Star Trails of the North and South
12.02.2020

What divides the north from the south? It all has to do with the spin of the Earth. On Earth's surface, the equator is the dividing line, but on Earth's sky, the dividing line is the Celestial Equator -- the equator's projection onto the sky.

Love and War by Moonlight
16.07.2021

Venus, named for the Roman goddess of love, and Mars, the war god's namesake, come together by moonlight in this serene skyview, recorded on July 11 from Lualaba province, Democratic Republic of Congo, planet Earth.

Filaprom on the Western Limb
24.06.2022

A solar filament is an enormous stream of incandescent plasma suspended above the active surface of the Sun by looping magnetic fields. Seen against the solar disk it looks dark only because it's a little cooler, and so slightly dimmer, than the solar photosphere.

APOD: 2023 July 17 Б Shells and Arcs around Star CW Leonis
17.07.2023

What's happening around this star? No one is sure. CW Leonis is the closest carbon star, a star that appears orange because of atmospheric carbon dispersed from interior nuclear fusion. But CW Leonis also appears engulfed in a gaseous carbon-rich nebula.

Why Stars Twinkle
25.07.2000

This is what a star really looks like from the surface of the Earth. To the best the human eye can see, stars are so far away they appear the same as would infinitesimal points of light.

Mjølnir: Impact Crater
10.06.1999

The stark surface of Earth's moon is pocked with large craters, records of a history of fierce bombardment by the solar system's formative debris. It may be difficult to imagine, but nearby planet Earth itself has endured a similar cosmic pounding, though oceans, weathering, and geological

The Solar Spectrum
23.04.2006

It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

New Horizons at Io
4.04.2007

Spewed from a volcano, a complex plume rises over 300 kilometers above the horizon of Jupiter's moon Io in this image from cameras onboard the New Horizons spacecraft. The volcano, Tvashtar, is marked by the bright glow (about 1 o'clock) at the moon's edge, beyond the terminator or night/day shadow line.

Could Hydrogen Peroxide Life Survive on Mars
28.08.2007

Is there life on Mars? Although no unambiguous evidence for indigenous life on Mars has ever been found, a more speculative question -- could some life forms survive on Mars -- has taken on a new twist.

Phobos: Doomed Moon of Mars
14.04.2008

This moon is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These...