Alpha Centauri: The Closest Star System
23.03.2003

The closest star system to the Sun is the Alpha Centauri system. Of the three stars in the system, the dimmest -- called Proxima Centauri -- is actually the nearest star. The bright stars Alpha Centauri...

GRB 990123 Host Galaxy Imaged
10.02.1999

Do the powerful explosions known as gamma-ray bursts (GRBs) originate in galaxies? This subject took on new light yesterday with the release of a Hubble Space Telescope image of the sky surrounding GRB 990123. This burst was first detected only two weeks ago and cataloged as one of the most powerful GRBs ever.

Stars in the Infrared Sky
18.09.1996

What if you could see infrared light? Because this light is less absorbed by dust than visible light, you could peer into the center of our Milky Way Galaxy. The stars there are normally hidden from direct view by the interstellar dust clouds which line the Galactic plane.

Southern Neptune
29.05.1997

Neptune, the Solar System's outermost gas giant planet, is 30 times farther from the Sun than Earth. Twelve years after a 1977 launch, Voyager 2 flew by Neptune and found surprising activity on a planet that receives only 3 percent as much sunlight as Jupiter.

SWAN Meets Galaxy
19.10.2006

This cosmic portrait recorded October 9th features the lovely blue-green coma of Comet SWAN posing with spiral galaxy NGC 5005 in the northern constellation Canes Venatici. At the time the comet (center) was in the close foreground, a mere 9 light-minutes from planet Earth, with the galaxy a more substantial 60 million light-years distant.

Mercury on the Horizon
27.01.2008

Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset.

Gigagalaxy Zoom: Galactic Center
25.09.2009

From Sagittarius to Scorpius, the central Milky Way is a truly beautiful part of planet Earth's night sky. The gorgeous region is captured here, an expansive gigapixel mosaic of 52 fields spanning 34 by 20 degrees in 1200 individual images and 200 hours of exposure time.

Pauli Exclusion Principle: Why You Don't Implode
28.02.2010

Why doesn't matter just bunch up? The same principle that keeps neutron stars and white dwarf stars from imploding also keeps people from imploding and makes normal matter mostly empty space. The observed reason is known as the Pauli Exclusion Principle.

Night of the Perseids
14.08.2010

On the night of August 12, from moonset until dawn was a good time to see meteors. Enthusiasts watched as comet dust rained on planet Earth, streaking through dark skies during the annual Perseid Meteor Shower.

The South Pole of Asteroid Vesta
19.09.2011

What created the circular structure around the south pole of asteroid Vesta? Pictured above, the bottom of the second largest object in the asteroid belt was recently imaged for the first time by the robotic Dawn satellite that arrived last month.