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Stars in our galaxy.

70% of the stars in our galaxy.
70% of the stars in our galaxy.

How Far Can You See?

Any idea how deep the eye could go if there was no atmosphere to scatter starlight? Ever wonder what optical and physical principles limit the eye's ability to see small, faint things? Have you given thought to how the "why" of astronomy changed before and after the telescope? In this article Jeff Barbour explores the limits of human sight - with and without the telescope. Learn more about the equipment available to contemporary amateurs making backyard astronomy the "extra-terrestrial" hobby of choice.

LISA Will Watch Snacking Black holes.

A new space observatory called the Laser Interferometer Space Antennae, or LISA, will help help Astronomers watch black holes as they gorge on new matter, growing larger in the process. These binges are thought to cause gravitational waves, which are ripples in spacetime. LISA consists of three spacecraft separated by 4.8 million km (3 million miles) which keep track of their relative positions very carefully. As the gravitational waves pass, the spacecraft should move relative to each other, like boats floating on the ocean when a wave goes past. LISA should launch in 2008, and will hopefully detect several black hole events a year.

Red Dwarfs Destroy Their Dusty Disks.

Red dwarfs are smaller and cooler than our own Sun, but they account for 70% of the stars in our galaxy. Astronomers have wondered why there are so many red dwarfs, but they never seem to have protoplanetary discs of dust surrounding them, indicating the formation of new planets. These stars are too small to remove dust the way larger stars do it, but Astronomers from UCLA think they could be using a process called "stellar wind drag". Even though they're smaller, red dwarfs can have very intense magnetic fields, producing a powerful solar wind. It's this solar wind that removes the dust, hiding evidence of planet formation.

Huygens Landed in Mud.

Scientists at the European Space Agency now believe that Huygens landed with a splat when it reached the surface of Titan last Friday. They reached this conclusion because the probe's downward-facing High Resolution Thermal Imager camera lens has accumulated material since Huygens landed. This means that the probe has probably been settling down into the muck. Another possiblity, though, is that it steamed hydrocarbons off the surface which are collecting on the lens.

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