The Double Haze above Titan
10.08.2004

Most moons have no haze layer at all - why does Titan have two? Images from the Cassini spacecraft that slipped into orbit around Saturn last month confirm that the Solar System's most mysterious moon is surrounded not only by a thick atmosphere but also by two distinct spheres of haze.

Io in True Color
30.03.2014

The strangest moon in the Solar System is bright yellow. This picture, an attempt to show how Io would appear in the "true colors" perceptible to the average human eye, was taken in 1999 July by the Galileo spacecraft that orbited Jupiter from 1995 to 2003.

Retrograde Mars
27.10.2014

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

APOD: 2024 November 27 Б The Meteor and the Comet
27.11.2024

How different are these two streaks? The streak on the upper right is Comet Tsuchinshan-Atlas showing an impressive dust tail. The comet is a large and dirty iceberg that entered the inner Solar System and is shedding gas and dust as it is warmed by the Sun's light.

APOD: 2026 January 20 Б Io in True Color
20.01.2026

The strangest moon in the Solar System is bright yellow. The featured picture, an attempt to show how Io would appear in the "true colors" perceptible to the average human eye, was taken in 1999 July by the Galileo spacecraft that orbited Jupiter from 1995 to 2003.

A Wind From The Sun
18.03.2000

A wind from the Sun blows through our Solar System. The behaviour of comet tails as they flapped and waved in this interplanetary breeze gave astronomers the first hint of its existence. Streaming outward at 250-400 miles/second, electrons and ions boiling off the Sun's incredibly hot

An Ion Drive for Deep Space 1
26.10.1998

Space travel entered the age of the ion drive Saturday with the launch of Deep Space 1, a NASA mission designed primarily to test new technologies. Deep Space 1 is bound for asteroid 1992 KD in July 1999.

Searching for Meteorites in Antarctica
26.12.2002

Where is the best place on Earth to find meteorites? Although meteors fall all over the world, they usually just sink to the bottom of an ocean, are buried by shifting terrain, or are easily confused with terrestrial rocks.

Hen 1357: New Born Nebula
3.04.1998

This Hubble Space Telescope picture shows Hen-1357, the youngest known planetary nebula. Graceful, gentle curves and symmetry suggest its popular name - The Stingray Nebula. Observations in the 1970s detected no nebular material, but this image from March 1996 clearly shows the Stingray's emerging bubbles and rings of shocked and ionized gas.

Retrograde Mars
16.12.2003

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.