Dark Sand Cascades on Mars
25.11.2012

They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars.

Dark Sand Cascades on Mars
28.11.2015

They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars.

NGC 2261: Hubbles Variable Nebula
20.10.1999

What causes Hubble's Variable Nebula to vary? The unusual nebula pictured above changes its appearance noticeably in just a few weeks. Discovered over 200 years ago and subsequently cataloged as NGC 2661, the remarkable nebula is named for Edwin Hubble, who studied it earlier this century.

A Superior Conjunction Of Mercury
8.09.1999

In astronomical parlance, an interior planet is at superior conjunction when it is located on the opposite side of the Sun from Earth. Mercury, the solar system's innermost planet, zips past this point in its orbit today.

Dark Sand Cascades on Mars
18.01.2010

They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars.

Saturn at Night
25.11.2022

Saturn is still bright in planet Earth's night skies. Telescopic views of the distant gas giant and its beautiful rings often make it a star at star parties. But this stunning view of Saturn's rings and night side just isn't possible from telescopes closer to the Sun than the outer planet.

Crescent Europa
24.02.2002

Although the phase of this moon might appear familiar, the moon itself might not. In fact, this crescent shows part of Jupiter's moon Europa. The passing robot spacecraft Voyager 2 captured this image in 1979.

A Total Solar Eclipse Over China
5.08.2008

What's that black dot over the Sun? The Moon. This past weekend, the Sun went dark during the day as the Moon completely covered it. The total solar eclipse was visible over a thin swath of Earth extending from northern Canada to China.

Apollo 11 Landing Site Panorama
20.07.2018

Have you seen a panorama from another world lately? Assembled from high-resolution scans of the original film frames, this one sweeps across the magnificent desolation of the Apollo 11 landing site on the Moon's Sea of Tranquility.

APOD: 2023 October 29 Б A Partial Lunar Eclipse
28.10.2023

What's happened to the Moon? Within the last day, part of the Moon moved through the Earth's shadow. This happens about once or twice a year, but not every month since the Moon's orbit around the Earth is slightly tilted.