Airglow, Gegenschein, and Milky Way
20.04.2013

As far as the eye could see, it was a dark night at Las Campanas Observatory in the southern Atacama desert of Chile. But near local midnight on April 11, this mosaic of 3 minute long exposures revealed a green, unusually intense, atmospheric airglow stretching over thin clouds.

Contrasting Terrains on Comet Churyumov Gerasimenko
19.08.2014

Where should Philae land? As ESA's robotic spacecraft Rosetta circles toward Comet 67P/ Churyumov-Gerasimenko, a decision must eventually be made as to where its mechanical lander should attempt to touch-down. Reaching the comet...

Big Dipper Above and Below Chilean Volcanoes
9.05.2017

Do you see it? This common question frequently precedes the rediscovery of one of the most commonly recognized configurations of stars on the northern sky: the Big Dipper. This grouping of stars is one of the few things that has likely been seen, and will be seen, by every generation.

Abell 3827: Cannibal Cluster Gravitational Lens
23.08.2021

Is that one galaxy or three? Toward the right of the featured Hubble image of the massive galaxy cluster Abell 3827 is what appears to be a most unusual galaxy -- curved and with three centers.

APOD: 2024 March 3 Б A Total Solar Eclipse Close Up in Real Time
3.03.2024

How would you feel if the Sun disappeared? Many eclipse watchers across the USA surprised themselves in 2017 with the awe that they felt and the exclamations that they made as the Sun momentarily disappeared behind the Moon.

A Flight through the Hubble Ultra Deep Field
27.08.2013

What would it look like to fly through the distant universe? To find out, a team of astronomers estimated the relative distances to over 5,000 galaxies in one of the most distant fields of galaxies ever imaged: the Hubble Ultra Deep Field (HUDF).

X Ray Superbubbles in Galaxy NGC 3079
5.03.2019

What created these huge galactic superbubbles? Two of these unusual bubbles, each spanning thousands of light-years, were recently discovered near the center of spiral galaxy NGC 3079. The superbubbles, shown in purple on the image right, are so hot they emit X-rays detected by NASA's Earth-orbiting Chandra X-Ray Observatory.

Quadrantids over the Great Wall
3.01.2020

Named for a forgotten constellation, the Quadrantid Meteor Shower is an annual event for planet Earth's northern hemisphere skygazers The shower's radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That location is not far from the Big Dipper, at the boundaries of the modern constellations Bootes and Draco.

APOD: 2024 May 8 Б Visualization: A Black Hole Accretion Disk
8.05.2024

What would it look like to circle a black hole? If the black hole was surrounded by a swirling disk of glowing and accreting gas, then the great gravity of the black hole would deflect light emitted by the disk to make it look very unusual. The featured animated video gives a visualization.

APOD: 2026 June 4 Б A Planetary Nebula with Cosmic Buckyballs
4.06.2026

What is happening inside this unusual nebula? Planetary nebula Tc 1, captured here in exquisite detail by the James Webb Space Telescope, is the celestial site where buckyballs were first identified in 2010. Buckminsterfullerene...