An X Class Flare Region on the Sun
6.11.2007

Why does the Sun flare? Unpredictably, our Sun unleashes tremendous flares expelling hot gas into the Solar System that can affect satellites, astronauts, and power grids on Earth. This close up of an active region on the Sun that produced a powerful X-class flare was captured by the orbiting TRACE satellite.

APOD: 2026 May 15 Б R3 PanSTARRS: An Orion Comet
15.05.2026

Comet R3 PanSTARRS might be best remembered as an Orion comet. A key reason is because Comet C/2025 R3 (PanSTARRS) was near its most spectacular -- in terms of tail visibility -- when passing in front of the iconic constellation.

APOD: 2024 July 28 Б Sun Dance
28.07.2024

Sometimes, the surface of our Sun seems to dance. In the middle of 2012, for example, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressive prominence that seemed to perform a running dive roll like an acrobatic dancer.

Orion s Cradle
25.01.2007

Cradled in glowing hydrogen, stellar nurseries in Orion lie at the edge of a giant molecular cloud some 1,500 light-years away. This breath-taking view spans about 13 degrees across the center of the well-known constellation with the Great Orion Nebula, the closest large star forming region, just right of center.

Equinox and the Iron Sun
23.09.2010

Today, the Sun crosses the celestial equator heading south at 03:09 Universal Time. Known as an equinox, this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. Equinox means equal night.

Galileo's Europa
15.01.2022

Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon's icy surface likely hides a deep, global ocean. Galileo...

Galileo s Europa
20.05.2023

Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon's icy surface likely hides a deep, global ocean. Galileo...

APOD: 2024 January 31 Б Camera Orion Rising
31.01.2024

What does Orion rising look like to a camera? During this time of the year, the famous constellation is visible to the southeast just after sunset. From most Earthly locations, Orion's familiar star pattern, highlighted by the three-stars-in-a-row belt stars, rises sideways.

The Radio Sky: Tuned to 408MHz
26.11.1996

Tune your radio telescope to 408MHz (408 million cycles per second) and check out the Radio Sky! You should find that frequency on your dial somewhere between US broadcast television channels 13 and 14.

Rocket Fuel
16.11.2007

This gorgeous image of Orion shows off the constellation's young stars and cosmic clouds of hydrogen gas and dust. Made with a film camera tracking the stars on November 11, the exposure lasted some 40 minutes.