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- Path: sparky!uunet!dtix!darwin.sura.net!convex!news.utdallas.edu!bcollins
- From: bcollins@utdallas.edu (Arlin B. Collins)
- Newsgroups: sci.astro
- Subject: S&T Weekly News Bulletin
- Message-ID: <1992Aug17.030333.17761@utdallas.edu>
- Date: 17 Aug 92 03:03:33 GMT
- Sender: usenet@utdallas.edu
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- Organization: Univ. of Texas at Dallas
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-
- ****
- SKY & TELESCOPE NEWS BULLETIN -- AUGUST 14, 1992
-
- YUCATAN NEWS
- Today's issue of SCIENCE magazine carries a report that is big news for
- those in the impact biz. Using sensitive dating techniques, a team of
- scientists have finally determined an accurate date for a large impact
- feature buried beneath the Yucatan peninsula in Mexico. That date is
- 64.98 million years, with an error of no more than 50,000 years. The
- result virtually certifies that the 100-mile-wide crater is indeed the
- cause of a tremendous extinction of life on Earth 65 million years ago.
- Moreover, the age of the rock sample tested is indistinguishable from
- that of a thick bed of impact ejecta "splashed" onto nearby Haiti.
-
- PERSEIDS: A FIRST REPORT
- A remarkably consistent picture of the 1992 Perseid meteor shower has
- emerged from early reports submitted by SKY & TELESCOPE's readers.
- Although a nearly full Moon compromised everyone's observations, the
- consensus seems to be that this year's shower was better than average.
- But it was not the meteor storm that some had hoped might occur as a
- precursor to the possible return of Comet Swift-Tuttle -- the source of
- the Perseids. Last year, for example, Japanese observers watched in
- amazement as Perseids flashed by at the rate of 300 per hour.
-
- German amateur Mark Hardaker reports seeing more than two dozen
- Perseids brighter than 2nd magnitude in an hour at local midnight on
- August 12th, and more than 20 of them in the hour thereafter. John
- Bortle saw a similar number of Perseids soon afterward from his home in
- New York. According to Joseph Lynch, who described how to monitor
- meteors with radio equipment in the August issue of SKY & TELESCOPE,
- ham operators recorded the peak radio activity around 18 hours
- Universal time on August 11th, which was during daylight hours in North
- America.
-
- NAKED-EYE SUNSPOT
- Right now the sunspot count is moderate, with Caspar Hossfield
- reporting an index of 81 for the week ending August 12th. But numbers
- can be deceiving. Rick Krezewski called in to alert us of a huge
- naked-eye sunspot on the east side of the disk. Rick says the group has
- an unusually large and detailed penumbra, or skirt, around the darker
- interior region. If you do go looking for this sunspot, please observe
- safely and take the proper precautions. Use filters specially made for
- solar viewing, or a welder's glass of shade number 13 or 14.
-
- -----THIS WEEK'S "SKY AT A GLANCE"
-
- AUG 17 -- MON
- Venus and Jupiter are just 5 degrees apart and closing! See Planet
- Roundup.
-
- AUG 18 -- TUE
- Saturn's brightest moon Titan can be seen in a small telescope four
- ring lengths west of the planet for the next couple nights.
-
- AUG 19 -- WED
- Venus and Jupiter are 3 degrees apart.
-
- AUG 20 -- THU
- Mercury is at greatest elongation, 18 degrees west of the Sun in the
- dawn.
-
- AUG 21 -- FRI
- Last quarter Moon (exact at 6:01 a.m. Eastern daylight time). Before
- dawn look for the Pleiades close to the Moon. Binoculars help. Tomorrow
- before dawn, the Moon will be near Mars and Aldebaran.
-
- AUG 22 -- SAT
- Venus and Jupiter in conjunction, only 1/3 degree or less apart! Scan
- for them with binoculars just above the horizon due west 30 minutes
- after sunset. Venus is the brighter one.
-
- AUG 23 -- SUN
- Venus and Jupiter are still within 1 degree apart.
-
- ----- THIS WEEK'S PLANET ROUNDUP
-
- MERCURY is very low in the east-northeast during dawn. Don't confuse it
- with Procyon to its right; Mercury is the one under Castor and Pollux.
-
- VENUS is barely above the western horizon in bright twilight shortly
- after sunset, close to fainter Jupiter. The two planets pass very near
- each other on the 22nd. Use binoculars!
-
- MARS, in Taurus, rises around 12:30 a.m. and shines high in the east
- before dawn. It's a few degrees from similarly-colored Aldebaran, which
- is a bit fainter.
-
- JUPITER is near Venus after sunset; see above.
-
- SATURN shines in the southeast after darkness falls. It's higher in the
- south by midnight.
-
- URANUS and NEPTUNE, 6th and 8th magnitude, respectively, are in the
- south after dark.
-
- PLUTO is a 14th-magnitude speck getting low in the southwest after
- dusk.
-
- -----
- SkyLine is provided by the publishers of "Sky & Telescope" magazine.
- It may not be used for profit. It is released via "go astroforum" on
- CompuServe, Friday afternoons.
- --
- Arlin B Collins CompuServe: INTERNET:bcollins@utdallas.edu :-)
-