A Green Flash from the Sun
9.09.1997

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.

A Martian Halloween
31.10.2005

From sunset to sunrise, an unusually bright yellowish orb will hang in the sky this Halloween: Mars. Yesterday, Earth passed Mars as they orbited the Sun, bringing Mars closer than it will be for the next thirteen years. Tonight though, Mars will be nearly as bright as last night, a beacon of extraterrestrial spookiness.

APOD: 2009 April 6 The International Space Station Expands Again
6.04.2009

The developing International Space Station (ISS) has changed its appearance again. In a recently completed mission, the Space Shuttle orbiter Discovery visited the ISS and added components that included a new truss and new solar panels.

When Venus Rises with the Sun
8.06.2012

This dramatic telephoto view across the Black Sea on June 6 finds Venus rising with the Sun, the planet in silhouette against a ruddy and ragged solar disk. Of course, the reddened light...

A Cold December Night
22.12.2018

They say Orion always comes up sideways, and he does seem to on this cold December night. The bright stars of the familiar northern winter constellation lie just above the snowy tree tops surrounding a cozy cottage near the town of Ustupky in the Czech Republic.

All Sky Moon Shadow
27.04.2024

If the Sun is up but the sky is dark and the horizon is bright all around, you might be standing in the Moon's shadow during a total eclipse of the Sun. In fact, the all-sky Moon shadow shown in this composited panoramic view was captured from a farm near Shirley, Arkansas, planet Earth.

APOD: 2025 June 14 Б Meteors and Satellite Trails over the Limay River
14.06.2025

What are all those streaks in the sky? A galaxy, many satellite trails, and a few meteors. First, far in the distance, the majestic band of our Milky Way Galaxy runs down the left. Mirroring it on the right are several parallel trails of Earth-orbiting Starlink satellites. Many fainter satellite trails also crisscross the image.

Regulus Occulted
2.08.1999

On May 21, viewed from the continental US, a star winked out as it passed behind the dark limb of the first-quarter Moon. The star, Regulus, is hotter than the sun, about 69 light-years distant, and shines in Earth's skies as the brightest star in the constellation Leo, the Lion.

The First Lunar Observatory
8.06.1996

The first and only lunar astronomical observatory was deployed by the Apollo 16 crew in 1972. The Far Ultraviolet Camera / Spectrograph used a 3-inch diameter telescope to photograph the Earth, various nebulae, star clusters, and the Large Magellanic Cloud.

Name This Martian Robot
26.11.2002

NASA will launch two robots to Mars next year and you can help name them. The Mars Exploration Rovers are scheduled for launch on or near this coming June, when Mars and Earth are relatively close in their orbits.