A Green Flash from the Sun
4.06.2014

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.

Solstice Sun In Soft X-rays
21.12.1998

The solstice occurs today at 8:56 PM Eastern Standard Time. At the solstice the sun reaches its most southerly position in the sky and winter begins for the Northern Hemisphere while summer starts South of the Equator.

The Sun in Three Dimensions
24.04.2007

What does the Sun look like in all three spatial dimensions? To find out, NASA launched two STEREO satellites to perceive three dimensions on the Sun much like two eyes allow humans to perceive three dimensions on the Earth.

Moon AND Sun
7.09.2001

Today's composite image was made from 22 separate pictures of the Moon and Sun all taken from Chisamba, Zambia during the total phase of the 2001 June 21 solar eclipse. The multiple exposures...

The Sun Puffs
29.10.2006

Our Earth endures bursts of particles from the Sun. On 1997 April 7, at 10 am (EDT), ground monitors of the SOHO spacecraft, which continually monitors the Sun, noticed a weak spot in the solar corona was buckling again, this time letting loose a large, explosive Coronal Mass Ejection (CME).

Mercurys Transit: An Unusual Spot on the Sun
24.08.2014

What's that dot on the Sun? If you look closely, it is almost perfectly round. The dot is the result of an unusual type of solar eclipse that occurred in 2006. Usually it is the Earth's Moon that eclipses the Sun. This time, the planet Mercury took a turn.

A Jet from the Sun
10.12.2007

What powers the solar wind? Our Sun is known to emit a powerful wind of particles with gusts that can even affect astronauts and satellites orbiting Earth. The cause of the solar wind...

Sun, Moon, Hot Air Balloon
6.06.2003

Anticipating the celestial shadow play of a solar eclipse, sky gazers across Germany watched the Sun rise on May 31. In Bonn, astrophotographer Thilo Kranz had set up his small refractor telescope and camera on the Kennedy Bridge across the Rhein river to get a good view to the northeast.

APOD: 2023 June 11 Б The Sun and Its Missing Colors
11.06.2023

Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device. The spectrum was created at the McMath-Pierce Solar Observatory and shows, first off, that although our white-appearing Sun emits light of nearly every color, it appears brightest in yellow-green light.

APOD: 2026 August 6 Б New Sharpest Image of the Sun Uncovers Instability
6.08.2026

What does the new sharpest image of our Sun show? Instability. To be clear, a certain kind of interactive process called the Kelvin-Helmholtz instability (KHI). This instability can create waves and swirls when two streams flow past each other -- in this case variable streams of solar magnetic plasma.