Three Tails of Comet NEOWISE
8.03.2021

What created the unusual red tail in Comet NEOWISE? Sodium. A spectacular sight back in the summer of 2020, Comet NEOWISE, at times, displayed something more than just a surprisingly striated white dust tail and a pleasingly patchy blue ion tail.

Deep Field: Nebulae of Sagittarius
21.05.2019

These three bright nebulae are often featured on telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula just left of center, and colorful M20 on the top left.

APOD: 2024 July 8 Б Exoplanet Zoo: Other Stars
8.07.2024

Do other stars have planets like our Sun? Surely they do, and evidence includes slight star wobbles created by the gravity of orbiting exoplanets and slight star dimmings caused by orbiting planets moving in front.

Venus Unveiled
30.03.2002

The surface of Venus is perpetually covered by a veil of thick clouds and remains hidden from even the powerful telescopic eyes of earth-bound astronomers. But in the early 1990s, using imaging radar...

The Mineral Moon
29.08.2003

Even if the Moon really were made of green cheese it probably wouldn't look this bizarre. Still, this mosaic of 53 images was recorded by the Jupiter-bound Galileo spacecraft as it passed near our own large natural satellite in 1992.

A Sagittarius Triplet
10.08.2015

These three bright nebulae are often featured in telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula left of center, and colorful M20 on the right.

NGC 6334: The Cats Paw Nebula
18.06.2014

Nebulas are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat's Paw Nebula visible in Scorpius.

APOD: 2023 April 19 Б Auroral Storm over Lapland
19.04.2023

On some nights the sky is the best show in town. On this night, auroras ruled the sky, and the geomagnetic storm that created this colorful sky show originated from an increasingly active Sun.

Superbubbles in the LMC
3.07.1996

Why is there a hole in the center of this nebula? A leading explanation is that it is caused by the stellar winds from the stars that live there. Stars - including the Sun - expel electrons, protons, and other charged ions in a steady stream - the stellar wind.

North Celestial Aurora
18.05.2024

Graceful star trail arcs reflect planet Earth's daily rotation in this colorful night skyscape. To create the timelapse composite, on May 12 consecutive exposures were recorded with a camera fixed to a tripod on the shores of the Ashokan Reservoir, in the Catskills region of New York, USA.