Titan: Moon over Saturn
25.05.2018

Like Earth's moon, Saturn's largest moon Titan is locked in synchronous rotation. This mosiac of images recorded by the Cassini spacecraft in May of 2012 show's its anti-Saturn side, the side always facing away from the ringed gas giant.

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.

Interstellar Interloper 2I Borisov
17.10.2019

After the 2017 detecton of 1I/'Oumuamua, comet 2I/Borisov has become the second recognized interstellar interloper. Like 'Oumuamua, Borisov's measured hyperbolic trajectory and speed as it falls toward the Sun confirm that its origin is from beyond our Solar System.

Starlink Satellite Trails over Brazil
9.12.2019

What are those streaks over the horizon? New Starlink satellites reflecting sunlight. SpaceX launched 60 Starlink communication satellites in May and 60 more in November. These satellites and thousands more are planned by communications companies in the next few years that may make streaks like these relatively common.

In the Center of the Cats Eye Nebula
9.07.2022

Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat's Eye Nebula (NGC 6543), to be one of the most complex planetary nebulae known.

APOD: 2025 September 8 Б IRAS 04302: Butterfly Disk Planet Formation
7.09.2025

This butterfly can hatch planets. The nebula fanning out from the star IRAS 04302+2247 may look like the wings of a butterfly, while the vertical brown stripe down the center may look like the butterfly's body -- but together they indicate an active planet-forming system.

Dark Matter Map
14.08.2003

The total mass within giant galaxy cluster CL0025+1654, about 4.5 billion light-years away, produces a cosmic gravitational lens -- bending light as predicted by Einstein's theory of gravity and forming detectable images of even more distant background galaxies.

A Message from Earth
17.07.1997

What are these Earthlings trying to tell us? The above message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of the Arecibo Observatory - still the largest radio telescope in the world - a string of 1's and 0's representing the above diagram was sent.

Arp 81: 100 Million Years Later
10.12.2003

From planet Earth, we view this strongly interacting pair of galaxies, cataloged as Arp 81, as they were only about 100 million years after their mutual closest approach. The havoc wreaked by gravity during...

Mapping Mars
18.03.1999

This month, the Mars Global Surveyor (MGS) spacecraft began its primary mission to the red planet. Orbiting about once every two hours at an altitude of over 200 miles, instruments onboard MGS now regularly explore the Martian surface and atmosphere.