Astronomers have found evidence for a possible planet candidate in the M51 ("Whirlpool") galaxy, representing what could be the first planet detected outside of the Milky Way. Chandra detected the temporary dimming of X-rays from a system where a massive star is in orbit around a neutron star or black hole (shown in the artist's illustration). This dimming is interpreted as being a planet that passed in front of an X-ray source around the neutron star or black hole.

A composite image of M51 with X-rays from Chandra and optical light from NASA's Hubble Space Telescope contains a box that marks the location of the possible planet candidate.

This light curve shows how X-rays from M51-ULS-1 temporarily decrease to zero during the Chandra observations.

These 3D printable files of M51/Whirlpool galaxy were created by the Tactile Universe and edited by the Chandra team to add the location of the exoplanet candidate. Select the 3D printer of your choice to make your own 3D print of the M51 galaxy.