APOD: 2025 November 2 Б A Horseshoe Einstein Ring from Hubble
2.11.2025

What's large and blue and can wrap itself around an entire galaxy? A gravitational lens mirage. Pictured here, the gravity of a massive elliptical galaxy (luminous red galaxy: LRG) has gravitationally distorted the light from a much more distant blue galaxy.

Jupiter, Io, and Shadow
7.12.2002

Pictured above is the innermost of Jupiter's Galilean satellites, Io, superposed in front of the gas giant planet. To the left of Io is a dark spot that is Io's own shadow. A solar eclipse would be seen from within the shadow spot on Jupiter.

The Face on Mars
22.07.1995

This image, showing what looks to be a human face sculpted on the martian surface, was produced using data from NASA's Viking 1 orbiter in 1976. Described in a press release...

The Einstein Cross Gravitational Lens
27.03.2005

Most galaxies have a single nucleus -- does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar.

A Picturesque Venus Transit
23.06.2004

The rare transit of Venus across the face of the Sun earlier this month was one of the better-photographed events in sky history. Both scientific and artistic images have been flooding in from the areas that could see the transit: Europe and much of Asia, Africa, and North America.

Dark Sand Cascades on Mars
19.01.2010

They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars.

62 Kilometers above Comet Churyumov Gerasimenko
15.09.2014

Spacecraft Rosetta continues to approach, circle, and map Comet Churyumov-Gerasimenko. Crossing the inner Solar System for ten years to reach the vicinity of the comet last month, the robotic spacecraft continues to image the unusual double-lobed comet nucleus. The reconstructed-color image featured, taken about 10 days ago, indicates how dark this comet nucleus is.

Colors: Ring Nebula versus Stars
21.07.2021

What if you could see, separately, all the colors of the Ring? And of the surrounding stars? There's technology for that. The featured image shows the Ring Nebula (M57) and nearby stars through such technology: in this case, a prism-like diffraction grating.

NGC 281: Starless with Stars
19.11.2021

In visible light the stars have been removed from this narrow-band image of NGC 281, a star forming region some 10,000 light-years away toward the constellation Cassiopeia. Stars were digitally added back to the resulting starless image though.

I Brought You the Moon
1.04.2018

I love you so much that I brought you the Moon. Please take it before this tree becomes more interested. Also the Moon is heavier than I thought. And I foolishly picked it up by the hot side by mistake. But it is for you and, well, the others reading this APOD.