Astronomy Picture of the Day

Explanation: What is going on with this galaxy?NGC 2685 is a confirmed polar ring galaxy - a rare type of galaxy withstars, gas and dust orbiting in rings perpendicular to the plane ofa flat galactic disk.The bizarre configuration could becaused by the chancecapture of material from another galaxy by a disk galaxy,with the captured debris strung out in a rotating ring.Still, observedproperties of NGC 2685suggest that the rotating helix structure is remarkably old and stable.In this sharp view of the peculiar system also known asArp336 or the Helix galaxy, the strange, perpendicular ringsare easy to trace as they pass in front of the galactic disk,along with other disturbed outer structures.NGC 2685 is about 50,000 light-years across and40 million light-years away in the constellation of the Great Bear (Ursa Major).