Stickney Crater
7.11.2009

Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877.

The Eskimo Nebula from Hubble and Chandra
30.07.2013

In 1787, astronomer William Herschel discovered the Eskimo Nebula. From the ground, NGC 2392 resembles a person's head surrounded by a parka hood. In 2000, the Hubble Space Telescope imaged the Eskimo Nebula in visible light, while the nebula was imaged in X-rays by the Chandra X-ray Observatory in 2007.

NGC 6369: The Little Ghost Nebula
28.10.2017

Wraithlike NGC 6369 is a faint apparition in night skies popularly known as the Little Ghost Nebula. It was discovered by 18th century astronomer Sir William Herschel as he used a telescope to explore the medicinal constellation Ophiucus. Herschel historically classified the round and planet-shaped nebula as a Planetary Nebula.

Julius Caesar and Leap Days
29.02.2020

In 46 BC Julius Caesar reformed the calendar system. Based on advice by astronomer Sosigenes of Alexandria, the Julian calendar included one leap day every four years to account for the fact that an Earth year is slightly more than 365 days long.

An Extreme Black Hole Outburst
11.03.2020

Astronomers believe they have now found the most powerful example of a black hole outburst yet seen in our Universe. The composite, false-color featured image is of a cluster of galaxies in the constellation of Ophiuchus, the serpent-bearer.

50 Light years to 51 Pegasi
9.10.2021

It's only 50 light-years to 51 Pegasi. That star's position is indicated in this snapshot from August, taken on a hazy night with mostly brighter stars visible above the dome at Observatoire de Haute-Provence in France.

The Gum Nebula over Snowy Mountains
27.06.2022

The Gum Nebula is so large and close it is actually hard to see. This interstellar expanse of glowing hydrogen gas frequently evades notice because it spans 35 degrees -- over 70 full Moons -- while much of it is quite dim.

M33: The Triangulum Galaxy
3.11.2022

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.

HD 82943: Planet Swallower
18.05.2001

Stars like HD 82943 are main sequence G dwarf stars with temperatures and compositions similar to the Sun. Also like the Sun, HD 82943 is known to have at least two giant planets, but unlike gas giants in our solar system their orbits are not nearly circular and bring them closer to the parent star.

Giant Cluster Bends, Breaks Images
14.06.1998

What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. Cluster galaxies here appear yellow and -- together with the cluster's dark matter -- act as a gravitational lens.