Unusual Layers on Saturns Moon Phoebe
14.06.2004

What caused the unusual light and dark layers on Saturn's moon Phoebe? The layers were discovered just Friday during the Cassini spacecraft flyby of the small moon. Such layering is particularly evident on the crater just above the image center, where alternating light and dark material makes this crater appear particularly structured.

Saturns Moon Tethys from Cassini
29.11.2004

Tethys is one of the larger and closer moons of Saturn. The Cassini spacecraft now orbiting Saturn passed near the frozen moon at the end of October, capturing the most detailed images since the Voyager spacecrafts in the early 1980s.

Fifth Moon Discovered Orbiting Pluto
16.07.2012

A fifth moon has been discovered orbiting Pluto. The moon was discovered earlier this month in images taken by the Hubble Space Telescope in preparation for the New Horizons mission's scheduled flyby of Pluto in 2015.

Uranus' Ring System
30.04.1996

The rings of Uranus are thin, narrow, and dark compared to other planetary ring systems. Brightened artificially by computer, the ring particles reflect as little light as charcoal, although they are really made of ice chucks darkened by rock.

Contrail Clutter over Georgia
13.10.2004

Artificial clouds made by humans may become so common they change the Earth's climate. The long thin cloud streaks that dominate the above satellite photograph of Georgia are contrails, cirrus clouds created by airplanes. The exhaust of an airplane engine can create a contrail by saturating the surrounding air with extra moisture.

A Year of Extraterrestrial Fountains and Flows
31.12.2006

The past year was extraordinary for the discovery of extraterrestrial fountains and flows -- some offering new potential in the search for liquid water and the origin of life beyond planet Earth.. Increased evidence was uncovered that fountains spurt not only from Saturn's moon Enceladus, but from the dunes of Mars as well.

Leonid Meteor Shower Next Week
8.11.1998

Early next week, a spectacular meteor storm is expected: the 1998 Leonids. It is widely thought that that the meteors from the Leonids meteor shower are just small pieces of Comet Temple-Tuttle falling to Earth.

Mimas: Small Moon with a Big Crater
17.05.2009

Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn's smallest moons. The crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is pictured above.

Triton: Neptune's Largest Moon
10.10.1996

Today marks the 150^th anniversary of the discovery of Triton. On October 10 1846, William Lassell was observing the newly discovered planet Neptune. He was attempting to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune had a satellite as well.

APOD: 2024 April 23 Б Contrail Shadow X
23.04.2024

What created this giant X in the clouds? It was the shadow of contrails illuminated from below. When airplanes fly, humid engine exhaust may form water droplets that might freeze in Earth's cold upper atmosphere. These persistent streams of water and ice scatter light from the Sun above and so appear bright from below.