Discovery of a strange galaxy
The Hubble Telescope Image of the Week shows Arp 122, an exotic galaxy that actually consists of **two galaxies** NGC 6040, a tilted and twisted spiral galaxy, and LEDA 59642, a ringed spiral galaxy, in the middle of a collision. This exciting cosmic encounter is located at a very safe distance of about 570 million light-years from Earth. Peeking out from the corner is elliptical galaxy NGC 6041, a central member of the galaxy cluster in which Arp 122 resides, but otherwise not participating in this brutal merger.
Galactic collisions and mergers are hugely active and dramatic events, but they happen on a very slow time scale. For example, the Milky Way is on track to collide with its nearest galactic neighbor, the Andromeda Galaxy (M31), but these two galaxies have **four billion years** before they actually meet. The collision and merging process won't be quick either: it could take **hundreds of millions of years** to unfold. These collisions take a long time because of the enormous distances involved.
Galaxies are made up of stars, their solar systems, dust and gas. Therefore, in galactic collisions, these components may experience huge changes in the gravitational forces acting on them. Over time, this completely changes the structure of the two (or more) colliding galaxies, Sometimes it eventually results in a single merged galaxy.
This may be what resulted from the collision shown in this image. Galaxies resulting from mergers are thought to have a regular or elliptical structure, with the merging process disrupting more complex structures (such as those observed in spiral galaxies). It will be fascinating to see what Arp 122 will look like once this collision is complete. But this will not happen for a very long time
Source: websites