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Space-based missile defenses systems could produce dangerous space debris that would make low-Earth orbits permanently unusable, according to Joel Primack of the University of California at Santa Cruz. The orbiting anti-missile battle stations proposed by the U.S. could result in so much space junk that other satellites wouldn?t have room to operate.

Most critics of the U.S. military’s missile defense program focus on the imperfect trial results of their ground-based interceptors, which have destroyed dummy warheads in four out of six trials. But in tests, neither the target or the interceptor reach orbital velocity, so most of the debris they produce falls to the ground.
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When Earth is next hit by an asteroid, the impact may well be doubled, since a new study estimates that 16 percent of asteroids in the region of space shared by Earth’s orbit are actually double asteroids, called binaries. Evidence shows that impacts on Earth sometimes involve a pair of craters. Researchers say these pairs may have been created by the effect of Earth’s gravity, which tears asteroids apart when they come too close.

Astronomers say binary asteroids larger than 219 yards appear to be formed extremely close to Earth. Five such systems have been spotted by radar telescopes. Asteroids this close to the planet are called Near Earth Asteroids, or NEAs, and are watched closely by astronomers who fear they may one day hit Earth.
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As parts of Antarctica are fall into the sea, new satellite data shows that these dramatic changes are affecting the growth of small organisms important to the local food chain. Icebergs that have broken off from the Ross Ice Shelf have caused a 40 percent reduction in the size of the 2000-2001 plankton bloom in one of Antarctica’s most biologically productive areas. The icebergs decrease the amount of open water, which the plants need in order to reproduce.
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Children may soon be able to take a simple breath test to see if they have dyslexia. The breath test, developed by Dr. Alexandra Richardson of the University of Oxford, works by measuring biochemical imbalances in the body that are thought to underlie some behavioral and learning difficulties.
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