God Bless America

May 10 2000

* Recent News Briefs from NASA: 
Picturesque Coronal Mass Ejections 
Computers Traveling at the Speed of Light

* News Stories from Space and Flight (edited for length)
U.S. Improves Quality of GPS Signals 
Hubble Discovers "Missing" Hydrogen in Universe
Astronomers Puzzled By "Dog Bone" Asteroid

 Picturesque Coronal Mass Ejections

The wide field coronagraph on board the orbiting Solar and Heliospheric Observatory recorded a series of dazzling coronal mass ejections (CMEs) on May 5, 2000, with Mercury, Jupiter and Saturn in the background. These eruptions apparently came from active sunspot groups that are just over the Sun's western limb. CMEs like these, seen in profile, are unusually beautiful.

This weekend the visible disk of the Sun is remarkably devoid of large sunspots as we approach the peak of the sunspot cycle in mid-2000.

For more information and images please visit: http://www.spaceweather.com 

 Computers Traveling at the Speed of Light

The speed of computers has now become a pressing problem as electronic circuits reach their miniaturization limit and the rapid growth of the Internet demands faster speeds and larger bandwidths than electronic circuits can provide. Computers used to work in milliseconds (1,000ths), then moved up to microseconds (millionths), now are approaching nanoseconds (billionths) for logic operations, and picoseconds (trillionths!) for the switches and gates in chips. But the very materials in which electronic signals travel bog down the process. NASA scientists at Marshall Space Flight Center have turned to light itself as a medium. Light travels at 186,000 miles per second, or 982,080,000 feet per second -- just right for doing things very quickly in microminiaturized computer chips. Follow the link at http://www.nasa.gov/today  to learn about optical computers.

U.S. Improves Quality of GPS Signals

The United States has ended a long-standing practice of intentionally degrading the quality of signals from its constellation of Global Positioning System (GPS) satellites, paving the way for more accurate civilian uses of the system.

Effective midnight Greenwich Mean Time Monday, May 1, the U.S. military stopped using a feature known as Selective Availability (SA) that intentionally reduced the accuracy of GPS signals available to non-military users.

"In plain English, we are unscrambling the signal," said presidential science advisor Neal Lane during a Monday press conference that announced the change.

"The decision to discontinue SA is the latest measure in an on-going effort to make GPS more responsive to civil and commercial users worldwide," U.S. President Bill Clinton said in a statement.

Hubble Discovers "Missing" Hydrogen in Universe

Using an innovative detection technique, astronomers announced Wednesday that they have detected the "missing" hydrogen that makes up half of the ordinary mass of the universe.

The astronomers, from Princeton University and the University of Wisconsin, indirectly located the otherwise-invisible hydrogen by detecting a tracer, ionized oxygen, in clouds of gas in intergalactic space.

"This is a successful, fundamental test of cosmological models," said Princeton's Todd Tripp. "This provides strong evidence that the models are on the right track."

Astronomers had long predicted that such clouds of gas had formed in the aftermath of the Big Bang, creating vast, intricate structures of gas. Clusters of galaxies had been predicted to form where those filaments intersected, heating up the gas. However, until now that gas had eluded detection even though it was believed to comprise up to half the mass of normal matter un the universe.

Astronomers Puzzled By "Dog Bone" Asteroid

(Note: Photo available from NASA site at http://www.nasa.gov/today/index.html )

Astronomers released Thursday radar images of a large main belt asteroid that, for reasons as yet unknown, vaguely resembles a metallic dog bone the size of New Jersey.

The images of the asteroid 216 Kleopatra, published in the May 5 issue of the journal Science, show that the asteroid, 217 km (135 mi.) long and 94 km (58 mi.) wide, consists of two distinct lobes connected by a long, cylindrical region.

While dual-lobed asteroids have been observed in the past, in previous cases the two sections were closely connected, and not as far apart from each other as seen here. "With its dog bone shape, Kleopatra is one of the most unusual asteroids we've seen in the solar system," said JPL's Steven Ostro, leader of a team of astronomers who performed the observations.

"What is clear," said Michael Nolan of Arecibo Observatory, "is that this object's collision history is extremely unusual."

"It is amazing that nature has produced a giant metallic object with such a peculiar shape," said Ostro. "We can think of some possible scenarios, but at this point none is very satisfying."

"The object's existence," he concluded, "is a perplexing mystery that tells us how far we have to go to understand more about asteroid shapes and collisions."

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Submitted by
CMDR Constance Sanders
USS Yorktown
Chief, Space Activities Committee, SFC
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