A Double Ringed Basin on Mercury
7.10.2009

What created the internal second ring of this double ringed basin on Mercury? No one is sure. The unusual feature spans 160 kilometers and was imaged during the robotic MESSENGER spacecraft's swing past our Solar System's innermost planet last week.

The Vertical Magnetic Field of NGC 5775
27.01.2021

How far do magnetic fields extend up and out of spiral galaxies? For decades astronomers knew only that some spiral galaxies had magnetic fields. However, after NRAO's Very Large Array (VLA) radio telescope...

APOD: 2024 July 23 Б The Crab Nebula from Visible to X Ray
23.07.2024

What powers the Crab Nebula? A city-sized magnetized neutron star spinning around 30 times a second. Known as the Crab Pulsar, it is the bright spot in the center of the gaseous swirl at the nebula's core.

Phobos Over Mars
13.03.1999

Hurtling through space a mere 3,000 miles above the Martian surface, the diminutive moon Phobos (below and left of center) was imaged against the backdrop of a large shield volcano by the Viking 2 Orbiter in 1977.

ASCA X-Ray Observatory
20.02.1996

Today marks the third anniversary of the launch of the Advanced Satellite for Cosmology and Astrophysics (ASCA; renamed from Astro D when launched). ASCA, seen here superposed on galaxy M31, is a Japanese satellite for which NASA has provided some scientific equipment. ASCA carries four large-area X-ray telescopes.

The Frothy Milky Way
9.10.1999

Astronomers have discovered that looking at dust along the plane of our Milky Way Galaxy is a bit like looking into a frothy glass of beer. The dust between stars in our galaxy appears...

Infrared Saturn
24.07.1999

This delightfully detailed false color image of Saturn was earmarked to celebrate the 8th anniversary of the orbiting Hubble Space Telescope. The picture is a combination of three images taken in January 1998 and shows the lovely ringed planet in reflected infrared light.

White Rock Fingers on Mars
15.02.2016

What caused this unusual light rock formation on Mars? Intrigued by the possibility that they could be salt deposits left over as an ancient lakebed dried-up, detailed studies of these fingers now indicate a more mundane possibility: volcanic ash. Studying the exact color of the formation indicated the possible volcanic origin.

The Fornax Cluster of Galaxies
11.06.2016

Named for the southern constellation toward which most of its galaxies can be found, the Fornax Cluster is one of the closest clusters of galaxies. About 62 million light-years away, it is almost...

Lunar Orbiter Earthset
27.08.2016

August 10th was the 50th anniversary of the launch of Lunar Orbiter 1. It was the first of five Lunar Orbiters intended to photograph the Moon's surface to aid in the selection of future landing sites.