NGC 6995: The Bat Nebula
25.11.2019

Do you see the bat? It haunts this cosmic close-up of the eastern Veil Nebula. The Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star.

Planetary Alignment over Italy
19.12.2021

It is not a coincidence that planets line up. That's because all of the planets orbit the Sun in (nearly) a single sheet called the plane of the ecliptic. When viewed from inside that plane -- as Earth dwellers are likely to do -- the planets all appear confined to a single band.

APOD: 2023 March 27 Б Aurora Over Arctic Henge
27.03.2023

Reports of powerful solar flares started a seven-hour quest north to capture modern monuments against an aurora-filled sky. The peaks of iconic Arctic Henge in Raufarhцfn in northern Iceland were already aligned with the stars: some are lined up toward the exact north from one side and toward exact south from the other.

APOD: 2025 May 12 Б Gaia Reconstructs a Side View of our Galaxy
12.05.2025

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
17.01.2003

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
12.03.1999

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.