A Tether in Space
7.01.2018

One of the greatest unrequited legends of outer space is the tether. Tethers, long strands of material, hold the promise of stabilizing satellites, generating electricity, and allowing easy transportation. Possibly the most ambitious vision of the space tether is the space elevator popularized by Arthur C.

NGC 3717: A Nearly Sideways Spiral Galaxy
12.11.2019

Some spiral galaxies are seen nearly sideways. Most bright stars in spiral galaxies swirl around the center in a disk, and seen from the side, this disk can be appear quite thin. Some spiral galaxies appear even thinner than NGC 3717, which is actually seen tilted just a bit.

Deimos Before Sunrise
24.05.2025

Deimos takes 30 hours and 18 minutes to complete one orbit around the Red Planet. That's a little more than one Martian day or sol which is about 24 hours and 40 minutes long, so Deimos drifts westward across the Martian sky.

In A Grand Canyon On Mars
12.02.1998

In a grand canyon on Mars, steep slopes fall away from a smooth plateau revealing striking layered rock formations. The canyon is part of the Valles Marineris, a 2,500 mile long system of canyons cutting across the Martian equator.

Southwest Mercury
13.09.1996

The planet Mercury resembles a moon. Mercury's old surface is heavily cratered like many moons. Mercury is larger than most moons but smaller than Jupiter's moon Ganymede and Saturn's moon Titan. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron.

Jupiter's Dry Spots
12.06.1997

Known for its spectacular images of Jupiter's moons, Io, Ganymede, Callisto, and Europa, the robot spacecraft Galileo has also aggressively explored the Jovian atmosphere. In December of 1995, Galileo's atmospheric probe descended into Jupiter's clouds and reported a surprising absence of water.

Barnacle Bill And Sojourner
8.07.1997

Deployed on a pop-up mast to its full height, the Sagan Memorial Station's IMP camera now stands about 5 feet above the surface of Ares Vallis - on Mars. This is one of the first images from its new vantage point, showing the rover Sojourner near a rock named Barnacle Bill.

The North Pole Of Mars
24.09.1998

The North Pole of Mars is capped by layers likely consisting of ice and dust deposited over millions of years. Imaged on September 12 - early Spring for Northern Mars - by the Mars Global Surveyor's camera, this synthesized wide-angle color view shows the rippled, eroded polar terrain covered with pinkish seasonal carbon dioxide frost.

Aurora and Orion
20.03.1999

Looking toward the south from low Earth orbit, the crew of the Space Shuttle Endeavor made this stunning time exposure of the Aurora Australis or southern lights in April of 1994. Aurora are visible at high northern latitudes as well, with the northern lights known as Aurora Borealis.

Despina, Moon of Neptune
3.09.2009

Despina is a tiny moon of Neptune. A mere 148 kilometers across, diminutive Despina was discovered in 1989, in images from the Voyager 2 spacecraft taken during its encounter with the solar system's most distant gas giant planet.