Astronomy Picture of the Day

Explanation: This popular group is famous as the Leo Triplet - a gathering of three magnificent galaxies in one field of view. Crowd pleasers when imaged with even modest telescopes, these galaxies can be introduced individually as NGC 3628 (top), M66 (bottom left), and M65 (bottom right). All three are large spiral galaxies. They tend to look dissimilar because their galactic disks are tilted at different angles to our line of sight. NGC 3628 is seen edge-on, with obscuring dust lanes cutting across the plane of the galaxy, while the disks of M66 and M65 are both inclined enough to show off their spiral structure. Gravitational interactions between galaxies in the group have also left telltale signs, including the warped and inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous deep view of the region spans about one degree (two full moons) on the sky. The field covers over 500 thousand light-years at the trio's estimated distance of 30 million light-years.