APOD: 2025 December 16 Б Andromeda and Sprites over Australia
16.12.2025

WhatБs happening over that tree? Two very different things. On the left is the Andromeda galaxy, an object that is older than humanity and will last billions of years into the future. Andromeda (M31) is similar in size and shape to our own Milky Way Galaxy.

Full Moonlight
3.01.2026

The Full Moon is the brightest lunar phase, and tonight you can stand in the light of the first Full Moon of 2026. In fact, the Moon's full phase occurs on January...

M82: Galaxy with a Supergalactic Wind
23.07.2019

Why is the Cigar Galaxy billowing red smoke? M82, as this starburst galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas and dust, however.

A Fisheye View of Comet Hale-Bopp
25.08.1997

Thousands of stars, several constellations, a planet and a comet all graced the western horizon over Ujue, Spain just after sunset on April 4th, 1997. Because the picture was taken with a fisheye lens, much of the whole night sky is visible. Comet Hale-Bopp, with both tails blazing, appears right of center.

Mount Sharp on the Horizon
8.03.2014

Get out your red/blue glasses (red for the left eye) and look out over this expansive martian landscape. The panoramic stereo view is composed of images from the roving Curiosity's Navcam taken at a rest stop during a 100 meter drive on Sol 548 (February 19).

The Moon During a Total Lunar Eclipse
25.05.2021

How does the Moon's appearance change during a total lunar eclipse? The featured time-lapse video was digitally processed to keep the Moon bright and centered during the 5-hour eclipse of 2018 January 31. At first the full moon is visible because only a full moon can undergo a lunar eclipse.

Compton Reentry
3.06.2000

Nine years ago the massive Compton Gamma Ray Observatory, the second of NASA's space-based great observatories, was deployed in low earth orbit. Lofted above the protective atmosphere, Compton's instruments could explore the extreme high-energy Universe in gamma rays -- photons with 100,000 times or more the energy of visible light.

APOD: 2023 August 2 Б M82: Galaxy with a Supergalactic Wind
2.08.2023

Why is the Cigar Galaxy billowing red smoke? M82, as this starburst galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas and dust, however.

Nebulosity in Sagittarius
18.07.1996

What causes the colors in this beautiful nebulosity in Sagittarius? Dubbed NGC 6589 and NGC 6590, the colors of this nebulosity, are caused by gas and dust. The blue color of the nebula nearest the bright stars is caused by reflection off interstellar dust.

Orion Star Colours
29.08.1998

What determines a star's colour? Its temperature. Red stars are cool, around 3,000 kelvins (K), while blue stars are hotter and can have temperatures over 30,000 K. Our own lovely yellow Sun's temperature is a comforting 6,000 K.