Gliese 581 and the Habitable Zone
26.04.2007

The faint, unremarkable star centered in this skyview is Gliese 581, a mere 20 light-years away toward the constellation Libra. But astronomers are now reporting the discovery of a remarkable system of three planets orbiting Gliese 581, including the most earth-like planet found beyond our solar system.

Asteroid 3753: Earth's Curious Companion
18.06.1997

Earth is not alone. It orbits the Sun with a small companion: Asteroid 3753. First discovered in 1986 and designated 1986 OT, this five kilometer rock was recently found to orbit the Sun while executing a strange dance with the Earth. A portion of the asteroid's complex orbit is shown above.

A Space Station Crosses a Busy Sun
11.04.2022

Typically, the International Space Station is visible only at night. Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot several times a year from many locations.

A Martian Eclipse: Phobos Crosses the Sun
9.05.2022

What's that passing in front of the Sun? It looks like a moon, but it can't be Earth's Moon, because it isn't round. It's the Martian moon Phobos. The featured video was taken from the surface of Mars a month ago by the Perseverance rover.

Full Moon Silhouettes
10.10.2021

Have you ever watched the Moon rise? The slow rise of a nearly full moon over a clear horizon can be an impressive sight. One impressive moonrise was imaged in early 2013 over Mount Victoria Lookout in Wellington, New Zealand.

Nearby Cepheid Variable RS Pup
9.09.2013

It is one of the most important stars in the sky. This is partly because, by coincidence, it is surrounded by a dazzling reflection nebula. Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous.

A Sundial for Mars
28.04.1999

When Mars Surveyor arrives at Mars in 2002, it will carry a sundial. Even though batteries and a solar array will power the Mars Surveyor Lander, the sundial has been included to allow a prominent public display of time.

Rotating Titan in Infrared Light
15.02.2006

Titan is one of the strangest places in our Solar System. The only moon known with thick clouds, this unusual satellite of Saturn shows evidence of evaporating lakes created by methane rain. The clouds...

Stonehenge: Ancient Monument to the Sun
12.09.1999

Stonehenge consists of large carved stones assembled about 4000 years ago. Long before modern England was established, ancient inhabitants somehow moved 25 ton rocks nearly 20 miles to complete it. From similar constructs...

NGC 2440 Nucleus: The Hottest Star?
30.11.1995

In the center of the above photograph lies a star with one of the hottest surface temperatures yet confirmed. This bright white dwarf star's surface has been measured at greater than 200,000 degrees Celsius - more than 30 times hotter than that of our own Sun.