Milky Way Voyager
2.09.2017

Launched in 1977 on a tour of the outer planets of the Solar System, Voyager 1 and 2 have become the longest operating and most distant spacecraft from Earth. Nearly 16 light-hours from...

APOD: 2024 September 11 Б A Night Sky over the Tatra Mountains
11.09.2024

A natural border between Slovakia and Poland is the Tatra Mountains. A prominent destination for astrophotographers, the Tatras are the highest mountain range in the Carpathians. In the featured image taken...

Sunset Afterimage
31.05.2025

On May 7, the Sun setting behind a church bell tower was captured in this filtered and manipulated digital skyscape from Ragusa, Sicily, planet Earth. In this version of the image the colors look bizarre.

APOD: 2025 November 17 Б Comet Lemmons Wandering Tail
17.11.2025

What has happened to Comet Lemmon's tail? The answer is blowing in the wind Б the wind from the Sun in this case. This continuous outflow of charged particles from...

Hot Stars in the Southern Milky Way
7.05.1999

Hot blue stars, red glowing hydrogen gas, and dark, obscuring dust clouds are strewn through this dramatic region of the Milky Way in the southern constellation of Ara (the Altar). About 4,000 light-years from Earth, the stars at the left are young, massive, and energetic.

Escape From The Sun
20.11.1997

Twisted magnetic fields arching from the solar surface can trap ionized gas, suspending it in huge looping structures. These majestic plasma arches are seen as prominences above the solar limb. On September 14, this...

Sunlight Through Saturns Rings
24.06.2000

Normally, earth-bound astronomers view Saturn's spectacular ring system fully illuminated by reflected sunlight. However, this intriguing picture was made to take advantage of an unusual orientation, with the Sun actually illuminating the rings from below. The three bright ring features are visible because the rings themselves are not solid.

Hot Stars in the Southern Milky Way
22.12.2001

Hot blue stars, red glowing hydrogen gas, and dark, obscuring dust clouds are strewn through this dramatic region of the Milky Way in the southern constellation of Ara (the Altar). About 4,000 light-years from Earth, the stars at the left are young, massive, and energetic.

A Green Flash from the Sun
9.09.1997

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.

A Martian Halloween
31.10.2005

From sunset to sunrise, an unusually bright yellowish orb will hang in the sky this Halloween: Mars. Yesterday, Earth passed Mars as they orbited the Sun, bringing Mars closer than it will be for the next thirteen years. Tonight though, Mars will be nearly as bright as last night, a beacon of extraterrestrial spookiness.