Recurrent Nova RS Ophiuci
24.02.2006

This pretty star field in the constellation Ophiucus is centered on a star not often seen - RS Ophiuci. In fact, early last week RS Oph suddenly became visible to the naked eye for the first time since 1985.

Spacecrafts Streak Over Colorado
14.03.2011

Have you ever seen a "star" drifting slowly overhead, but not known what it was? Sometimes even pointing it out to friends or family will only lead to a shrug. What you are seeing...

Mars in the Loop
9.08.2012

This composite of images spaced some 5 to 7 days apart from late October 2011 (top right) through early July 2012 (bottom left), traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky.

The Tarantula Nebula
26.02.2016

The Tarantula Nebula is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud, about 180 thousand light-years away. The largest, most violent star...

APOD: 2023 September 6 Б HESS Telescopes Explore the High Energy Sky
6.09.2023

They may look like modern mechanical dinosaurs, but they are enormous swiveling eyes that watch the sky. The High Energy Stereoscopic System (H.E.S.S.) Observatory is composed of four 12-meter reflecting-mirror telescopes surrounding a larger telescope housing a 28-meter mirror.

Gamma Ray Moon
17.04.1999

What if you could see gamma rays (photons with more than 40 million times the energy of visible light)? If you could, the Moon would appear brighter than the Sun! This startling notion...

Unexplained Dimmings in KIC 8462852
13.06.2016

Why does star KIC 8462852 keep wavering? Nobody knows. A star somewhat similar to our Sun, KIC 8462852 was one of many distant stars being monitored by NASA's robotic Kepler satellite to see if it had planets.

Jupiters Magnetic Field from Juno
25.02.2020

How similar is Jupiter's magnetic field to Earth's? NASA's robotic Juno spacecraft has found that Jupiter's magnetic field is surprisingly complex, so that the Jovian world does not have single magnetic poles like our Earth.

Salt Water Remnants on Ceres
1.09.2020

Does Ceres have underground pockets of water? Ceres, the largest asteroid in the asteroid belt, was thought to be composed of rock and ice. At the same time, Ceres was known to have unusual bright spots on its surface. These bright spots were clearly imaged during Dawn's exciting approach in 2015.

APOD: 2024 June 30 Б Earthrise: A Video Reconstruction
30.06.2024

About 12 seconds into this video, something unusual happens. The Earth begins to rise. Never seen by humans before, the rise of the Earth over the limb of the Moon occurred about 55.5 years ago and surprised and amazed the crew of Apollo 8.