Solar Sail
Nearly 400 years ago astronomer Johannes Kepler observed comet tails blown by a solar breeze and suggested that vessels might likewise navigate through space using appropriately fashioned sails. It is now widely recognized that sunlight does ...
The Star Trails of Kilimanjaro
The night had no moon, but the stars were out. And camped at 16,000 feet on Mt. Kilimanjaro, photographer Dan Heller recorded this marvelous 3 1/2 hour long exposure. Here the landscape is lit mostly by the stars. Flashlights give the tents an ...
Comet NEAT in Southern Skies
After last month's dramatic swoop past the Sun, Comet NEAT (C/2002 V1) appeared as a naked-eye comet, emerging from the evening twilight in planet Earth's southern skies. On March 1st, New Zealand photographer Noel Munford captured this telephoto ...
Where People Live on Planet Earth
Where do people live on Planet Earth? Although people inhabit every continent, the highest population densities occur in Asia. Sparsely inhabited regions occur on virtually every continent, however, including the Sahara Desert in Africa, the ...
In the Center of the Lagoon Nebula
The center of the Lagoon Nebula is busy with the awesome spectacle of star formation. Visible in 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 ...
Will the Universe End in a Big Rip?
How will our universe end? Recent speculation now includes a pervasive growing field of mysterious repulsive energy that rips virtually everything apart. Although the universe started with a Big Bang, analysis of recent cosmological ...
In the Center of the Trapezium
Start with the constellation of Orion. Near Orion's belt is a fuzzy area known as the Great Nebula of Orion or M42. In this nebula is a bright star cluster known as the Trapezium, shown above. New stellar systems are forming there in gigantic ...
Stereo Eros
Get out your red/blue glasses and float next to asteroid 433 Eros, 170 million kilometers away! Orbiting the Sun once every 1.8 earth-years, asteroid Eros is a diminutive 40 x 14 x 14 kilometer world of undulating horizons, craters, boulders and ...
Fox Fur, the Unicorn, and a Christmas...
Glowing hydrogen gas fills this gorgeously detailed sky view centered on the variable star S Mon in the faint but fanciful constellation Monoceros, the Unicorn. A star forming region (NGC 2264), the complex jumble of cosmic gas and dust is about ...
Anticrepuscular Rays Over Horseshoe...
What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Pictured above are anticrepuscular rays. To understand them, start by ...
