The Secret of the Black Aurora
1.01.2002

What causes black aurora? These gaps in normal bright aurora are frequently recorded but rarely questioned. Recent research using data from four Cluster spacecraft orbiting the Earth has now likely found the secret: black auroras are actually anti-auroras.

Running Red Rings Around Jupiter
5.02.1997

Jupiter has rings, too. Unlike Saturn's bright rings which are composed of chunks of ice, Jupiter's rings are darker and appear to consist of fine particles of rock. The six pictures above...

Sunspot Group 1429 and the Distant Sun
19.03.2012

What's that on the Sun? Over the past two weeks, one of the most energetic sunspot regions of recent years crossed the face of the Sun. Active Region 1429, visible above...

APOD: 2024 November 12 Б NGC 6888: The Crescent Nebula
12.11.2024

How was the Crescent Nebula created? Looking like an emerging space cocoon, the Crescent Nebula, visible in the center of the featured image, was created by the brightest star in its center. A leading progenitor hypothesis has the Crescent Nebula beginning to form about 250,000 years ago.

At the Edge of the Crescent Nebula
2.08.2000

The Crescent Nebula is a rapidly expanding shell of gas surrounding a dying star. In this recently released image by the Hubble Space Telescope, a bright dynamic part of the nebula three light-years across is shown in representative color.

Europa: The Latest From Galileo
17.01.1997

Today, NASA revealed recent results from the Galileo Probe's December 19th flyby of Europa, Jupiter's ice-covered moon - including this close-up image of fractured and frozen terrrain. The highest resolution picture ever made...

Unusual Spires Found on Comet Wild 2
22.06.2004

How did unusual spires form on comet Wild 2? Close inspection of images taken of Comet Wild 2 by the passing Stardust spacecraft in January show numerous strange pinnacles as long as 100 meters long jutting off the surface. The pinnacles were unexpected - close-ups of other comets and asteroids show no such features.

Lunar Close Up
12.02.1999

Late last month, NASA's Lunar Prospector spacecraft moved in for a closer look at the Moon. Now entering an extended mission phase, controllers have reduced the altitude of this polar lunar orbiter from 100 kilometers to about 30 kilometers (18 miles).

An Unusual Hole in Mars
12.06.2017

What created this unusual hole in Mars? Actually, there are numerous holes pictured in this Swiss cheese-like landscape, with all-but-one of them showing a dusty, dark, Martian terrain beneath evaporating, light, carbon-dioxide ice. The most unusual hole is on the upper right, spans about 100-meters, and seems to punch through to a lower level.

APOD: 2024 September 16 Б Mercurys Vivaldi Crater from BepiColombo
16.09.2024

Why does this large crater on Mercury have two rings and a smooth floor? No one is sure. The unusual feature called Vivaldi Crater spans 215 kilometers and was imaged again in great detail by ESA's and JAXA's robotic BepiColombo spacecraft on a flyby earlier this month.