Gamma Ray Moon
27.05.2006

If you could see gamma rays - photons with a million or more times the energy of visible light - the Moon would appear brighter than the Sun! The startling notion is demonstrated by this image...

Tunguska: The Largest Recent Impact Event
14.11.2007

Yes, but can your meteor do this? The most powerful natural explosion in recent Earth history occurred on 1908 June 30 when a meteor exploded above the Tunguska River in Siberia, Russia. Detonating with...

Probably a Planet for Beta Pic
28.11.2008

A mere 50 light-years away, young star Beta Pictoris became one of the most important stars in the sky in the early 1980s. Satellite and ground-based telescopic observations revealed the presence of a surrounding...

Cherenkov Telescope at Sunset
18.10.2018

On October 10, a new telescope reflected the light of the setting Sun. With dark horizon above and sunset colors below, its segmented mirror inverts an image of the beautiful evening sky in this snapshot from the Roque del Los Muchachos Observatory on the Canary Island of La Palma.

Radio, The Big Ear, and the WOW Signal
2.05.2020

Since the early days of radio and television we have been freely broadcasting signals into space. For some time now, we have been listening too. A large radio telescope at Ohio State University known as affectionately The Big Ear was one of the first listeners.

Supernova Cannon Expels Pulsar J0002
2.10.2022

What could shoot out a neutron star like a cannon ball? A supernova. About 10,000 years ago, the supernova that created the nebular remnant CTB 1 not only destroyed a massive star but blasted its newly formed neutron star core -- a pulsar -- out into the Milky Way Galaxy.

APOD: 2024 February 12 Б HFG1 & Abell 6: Planetary Nebulae
12.02.2024

Planetary nebulae like Heckathorn-Fesen-Gull 1 (HFG1) and Abell 6 in the constellation Cassiopeia are remnants from the last phase of a medium sized star like our Sun. In spite of their shapes, planetary nebulae have nothing in common with actual planets.

Phi Persei: Double Star
12.12.1997

It's clear who is the biggest star in this binary system. Based on recent results, this artist's vision of the double star Phi Persei, 720 light years away, shows a bright, rapidly rotating massive star surrounded by a disk of gas. A small companion star orbits 100 million miles away.

Comet Hale Bopp Over Indian Cove
20.04.2004

Comet Hale-Bopp, the Great Comet of 1997, was quite a sight. No comets of comparable brightness have graced the skies of Earth since then. During this next month, however, even besides the fleeting Comet Bradfield, two comets have a slight chance of rivaling Hale-Bopp and a good chance of putting on a memorable sky show.

Huygens Discovers Luna Saturni
25.03.2005

In 1655, three hundred fifty years ago on this date, Dutch astronomer Christiaan Huygens discovered Luna Saturni - now known as Saturn's moon Titan. To celebrate, consider this intriguing picture of his telescope lens, all that remains of the instrument he used, designed and constructed in collaboration with his brother, Constantijn Huygens.