NGC 4651: The Umbrella Galaxy
2.07.2014

Spiral galaxy NGC 4651 is a mere 62 million light-years distant, toward the well-groomed northern constellation Coma Berenices. About the size of our Milky Way, this island universe is seen to have a faint umbrella-shaped structure that seems to extend (left) some 100 thousand light-years beyond the bright galactic disk.

Hale-Bopp in Stereo
4.04.1997

This stereo pair of Hale-Bopp images combines two pictures from slightly different viewing angles. Simulating stereo vision, the difference was generated by the comet's apparent motion as it cruised through the inner Solar System.

Retrograde Mars
13.06.2010

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Retrograde Mars
11.05.2008

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Retrograde Mars
27.10.2014

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Retrograde Mars
16.12.2003

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Comet PanSTARRS with Galaxy
6.06.2014

Sweeping slowly through northern skies, the comet PanSTARRS C/2012 K1 posed for this telescopic portrait on June 2nd in the constellation Ursa Major. Now in the inner solar system, the icy body from the Oort cloud sports two tails, a lighter broad dust tail and crooked ion tail extending below and right.

Debris Disks Surround Distant Suns
10.12.2004

In this dramatic artist's vision, debris along the outer reaches of a planet forming disk orbits in the glare of a distant sun. But inset are actual images of such disks around two nearby stars - AU Microscopii (top left; edge-on) and HD107146 (right: face-on) - as seen by the Hubble Space Telescope.

APOD: 2023 February 13 Б Comet ZTF and Mars
13.02.2023

No, Comet ZTF is not going to hit Mars. Nicknamed the Green Comet for its bright green coma, C/2022 E3 (ZTF) did, however, pass almost in front of the much-more distant planet a few days ago, very near in time to when the featured picture was taken.

Zodiacal Light
26.08.1997

Sometimes the sky itself seems to glow. Usually, this means you are seeing a cloud reflecting sunlight or moonlight. If the glow appears as a faint band of light running across the whole sky, you are probably seeing the combined light from the billions of stars that compose our Milky Way Galaxy.