The Most Distant Sun
9.07.2007

When is the Sun most distant from Earth? It happened again just this past weekend. A common misconception is that the Sun is most distant during the winter, when it's the coldest. In truth, however, the seasonal temperatures are more greatly influenced by the number of daylight hours and how high the Sun rises.

In the Center of the Lagoon Nebula
21.05.2017

The center of the Lagoon Nebula is a whirlwind of spectacular star formation. Visible on the lower left, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. The tremendously bright nearby star, Hershel 36, lights the area.

70 Virginis b: A New Water Planet?
30.01.1996

The star 70 Virginis has a planet. This recent discovery is the second known case of a planet orbiting a normal star other than our Sun itself. The first case involved 51 Pegasi and was announced last year.

Mercury: A Cratered Inferno
12.09.2004

Mercury's surface looks similar to our Moon's. Each is heavily cratered and made of rock. Mercury's diameter is about 4800 km, while the Moon's is slightly less at about 3500 km (compared with about 12,700 km for the Earth). But Mercury is unique in many ways.

Morning Glory Clouds Over Australia
24.08.2009

What causes these long, strange clouds? No one is sure. A rare type of cloud known as a Morning Glory cloud can stretch 1,000 kilometers long and occur at altitudes up to two kilometers high.

Newton Crater: Evidence for Recent Water on Mars
26.06.2000

What could have formed these unusual channels? Inside a small crater that lies inside large Newton Crater on Mars, numerous narrow channels run from the top down to the crater floor. The above picture covers a region spanning about 3000 meters across.

Planet Near a Galaxy Core
5.05.1996

What would the night sky look like if you lived on a planet near the center of a galaxy? Now imagine that this galaxy houses a black hole billions of times more massive than a star. From this spectacular vantage point, the sky might look like the above illustration.

The Cracked Ice Plains of Europa
22.10.1996

What caused the cracks in this giant ice-ball? Jupiter's moon Europa has smoothest surface in the solar system and is composed mostly of cracked water-ice. In the above false-colored picture released last week...

BOOMERANG Images The Early Universe
3.05.2000

Drifting through the stratosphere above Antarctica in late 1998, the balloon-borne BOOMERANG telescope peered into the cosmos at millimeter wavelengths. The blotchy structures it detected are seen above in the sharpest yet picture of the universe at an early age, perhaps a mere 300,000 years old.

Dawn Before Nova
17.11.2009

Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star.