April 14 Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 14

Messier 96

Image Credit & Copyright: Mark Hanson and Mike Selby

Explanation: Spiral arms seem to swirl around the core of Messier 96 in this colorful, detailed portrait of a beautiful island universe. Of course M96 is a spiral galaxy, and counting the faint arms extending beyond the brighter central region it spans 100 thousand light-years or so. That’s about the size of our own Milky Way. M96 is known to be 38 million light-years distant, a dominant member of the Leo I galaxy group. Background galaxies and smaller Leo I group members can be found by examining the picture. The most intriguing one is itself a spiral galaxy seen nearly edge on behind the outer spiral arm near the 1 o’clock position from center. Its bright central bulge cut by its own dark dust clouds, the edge-on background spiral appears to be about 1/5 the size of M96. If that background galaxy is similar in actual size to M96, then it would be about 5 times farther away.

March 26 Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 March 26

Pluto at Night

Image Credit: NASAJohns Hopkins Univ./APLSouthwest Research Institute

Explanation: The night side of Pluto spans this shadowy scene. In the stunning spacebased perspective the Sun is 4.9 billion kilometers (almost 4.5 light-hours) behind the dim and distant world. It was captured by far flung New Horizons in July of 2015 when the spacecraft was at a range of some 21,000 kilometers from Pluto, about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto’s tenuous, surprisingly complex layers of hazy atmosphere. Near the top of the frame the crescent twilight landscape includes southern areas of nitrogen ice plains now formally known as Sputnik Planitia and rugged mountains of water-ice in the Norgay Montes.