APOD: 2023 June 26 Б The Belt of Venus over Mount Everest
26.06.2023

You've surely seen it, but you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly dark and off-color.

APOD: 2024 September 18 Б The Mermaid Nebula Supernova Remnant
18.09.2024

New stars are born from the remnants of dead stars. The gaseous remnant of the gravitational collapse and subsequent death of a very massive star in our Milky Way created the G296.5+10.0 supernova remnant, of which the featured Mermaid Nebula is part.

Gangly Spiral Galaxy NGC 3184
20.09.2000

NGC 3184 is a large spiral galaxy with a small nucleus and long sprawling spiral arms. Although NGC 3184 contains hundreds of billions of stars, the blue color of its spiral arms comes mostly from relatively few bright young blue stars.

Hydrogen, Helium, and the Stars of M10
30.06.2001

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 Regolith of Asteroid Eros
3.03.2002

From fifty kilometers above asteroid Eros, the surface inside one of its largest craters appears covered with an unusual substance: regolith. The thickness and composition of the surface dust that is regolith remains a topic of much research.

Edge-On Spiral Galaxy NGC 891
28.02.1997

Is our Galaxy this thin? We believe so. The Milky Way, like NGC 891 pictured above, has the width of a typical spiral galaxy. Spirals have most of their bright stars, gas, and obscuring dust in a thin disk.

Barnacle Bill And Sojourner
8.07.1997

Deployed on a pop-up mast to its full height, the Sagan Memorial Station's IMP camera now stands about 5 feet above the surface of Ares Vallis - on Mars. This is one of the first images from its new vantage point, showing the rover Sojourner near a rock named Barnacle Bill.

The Gamma Ray Sky
21.03.1998

What if you could "see" gamma rays? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in the Universe.

Brain Crater on Mars
19.05.2004

What caused this unusual looking crater floor on Mars? Appearing at first glance to resemble the human brain, the natural phenomena that created the unusual texture on the floor of this Martian impact crater are currently under investigation. The light colored region surrounding the brain-textured region is likely sand dunes sculpted by winds.

The North Pole Of Mars
24.09.1998

The North Pole of Mars is capped by layers likely consisting of ice and dust deposited over millions of years. Imaged on September 12 - early Spring for Northern Mars - by the Mars Global Surveyor's camera, this synthesized wide-angle color view shows the rippled, eroded polar terrain covered with pinkish seasonal carbon dioxide frost.