APOD: 2025 May 12 Б Gaia Reconstructs a Side View of our Galaxy
11.05.2025

What does our Milky Way Galaxy look like from the side? Because we are on the inside, humanity canБt get an actual picture. Recently, however, just such a map has been made using location data for over a billion stars from ESAБs Gaia mission.

The Horsehead Nebula
19.05.1999

One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.

Galactic Supernova Remnant IC 443
21.07.1999

About 8000 years ago, a star in our Galaxy exploded. Ancient humans might have noticed the supernova as a temporary star, but modern humans can see the expanding shell of gas even today.

Stars and the Bubble Nebula
16.01.2003

Seemingly adrift in an cosmic sea of stars and gas, this delicate, floating apparition is cataloged as NGC 7635 -- The Bubble Nebula. In this wide-angle view, the Bubble nebula lies at the center of a larger complex of shocked glowing gas about 11,000 light-years distant in the fair constellation Cassiopeia.

Mars: A Journey's End
3.07.1997

Mars Pathfinder is nearing the end of its 7 month journey. The robot spacecraft is scheduled to use parachutes, rockets, and airbags to "bouncedown" on the red planet tomorrow - July 4th. This Hubble Space Telescope image of Mars was taken a few days ago to check on the weather.

Seyfert Galaxy NGC 7742
23.10.1998

This might resemble a fried egg you've had for breakfast, but it's actually much larger. In fact, ringed by blue-tinted star forming regions and faintly visible spiral arms, the yolk-yellow center of this face-on spiral galaxy, NGC 7742, is about 3,000 light-years across.

Hydrogen, Helium, and the Stars of M10
11.03.1999

Stars like the Sun use hydrogen for fuel, "burning" hydrogen into helium at their cores through nuclear fusion. But what happens when that hydrogen runs out? For a while, hydrogen burns in a shell surrounding the stellar core and the star expands to become a red giant.

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.

Iapetus in Black and White
14.09.2007

Iapetus, Saturn's third largest moon, is a candidate for the strangest moon of Saturn. Tidally locked in its orbit around the ringed gas giant, Iapetus is sometimes called the yin-yang moon because...

The Medusa Nebula
22.11.2007

Braided, serpentine filaments of glowing gas suggest this nebula's popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation.