APOD: 2024 September 1 Б The Moon Dressed Like Saturn
1.09.2024

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight, known as Da Vinci glow.

APOD: 2025 March 30 Б A Partial Solar Eclipse over Iceland
30.03.2025

What if the Sun and Moon rose together? That happened yesterday over some northern parts of planet Earth as a partial solar eclipse occurred shortly after sunrise. Regions that experienced the Moon blocking part of the Sun included northeastern parts of North America and northwestern parts of Europe, Asia, and Africa.

Time Lapse: A Total Solar Eclipse
10.12.2012

Have you ever experienced a total eclipse of the Sun? The above time-lapse movie depicts such an eclipse in dramatic detail as visible from Australia last month. As the video begins, a slight dimming of the Sun and the surrounding Earth is barely perceptible.

AR 9169: A Large Sunspot
25.09.2000

One of the largest sunspots in recent years is now crossing our Sun. Dominating active region AR 9169, the sunspot is the large dark complex visible below (west) and right of center in the above photograph of our Sun taken last Thursday.

A Powerful Solar Flare
29.10.2003

Yesterday, our Sun produced one of the most powerful solar flares in recorded history. Seen across the electromagnetic spectrum, the Sun briefly became over 100 times brighter in X-rays than normal. Over the next few days, as energetic particles emitted from these regions strike the Earth, satellite communications might be affected and auroras might develop.

APOD: 2025 October 6 Б The Changing Ion Tail of Comet Lemmon
6.10.2025

How does a comet tail change? It depends on the comet. The ion tail of Comet C/2025 A6 (Lemmon) has been changing markedly, as detailed in the featured image sequenced over six days between September 25 and October 4 (left to right) from Texas, USA.

A Volcanic Great Conjunction
20.12.2020

Where can I see the Great Conjunction? Near where the Sun just set. Directionally, this close passing of Jupiter and Saturn will be toward the southwest. Since the planetary pair...

Solar Eclipse from Uganda
8.11.2013

The Sun's disk was totally eclipsed for a brief 20 seconds as the Moon's dark umbral shadow raced across Pokwero in northwestern Uganda on November 3rd. So this sharp telescopic view of totality in clear skies from the central African locale was much sought after by eclipse watchers.

A Solar Prominence Unfurls
4.10.2008

On September 29, this magnificent eruptive solar prominence lifted away from the Sun's surface, unfurling into space over the course of several hours. Suspended in twisted magnetic fields, the hot plasma structure is many times the size of planet Earth and was captured in this view by the Sun-watching STEREO (Ahead) spacecraft.

A Solar Filament Erupts
17.09.2012

What's happened to our Sun? Nothing very unusual -- it just threw a filament. At the end of last month, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).