Saturn at Night
12.09.2006

This is what Saturn looks like at night. In contrast to the human-made lights that cause the nighttime side of Earth to glow faintly, Saturn's faint nighttime glow is primarily caused by sunlight reflecting off of its own majestic rings.

Phobos: Doomed Moon of Mars
14.04.2008

This moon is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These...

Geostationary Satellites Beyond the Alps
11.04.2012

Why don't those stars move? Stars in the sky will typically appear to rise and set as the Earth turns. Those far to the north or south will appear to circle the pole. If you look closely at the above time-lapse movie, however, there are points of light that appear stationary.

Apollo 14 Heads for Home
5.02.2021

Fifty years ago this Sunday (February 7, 1971), the crew of Apollo 14 left lunar orbit and headed for home. They watched this Earthrise from their command module Kittyhawk. With Earth's sunlit crescent just peeking over the lunar horizon, the cratered terrain in the foreground is along the lunar farside.

International Space Station in Transit
9.05.2003

A stunning telescopic image of the International Space Station crossing in front of an eight day old Moon, this picture was captured on April 11th. But while Wednesday's leisurely transit of Mercury across the Sun entertained observers all over the dayside of planet Earth, the audience for this lunar transit was more restricted.

Atlas 5 Rocket Launches to the Moon
22.06.2009

This rocket is headed for the Moon. Pictured above, a huge Altas V rocket roared off the launch pad last week to start NASA's first missions to Earth's Moon in 10 years. The rocket is carrying two robotic spacecraft.

Ringside with Titan and Dione
5.01.2012

Orbiting in the plane of Saturn's rings, Saturnian moons have a perpetual ringside view of the gorgeous gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective.

Jets from Comet Churyumov Gerasimenko
2.02.2015

Where do comet tails come from? Although it is common knowledge that comet tails and comas originate from comet nuclei, exactly how that happens is an active topic of research. One of the best...

APOD: 2023 April 16 Б M2 9: Wings of a Butterfly Nebula
16.04.2023

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured here, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.

M2 9: Wings of a Butterfly Nebula
6.01.2002

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.