Venus and the Triply Ultraviolet Sun
5.03.2022

This was a very unusual type of solar eclipse. Typically, it is the Earth's Moon that eclipses the Sun. In 2012, though, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.

A Large Tsunami Shock Wave on the Sun
21.05.2022

Tsunamis this large don't happen on Earth. During 2006, a large solar flare from an Earth-sized sunspot produced a tsunami-type shock wave that was spectacular even for the Sun. Pictured here, the tsunami...

In the Arms of NGC 1097
15.11.2022

Spiral galaxy NGC 1097 shines in southern skies, about 45 million light-years away in the heated constellation Fornax. Its blue spiral arms are mottled with pinkish star forming regions in this colorful galaxy portrait.

Unraveling NGC 3169
1.03.2023

Spiral galaxy NGC 3169 looks to be unraveling like a ball of cosmic yarn. It lies some 70 million light-years away, south of bright star Regulus toward the faint constellation Sextans. Wound up spiral arms are pulled out into sweeping tidal tails as NGC 3169 (left) and neighboring NGC 3166 interact gravitationally.

Ares 3 Landing Site: The Martian Revisited
22.03.2024

This close-up from the Mars Reconnaissance Orbiter's HiRISE camera shows weathered craters and windblown deposits in southern Acidalia Planitia. A striking shade of blue in standard HiRISE image colors, to the human eye the area would probably look grey or a little reddish.

Unraveling NGC 3169
22.05.2024

Spiral galaxy NGC 3169 looks to be unraveling like a ball of cosmic yarn. It lies some 70 million light-years away, south of bright star Regulus toward the faint constellation Sextans. Wound up spiral arms are pulled out into sweeping tidal tails as NGC 3169 (left) and neighboring NGC 3166 interact gravitationally.

APOD: 2026 June 2 Б The Vela Supernova Remnant
1.06.2026

The explosion is over, but the consequences continue. About twelve thousand years ago, a relatively normal star in the constellation Vela suddenly exploded, creating a strange point of light briefly visible to humans living near the beginning of recorded history.

Neutron Mars
14.03.2002

Looking for water on Mars, researchers using detectors on board the orbiting Mars Odyssey spacecraft have created this false-color global map of energetic neutrons from the otherwise Red Planet. What do neutrons have to do with water?

The Deep Field
23.01.1996

The image above is part of the Hubble Deep Field and represents humanity's most distant yet optical view of the Universe. Galaxies like colorful pieces of candy fill the field, some as faint as 30th magnitude (about four billion times fainter than stars visible to the unaided eye).

The Radio Sky: Tuned to 408MHz
13.12.1997

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.