Comets are leftovers of stars and planets that used to exist somewhere around 4.6 billion years prior.
In the era of dinosaurs, there were no instruments and devices available that could analyse the threat beforehand and find measures to deal with it.
Zapping simulated space ice with imitation starlight makes the ice act more like a liquid than a solid, meaning similar ices in space might be good places for organic chemistry.
Every human has always wondered what lies beneath and beyond the sky. One always tends to try and put meaning to the universe that lies around him. And thus, astronomy came into being.
The solar system comprises of a star and all the objects that travel around it- moons, planets, comets, asteroids, meteoroids etc. Solar systems can have more than one star called as binary star systems; with more than two stars they are known as multi-star systems.
Our Solar system consists of the stars, the Sun, and all the planets that orbit around it including the Earth. It also includes numerous moons, asteroids, comets, rocks and dust. The Sun is simply one star amongst the hundreds of billions of the stars present in the Milky Way Galaxy.