The Atoms for Peace

NGC 7252, the Atoms for Peace Galaxy. Image: NASA/ESA.
NGC 7252, the Atoms for Peace Galaxy. Image: NASA/ESA.

Some 220 million light years away lies this wreckage of a billion-year old cosmic collision, formed from two galaxies that crashed into one another and merged.

The newly-combined galaxy is known as NGC 7252 and, if you look closely at this Hubble Space Telescope image, you can see what appears to be a small spiral galaxy nestled within the midst of complex rings and loops of stars and gas thrown about by the merger. This small spiral, just 10,000 light years across and rotating in the opposite direction, is believed to be the remnant of one of the galaxies that took part in the collision. You may also notice that the centre of the galaxy has a bluish tint to it, the result of hundreds of hot, young and extremely massive ultra-luminous stars, formed in the aftermath of the collision as gravitational forces violently disturbed nascent nebulae. These blue stars come in clusters, including one, named W3, that is the most luminous star cluster known.

The loops of gas and dust and stars that encircle NGC 7252 look somewhat similar to the orbits of electrons around the nucleus of an atom. Perhaps better seen in wide-field images, NGC 7252’s appearance has earned it the nickname the ‘Atoms of Peace’ Galaxy, after a phrase coined by President of the United States Dwight Eisenhower in 1961, regarding using nuclear energy for peaceful purposes.

For amateur astronomers wishing to track down the Atoms of Peace for themselves, they can find the galaxy glowing dimly at magnitude +12.7 in the constellation of Aquarius.