Aurorae on Jupiter
11.07.2016

Jupiter has aurorae. Like Earth, the magnetic field of the gas giant funnels charged particles released from the Sun onto the poles. As these particles strike the atmosphere, electrons are temporarily knocked away from existing gas molecules. Electric force attracts these electrons back. As the electrons recombine to remake neutral molecules, auroral light is emitted.

Jupiter Near Opposition
22.10.2011

On October 29 (UT), Jupiter, the solar system's largest planet, will be at opposition, opposite the Sun in planet Earth's sky, shining brightly and rising as the Sun sets. That configuration results...

Dark Sun over Ternate
10.03.2016

A dark Sun hangs in the clearing sky over a volcanic planet in this morning sea and skycape. It was taken during this week's total solar eclipse, a dramatic snapshot from along the narrow path of totality in the dark shadow of a New Moon.

Parhelia at Abisko
15.02.2025

Three suns seem to hug the horizon in this otherworldly winterscape. But the evocative scene was captured during a February 3rd snowmobile exploration of the mountainous region around Abisko National Park, northern Sweden, planet Earth.

The Andromeda Galaxy in Ultraviolet
18.07.2021

What does the Andromeda galaxy look like in ultraviolet light? Young blue stars circling the galactic center dominate. A mere 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go.

The Edge of Space
24.07.2021

Where does space begin? For purposes of spaceflight some would say at the Karman line, currently defined as an altitude of 100 kilometers (60 miles). Others might place a line 80 kilometers (50 miles) above Earth's mean sea level.

APOD: 2025 November 16 Б Crossing Saturns Ring Plane
16.11.2025

If this is Saturn, where are the rings? When Saturn's "appendages" disappeared in 1612, Galileo did not understand why. Later that century, it became understood that Saturn's unusual protrusions were rings and that when the Earth crosses the ring plane, the edge-on rings will appear to disappear.

Little Planet Shadowrise
24.10.2013

Warm shades and subtle colors come to the sky in the fading sunlight after shadowrise on this little planet. Of course the little planet is planet Earth, and this nadir-to-zenith, around-the-horizon mosaic maps the view from a small airfield near the town of Intendente Alvear, La Pampa province, Argentina.

A Daytime Fireball Over South Wales
1.10.2003

Jon Burnett, a teenager from South Wales, UK, was photographing some friends skateboarding last week when the sky did something very strange. High in the distance, a sofa-sized rock came hurtling into the nearby atmosphere of planet Earth and disintegrated.

Extrasolar Super Earth Gliese 1214b Might Hold Water
10.09.2013

Might this distant planet hold water? Actually, given how close Gliese 1214b is to its parent star, any water, if it exists, would surely be in the form of steam. In the above artist...