Galactic Collisions

NASA Sheds New Light On Dark Matter

A recent research conducted by NASA has shed new light on Dark Matter, which makes up more than 80% of our Universe. The research has concluded that dark matter doesn’t interact with one another. The idea of the presence of dark matter first came into being when it was found that the visible universe did not account for the complete matter that should be between hundreds of billions of Galaxies out there.

According to leading researchers, if there was no Dark Matter, then all the Galaxies in the universe would be tearing themselves apart. The name ‘Dark Matter’ was given by scientists because it doesn’t absorb, reflect or emit light. However, it’s gravitational effect can be seen on light which somewhat bends light. This effect is known as lensing effect. For years, scientists have used this phenomenon to study dark matter.

Galactic Collisions
Galactic Collision

For the new study, scientists and researchers looked at collisions of Galaxy clusters (72, in fact) to closely monitor how dark matter reacts in such cases. Galactic collisions are very common throughout the universe. Each collision may take hundreds of millions of years. People might think with hundreds of billions of stars in each galaxy, they are bound to collide when a collision occurs. But that’s not actually the case. The space between each star is so large that they rarely collide. For example, the nearest star to our Sun, Proxima Centauri is 4.3 light years away.

What can happen in the event of Galactic collisions, is the supermassive black holes that resides at the heart of the almost all galaxies, can merge and become bigger. The shape of the resultant galaxy can also change. For example, two elliptical galaxies can merge to form a spiral galaxy. This so happens, because during a collision both of the galaxies go into a gravitational spin and the stars realign themselves.

NASA image
This collage shows NASA/ESA Hubble Space Telescope images of six different galaxy clusters. The clusters were observed in a study of how dark matter in clusters of galaxies behaves when the clusters collide. 72 large cluster collisions were studied in total. Using visible-light images from Hubble, the team was able to map the post-collision distribution of stars and also of the dark matter (coloured in blue). The clusters shown here are, from left to right and top to bottom: MACS J0416.1–2403, MACS J0152.5-2852, MACS J0717.5+3745, Abell 370, Abell 2744 and ZwCl 1358+62. Image credit: NASA, ESA, D. Harvey (EPFL, Switzerland), R. Massey (Durham University, UK), the Hubble SM4 ERO Team, ST-ECF, ESO, D. Coe (STScI), J. Merten (Heidelberg/Bologna), HST Frontier Fields, Harald Ebeling(University of Hawaii at Manoa), Jean-Paul Kneib (LAM)and Johan Richard (Caltech, USA)

In the new study, scientists looked at 72 galaxy clusters, to study the effects when they collide. What they found was astonishing. During the collision, the Dark Matter didn’t interact with one another. In normal cases, matters collide and create a dragging effect. However, in case of dark matter, there were no such effects. So, the conclusion is that dark matter is not like any matter we know. In such cases, dark matter should slow down, but it didn’t.

In the last few years, physics as a career path has become very popular. Astrophysics is now very popular among students. If you want to pursue physics as a career, the best thing to do would be to do a B.Sc on Physics. In India, almost all the universities provide B.Sc. on Physics. A viable choice would be Kerala University. It’s one of the most well known universities in India. If you want to know more about Kerala University, you can check out Collegedunia, where you can provide detailed information about it.

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Lahaul Seth
A programmer and a web developer, he is the founder of Lion Blogger. His main hobbies are web design & development and providing writing services to clients.