Plains and Ridges on Europa
15.12.1998

The ridges on Europa may be caused by cold water volcanoes. Europa, one of the largest moons of Jupiter, has been the source of intense scrutiny since speculation increased of there being oceans beneath its icy surface.

Deploying Spartan
12.08.1999

Last October the Space Shuttle Discovery deployed Spartan 201, a spacecraft that monitored the corona of the Sun. Instruments on Spartan 201 were used to estimate the density of electrons emitted into the solar...

Looking Back Across Mars
25.05.2010

It's been a long trip for the Martian rover Opportunity. Last week Opportunity surpassed Viking 1 as the longest running mission on Mars, now extending well over six years. Pictured above, Opportunity's tire tracks cross a nearly featureless Martian desert, emanating from a distant horizon.

Valles Marineris: The Grand Canyon of Mars
27.03.2011

The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep.

Lunar Shadow Transit
11.03.2016

This snapshot from deep space captures planet Earth on March 9. The shadow of its large moon is falling on the planet's sunlit hemisphere. Tracking toward the east (left to right) across the ocean-covered world the moon shadow moved quickly in the direction of the planet's rotation.

Europa: Discover Life Under the Ice
1.04.2016

Looking for an interplanetary vacation destination? Consider a visit to Europa, one of the Solar System's most tantalizing moons. Ice-covered Europa follows an elliptical path in its 85 hour orbit around our ruling gas giant Jupiter.

APOD: 2023 December 24 Б NGC 2440: Cocoon of a New White Dwarf
24.12.2023

What's that in the center? Like a butterfly, a white dwarf star begins its life by casting off a cocoon of gas that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest cocoon of all.

Approaching Asteroid Eros
12.02.2001

Today, at about 3 pm EST, the first human-made spacecraft is scheduled to touchdown on an asteroid. At an impact speed of 8 kilometers per hour, it is most probable that the robot spacecraft NEAR-Shoemaker will not survive its planned collision with 433 Eros.

If You Could Stand on Mars
7.02.1996

If you could stand on Mars - what would you see? Viking 1 robot landers answered this question in 1976 with pictures like the one shown above. The dark rocks, red soil, and green-tinged sky grace this rendition of a normal Martian afternoon. At the bottom corners of the picture are portions of Viking spacecraft.

Oceans Under Jupiter's Europa?
9.04.1997

Is there life beneath Europa? Today, new results are being announced (at about 2 pm EST) about the possibility of oceans under Jupiter's moon Europa. The existence of such oceans increases the likelihood that some sort of life exists beneath the fractured ice planes of Jupiter's smoothest satellite.