Red Crepuscular Rays from an Eclipse
29.05.2022

What's happening behind that island? Things both expected and unexpected. Expected, perhaps, the pictured rays of light -- called crepuscular rays -- originate from the Sun. Unexpected, though, the Sun was being partially eclipsed by the Moon at the time -- late last month.

Solar Neutrino Astronomy
17.05.2001

Neutrinos are subatomic particles generated by the nuclear reactions which power stars like our Sun. Flying outward from the Sun's core, they easily pass through the Sun (and almost anything else!) unimpeded and should be detectable by earth-based neutrino "telescopes".

A Solar Prominence Eruption from SDO
6.03.2011

One of the most spectacular solar sights is an erupting prominence. Two weeks ago, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressively large prominence erupting from the surface. The dramatic explosion...

Blue Flash
8.01.2002

Difficult to observe, the momentary green flash above the rising or setting sun has been documented as a phenomenon caused by the atmospheric bending or refraction of sunlight. Like a weak prism, the Earth's atmosphere breaks white sunlight into colors, bending red colors slightly and green and blue colors through increasingly larger angles.

Anticrepuscular Rays over Sicily
24.06.2026

The Sun has just set... in the opposite side of the sky. Pictured here are anticrepuscular rays apparently converging in the east in this image of the limestone plateau in the heart of the Hyblaean Mountains of southeastern Sicily, in Italy. How were these anticrepuscular rays formed, if the Sun wasn't there?

A Solar Prominence Erupts in STEREO
20.10.2009

What does a solar prominence look like in three dimensions? To help find out, NASA launched the STEREO satellites to keep a steady eye on the Sun from two different vantage points. The STEREO...

APOD: 2023 December 11 Б Solar Minimum versus Solar Maximum
10.12.2023

The surface of our Sun is constantly changing. Some years it is quiet, showing relatively few sunspots and active regions. Other years it is churning, showing many sunspots and throwing frequent Coronal Mass Ejections (CMEs) and flares.

Moon Games
1.08.2008

The Moon's measured diameter is around 3,476 kilometers (2,160 miles). But apparent angular size, or the angle covered by an object, can also be important to Moon enthusiasts. Angular size depends on distance, the farther away an object is, the smaller an angle it covers.

Video: Comet Leonard over One Hour
24.01.2022

Which direction is this comet heading? Judging by the tail, one might imagine that Comet Leonard is traveling towards the bottom right, but a full 3D analysis shows it traveling almost directly away from the camera.

Anticrepuscular Rays Over Wyoming
21.02.2012

What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Pictured above are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds.