What do you feel when you look at the night sky? Especially if it is a clear night sky with no clouds and you are far from any city lights. You raise your head and see countless beautiful stars. Although we know that the stars are massive and swirling clouds of hot dust and gas, they look quite interesting away from Earth.
Millions of light years away it's not sobeautiful and soothing. It may be difficult to imagine, but a sufficiently large percentage of stars in the night sky are waiting or have already experienced a cosmic collision.
Although from our point of view on Earth the starsthey look fixed, in fact, they move quite quickly in space, and there is a very high chance that they will collide with another massive body. The Universe is a giant pool table. Collisions in space can happen environment of any bodies, whether it be a star, an asteroid, a comet or a planet. The result is very spectacular bursts of energy and matter.
What happens when the stars or even the galaxycollide? Are collisions in space rare events or happen quite often? Can the Earth or the Solar System suffer from a collision with an asteroid or a massive super galaxy? Let's see.
Collisions of stars and galaxies
Thanks to photos from space telescopes andcomputer models, astronomers can search and observe both galactic and stellar collisions. Initially it was thought that these clashes, or mergers, were quite rare, but studies of the 21st century showed that these events occur quite often. As experts understand more and more about the universe and its beginning, they come to the conclusion that the younger the universe was, the more often galactic collisions occurred. Since the universe was much smaller, the galaxies were located closer and very likely collided as they moved away from the Big Bang. Even our Milky Way galaxy contains debris from early collisions with massive bodies. Astronomers suggest that the Andromeda galaxy, our closest big neighbor, will face ours in the distant future.
Cosmic collision sounds perfectmaterial for an expensive Hollywood blockbuster, but in reality it looks much less exciting than it looks. Even though galaxies and stars move towards each other at a speed of hundreds of kilometers per hour, their fusion may take millions of years. Instead of exploding like massive bombs, cosmic collisions flow smoothly, like clouds of gas colliding. When two stellar objects meet, the massive gravity of each of them changes the shape of the other, pulling in the form of a drop. On April 24, 2008, for example, the Hubble Space Telescope captured the effects of a collision between two large galaxies. While one galaxy assumed the usual form of a ring, the neighboring galaxy stretched its tail.
Another common type of collision iscollision of neutron stars. Neutron stars are actually the corpses of older stars — when a star reaches the end of its life, it explodes, and the mass, equivalent to the mass of a whole sun, concentrates on an area the size of a city. If two such stars form in close proximity, they form a binary pair of stars that merge for hundreds of millions of years. The combined mass of dead stars is so large that the final merger forms a black hole in space. Although currently a known number of neutron pairs can be counted on the fingers of both hands, scientists assume that in fact there are much more such events and they happen once or twice a year.
How about space collisions on a much smaller scale, like an asteroid and a planet like Earth?
Asteroid collision and survival
How many times have we seen this in the movie: an asteroid rushes through space and threatens life on Earth, and the heroes need to think of a way to stop it and save the human race. But what if the characters do not pull out, and the asteroid still crashes into the Earth? Will living organisms be able to survive, or the damage from a collision will destroy all living things?
Fortunately, the chances of survival are much higher thanyou think. Many experts believe that dinosaurs were destroyed as a result of the fall of a giant asteroid several million years ago, but many species survived the catastrophe, and we finally made it to the top of the food chain.
Survive a global catastrophe on the surfaceEarth is one thing, but are there other options for a struggling life to scramble out after a destructive collision? In 2008, an international group of students from Germany, Russia, the USA and the UK published a study that tested the extraordinary ability of bacteria to survive after an asteroid collision. The study concluded that living organisms can not only be lifted into the earth’s atmosphere along with a suspension of dust and returned to the surface, but also be transmitted along with rock fragments to another planet like Mars.
The students admitted that the so-calledLithopanspermia, or the transfer of life forms from one planet to another through impact ejection of rocks, is extremely unlikely. Any microorganisms clinging to debris must not only survive the explosion, but also a long journey (from 1 to 20 million years) from one planet to another, the radiation of solar rays and re-entry into the atmosphere of another planet.
They also noted that, despite allobstacles, 40 Martian meteorites found on Earth, indicate that such trips may well have occurred earlier. The experiments also tested the most tenacious bacteria and microorganisms, and found out that they not only could easily endure the terrible conditions of the cosmos, but also wanted to spit on any kind of shaking, from radiation to elevated pressure.