Irregular Moons Discovered Around Uranus
2.11.1997

Where did these two irregular moons of Uranus originate? Last week two previously undiscovered moons of the distant gas planet were confirmed, the first in irregular orbits. All fifteen previously known moons of Uranus are 'regular', circling near the planet's equator. Most of these were discovered by the passing Voyager 2 spacecraft in 1986.

Earthset from Orion
19.11.2024

Eight billion people are about to disappear in this snapshot from space taken on 2022 November 21. On the sixth day of the Artemis I mission, their home world is setting behind the Moon's bright edge as viewed by an external camera on the outbound Orion spacecraft.

Mars in the Loop
7.11.2018

This composite of images spaced some 5 to 9 days apart, from late April (bottom right) through November 5 (top left), traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky.

The Satellites that Surround Earth
14.07.2003

Thousands of satellites orbit the Earth. Costing billions of dollars, this swarm of high altitude robots is now vital to communication, orientation, and imaging both Earth and space. One common type of orbit is geostationary where a satellite will appear to hover above one point on Earth's equator.

APOD: 2025 October 10 Б 50 Light-years to 51 Pegasi
9.10.2025

It's only 50 light-years to 51 Pegasi. That star's position is indicated in this snapshot from August 2025, taken on a night with mostly brighter stars visible above the dome at Observatoire de Haute-Provence in France.

Mars: The View from HiRISE
10.04.2006

HiRISE - the High Resolution Imaging Science Experiment - rides on the Mars Reconnaissance Orbiter (MRO)spacecraft just arrived in Mars orbit on March 10. This sharp view of the martian surface from the HiRISE camera includes image data with a full resolution of about 2.5 meters per pixel - recorded from a range of 2,500 kilometers.

An Inner Neptune for 55 Cancri
1.09.2004

Is our Solar System unique? The discovery of a Neptune-mass planet in an sub-Mercury orbit around nearby Sun-like star 55 Cancri, announced yesterday along with the discovery of other similar systems, gives a new indication that planetary systems as complex as our own Solar System likely exist elsewhere.

Apollo 17 s Moonship
26.12.2025

Awkward and angular looking, Apollo 17's lunar module Challenger was designed for flight in the near vacuum of space. Digitally enhanced and reprocessed, this picture taken from Apollo 17's command module America shows Challenger's ascent stage in lunar orbit.

Kepler Orrery IV
4.12.2015

The exoplanet hunting Kepler mission's total for candidate and confirmed multiple planet systems stands at 1,705 worlds in orbit around 685 distant stars. Put all of those exoplanet orbits on the same scale and follow their relative orbital motions to get Kepler Orrery IV.

APOD: 2025 November 3 Б A Double Helix Lunar Eclipse
2.11.2025

The image was timed to capture a total lunar eclipse -- but it came with quite a twist. First, the eclipse: the fully Earth-shadowed Moon is visible as the orange orb near the top.