Odyssey at Mars
25.10.2001

After an interplanetary journey lasting 200 days, the Mars Odyssey spacecraft has entered orbit around the Red Planet. This latest success is welcome as in the past, Mars has often seemed a difficult planet to visit.

NGC 6302: Big Bright Bug Nebula
5.05.2004

The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects, and NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees...

Three Worlds for TRAPPIST 1
7.05.2016

Three new found worlds orbit the ultracool dwarf star TRAPPIST-1, a mere 40 light-years away. Their transits were first detected by the Belgian robotic TRAnsiting Planets and Planetesimals Small Telescope, TRAPPIST, at ESO's La Silla Observatory in Chile. The newly discovered exoplanets are all similar in size to Earth.

Close Up of Enceladus Tiger Stripes
31.03.2008

Could life exist beneath Enceladus? A recent flyby of Saturn's icy moon has bolstered this fascinating idea. Two years ago, images from the robotic Cassini spacecraft orbiting Saturn led astronomers to the undeniable...

The Deep Sky Toward Andromeda
8.09.2021

What surrounds the Andromeda galaxy? Out in space, Andromeda (M31) is closely surrounded by several small satellite galaxies, and further out it is part of the Local Group of Galaxies -- of which our Milky Way galaxy is also a member.

Sun Halo at Winter Solstice
14.01.2002

Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.

Cassini to Venus
3.07.2004

Saturn Orbiter Cassini with Titan Probe Huygens attached rocketed into early morning skies on October 15, 1997. The mighty Titan 4B Centaur rocket is seen here across the water, arcing away from Launch Complex 40 at Cape Canaveral Air Station.

Dry Ice Sled Streaks on Mars
17.06.2013

What creates these long and nearly straight grooves on Mars? Dubbed linear gullies, they appear on the sides of some sandy slopes during Martian spring, have nearly constant width, extend for as long as two kilometers, and have raised banks along their sides.

Crossing Dingo Gap on Mars
18.02.2014

An important threshold on Mars has now been crossed. Landing in mid-2012, the Curiosity rover is searching for clues of whether life could ever have existed on the red planet. Recent findings of Curiosity include evidence for an ancient (but now dried) freshwater lake, and the non-detection of the biomarker methane in the Martian atmosphere.

APOD: 2024 November 19 Б Undulatus Clouds over Las Campanas Observatory
19.11.2024

What's happening with these clouds? While it may seem that these long and thin clouds are pointing toward the top of a hill, and that maybe a world-famous observatory is located there, only part of that is true.