Hubble View of a Galaxy Resembling an Atomic Nucleus

The spiral galaxy NGC 7252 has a superficial resemblance to an atomic nucleus surrounded by the loops of electronic orbits, and was informally dubbed the "Atoms for Peace" galaxy. These loops are well visible in a wider field of view image.

This nickname is quite ironic, as the galaxy’s past was anything but peaceful. Its peculiar appearance is the result of a collision between two galaxies that took place about a billion years ago, which ripped both galaxies apart. The loop-like outer structures, likely made up of dust and stars flung outwards by the crash, but recalling orbiting electrons in an atom, are partly responsible for the galaxy’s nickname.

This NASA/ESA Hubble Space Telescope image shows the inner parts of the galaxy, revealing a pinwheel-shaped disk that is rotating in a direction opposite to the rest of the galaxy. This disk resembles a spiral galaxy like our own galaxy, the Milky Way, but is only about 10,000 light-years across — about a tenth of the size of the Milky Way. It is believed that this whirling structure is a remnant of the galactic collision. It will most likely have vanished in a few billion years’ time, when NGC 7252 will have completed its merging process.

Text credit: European Space Agency