Helios Helium
16.05.1998

This image of the relatively quiet Sun was made using ultraviolet light emitted by ionized Helium atoms in the Solar chromosphere. Helium was first discovered in the Sun in 1868, its name fittingly derived from from the Greek word Helios, meaning Sun.

Equinox and the Iron Sun
23.09.2010

Today, the Sun crosses the celestial equator heading south at 03:09 Universal Time. Known as an equinox, this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. Equinox means equal night.

Comet Leonard from Space
15.12.2021

What does Comet Leonard look like from space? Today's featured image from Origin.Space's Yangwang-1 space telescope shows not only the currently bright comet -- but several other space delights as well. Taken...

Hyakutake: Comet Atmosphere
10.04.1998

The atmosphere of a comet comes and goes. Approaching the sun, it swells as material from the icy cometary nucleus is warmed and evaporated by increasing sunlight. Immense but tenuous and fleeting, the inner atmosphere or inner "coma" of comet Hyakutake is seen in this false color picture.

Bright Nebulae in M33
17.10.2009

Gorgeous spiral galaxy M33 seems to have more than its fair share of bright emission nebulae. In fact, narrow-band and broad-band image data are combined in this beautifully detailed composite to trace the reddish emission nebulae, star forming HII regions, sprawling along loose spiral arms that wind toward the galaxy's core.

NGC 7023: The Iris Nebula
3.09.2021

These cosmic clouds have blossomed 1,300 light-years away, in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers.

NGC 7023: The Iris Nebula
2.09.2023

These cosmic clouds have blossomed 1,300 light-years away in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers.

NGC 7023: The Iris Nebula
25.07.2024

These cosmic clouds have blossomed 1,300 light-years away in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers.

APOD: 2024 December 31 Б The Twisted Disk of NGC 4753
31.12.2024

What do you think this is? HereБs a clue: it's bigger than a bread box. Much bigger. The answer is that pictured NGC 4753 is a twisted disk galaxy, where unusual dark dust filaments provide clues about its history.

NGC 7023: The Iris Nebula
16.01.2026

These cosmic clouds have blossomed 1,300 light-years away in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers.