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 * * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - November 5, 2004 * * *

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Welcome to S&T's Weekly News Bulletin. Images, the full text of stories
abridged here, and other enhancements are available on our Web site,
SkyandTelescope.com, at the URLs provided below. (If the links don't work,
just manually type the URLs into your Web browser.) Clear skies!

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HUBBLE SNAPS A SHADOW-SPOTTED JUPITER

Jupiter's cloud belts are always filled with spots, streaks, and swirls,
but the photo of the giant planet featured in our "Astro Image in the
News" shows five spots of another kind. Three are the black shadows of
Jupiter's moons Io, Ganymede, and Callisto. Two lighter dots are Io and
Ganymede themselves.

Triple shadow transits like this are rare....

> http://SkyandTelescope.com/news/article_1384_1.asp

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TYCHO'S SUPERNOVA COMPANION DISCOVERED

On November 11, 1572, Tycho Brahe noted the appearance of a bright new
star in the constellation Cassiopeia. This startling sight challenged the
popular Aristotelian view of an unchanging heavens and perhaps even
contributed to the opening scene of Shakespeare's Hamlet.

Today we recognize this "new star" as the most recent of only two Type Ia
supernovae recorded within our galaxy. A Type Ia supernova is thought to
occur when a white dwarf in a binary-star system steals matter from its
companion, probably a normal Sun-like star or a red giant....

An international team led by Pilar Ruiz-Lapuente (University of Barcelona,
Spain) reports in the October 28th Nature that it has found the companion
star that triggered Tycho's supernova....

> http://SkyandTelescope.com/news/article_1383_1.asp

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ASTEROIDS TELL TALE OF JUPITER MIGRATION

In 1984 astrophysicists Julio A. Fernandez and Wing-Huen Ip wrote a
seminal paper arguing that the outer planets of the solar system migrated
from where they formed to where they are today.

To understand how this could occur, consider gravity assists, such as the
Cassini spacecraft's December 30, 2000, flyby of Jupiter. Like a
table-tennis ball hitting a rotating ceiling fan and speeding up, Cassini
was flung forward an extra 2 kilometers per second by Jupiter's
gravitational field. This speeded up the spacecraft's Saturn arrival by
several months. But tiny Cassini pulled on mighty Jupiter too, decreasing
the planet's orbital momentum by a paltry 1 meter per 6 trillion years.
The planet drifted inward by an amount so tiny it would be impossible to
measure with a microscope.

That might not sound like much, but in the early days of the solar system,
the outer planets experienced trillions of close encounters with small,
icy planetesimals. While any one encounter had a negligible effect on a
planet, they added up....

Now Fred A. Franklin and a team at the Harvard-Smithsonian Center for
Astrophysics have found present-day evidence for a migrating Jupiter long
ago....

> http://SkyandTelescope.com/news/article_1382_1.asp

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HIGHLIGHTS OF THIS WEEK'S SKY

* The Moon occults Jupiter as seen from much of North America on the
morning of Tuesday the 9th.
* The crescent Moon joins Jupiter and Venus at dawn on November 9th and
10th.
* New Moon on November 12th.

For more details, see This Week's Sky at a Glance and Planet Roundup:

> http://SkyandTelescope.com/observing/ataglance/

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SOUTH PACIFIC TOTAL ECLIPSE (Advertisement)
April 3 - 19, 2005

If there's paradise on this planet, it's in the South Pacific. And if
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