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(meteorobs) Excerpt: "S&T's News Bulletin for April 2, 1999"
------- Forwarded Message
Date: Fri, 2 Apr 1999 17:52:46 -0600 (CST)
From: stargate@gtedot net
To: dedalus@latrade.com
Subject: S&T's News Bulletin for April 2, 1999
Content-Type: multipart/mixed; boundary="bbb"
SKY & TELESCOPE'S NEWS BULLETIN
APRIL 2, 1999
[...]
THE MEASURE OF EROS
Had things gone according to plan, NASA's Near Earth Asteroid Rendezvous
spacecraft would now be snugly in orbit around minor planet 433 Eros. But
last December 20th a botched rocket firing caused the spacecraft to sail
past its target. The unintended flyby wasn't devoid of scientific results,
however. According to investigator Joseph Veverka, NEAR acquired images of
Eros good enough to resolve features roughly 400 meters across. Overall,
the asteroid measures a very elongated 33 by 13 by 13 kilometers. Veverka
adds that the flyby was close enough (3,827 km) and slow enough (965 meters
per second) to alter NEAR's trajectory very slightly. These deviations were
barely measurable by tracking stations, but they allowed orbital specialist
Donald Yeomans to determine that Eros has a mass of about 7 trillion tons
and a bulk density near 2.5 grams per cubic centimeter. This density is
similar to that of asteroid 243 Ida and much higher than that of 253
Mathilde, whose interior is apparently very porous. A careful search by
NEAR turned up no satellites circling Eros any larger than 50 meters
across. NEAR will close in for another attempt to orbit Eros on February
14, 2000.
MARS OBSERVING ALERT
Dan Troiani and Walter Haas of the Association of Lunar and Planetary
Observers (ALPO) have issued an urgent notice to Mars observers about the
sudden appearance of clouds in the region of Ascraeus Lacus and Nix
Olympica (the albedo feature associated with volcano Olympus Mons). Troiani
e-mails this note: "The clouds were imaged by David Moore (Arizona) on
March 29th, and also by Don Parker (Florida) on March 29th at 7:00
Universal Time. The cloud formation appears to be over Olympus Mons.
Confirmation photographs were taken by Frank J. Melillo with a Wratten 47
(violet) filter on March 29th. Both Dan Joyce and Dan Troiani (Illinois)
made sketches of the event."
For details about this alert visit SKY & TELESCOPE's Web site
(http://www.skypub.com/); for more about observing Mars during its
favorable apparition this spring, see the April 1999 issue, page 106.
[...]
More details, sky maps, and news of other celestial events appear each
month in SKY & TELESCOPE, the essential magazine of astronomy. See our
enormous Web site at www.skypub.com. Clear skies!
SKY & TELESCOPE, P.O. Box 9111, Belmont, MA 02478 * 617-864-7360 (voice)
=======================================================================
Copyright 1999 Sky Publishing Corporation. S&T's Weekly News Bulletin and
Sky at a Glance stargazing calendar are provided as a service to the
astronomical community by the editors of SKY & TELESCOPE magazine.
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=======================================================================
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