involved in this interplanetary hopmake an arduous battle for microorganisms looking for a new home.
With each new world comes a greater understanding of the key role they play in shaping our universe.
