Eros From Orbit
15.02.2000

On February 14th, the NEAR spacecraft became the first artificial moon of an asteroid. Captured by the gentle gravity of a 20 mile long slipper-shaped mountain of rock, NEAR recorded this premier image while orbiting asteroid 433 Eros at a distance of about 200 miles.

APOD: 2023 June 30 Б Orbits of Potentially Hazardous Asteroids
29.06.2023

Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth.

Satellites Collide in Low Earth Orbit
17.02.2009

How often do satellites collide? Although minuscule space debris may strike any satellite on occasion, the first known collision between time two full satellites occurred only last week. Even though thousands of satellites have been launched, the low collision rate is caused by the great vastness of space.

VB 10: A Large Planet Orbiting a Small Star
3.06.2009

Can a planet be as large as the star that it orbits? Recent observations have discovered that nearby Van Biesbroeck's star might have just such a large planet. Although VB 10 lies only...

Comet Halleys Nucleus: An Orbiting Iceberg
3.01.2010

What does a comet nucleus look like? Formed from the primordial stuff of the Solar System, comet nuclei were thought to resemble very dirty icebergs. But ground-based telescopes revealed only the surrounding cloud of gas and dust of active comets nearing the Sun, clearly resolving only the comet's coma, and the characteristic cometary tails.

Epimetheus and Janus: Interchangeable Moons of Saturn
1.11.2005

These two moons change places. Epimetheus and Janus, two small moons of Saturn, actually switch positions as they orbit their home planet. The orbital radii of the moons are strangely separated by less than the radii of the moons themselves: about 50 kilometers. One moon orbits Saturn well ahead of the other, at first.

Titan Beyond the Rings
1.11.2014

When orbiting Saturn, be sure to watch for breathtaking superpositions of moons and rings. One such picturesque vista was visible recently to the robot Cassini spacecraft now orbiting Saturn. In 2006 April, Cassini captured Saturn's A and F rings stretching in front of cloud-shrouded Titan.

A Martian Valley
23.07.1999

This tantalizing close-up detail of a network of martian valleys was recorded from orbit this April by Mars Global Surveyor's camera. Water may once have flowed here but now sand dunes stripe the windswept valley floor.

The Earth Also Rises
24.03.2000

The Lunar Orbiter 1 spacecraft was launched in 1966 to map the lunar surface in preparation for the Apollo moon landings. NASA's plucky robotic explorer performed its job well and pioneered this classic view of the Earth poised above the lunar horizon.

Geostationary Highway through Orion
15.01.2017

Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth and it will orbit once in 24 hours. Because that matches Earth's rotation period, it is known as a geosynchronous orbit.