Sky & Telescope's News Bulletin - Aug 29

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* * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - August 29, 2003 * * *

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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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ERASING THE ANCIENT MARTIAN LANDSCAPE

When Mars was a youngster, it was a far different place. The now dry and frigid
world was arguably warmer and had flowing water on its surface. It was also a
pock-marked teenager, with active volcanoes and deep impact scars. But today
there is little evidence of the red planet's youth. And if a team of
astronomers are correct, it is because Mars has literally buried its past.

As a child, Mars formed an intricate drainage system to channel its water.
During this period, which ended roughly 3 billion years ago, impacts were
relentless as space debris bombarded the planet. The oldest geological
formations on Mars hark back to this violent period. But time has managed to
erase most of the wounds. Craters smaller than about 30 kilometers aren't found
in the numbers expected, and astronomers believe that most of these ancient
impact sites have long since eroded away.

Explaining these missing craters is difficult because the sparse and
disconnected small drainage systems visible on Mars today couldn't have carried
enough water to cause all the erosion....

http://SkyandTelescope.com/news/article_1034_1.asp

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STARFEST 2003: DARK SKIES AND ALIENS
A diary of Canada's largest annual star party

If you've never been in to a star party, I strongly recommend that you attend
one. Even if it's cloudy, you are virtually guaranteed to come away with your
astronomical batteries tremendously recharged. You meet old friends, make new
ones, and make your observing experience so much richer....

http://SkyandTelescope.com/news/article_1032_1.asp

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HUBBLE'S CLOSEST LOOK AT MARS

This past week seemingly all skygazers turned toward Mars -- the Hubble Space
Telescope included. On August 26th, controllers aimed Hubble at the red planet
and captured a series of images using the Wide Field and Planetary Camera 2
between 6:20 and 7:12 p.m. Eastern Daylight Time, only 11 hours -- and 2,422
miles -- shy of Mars's closest approach to Earth in more than 60,000 years. The
color-composite photo was assembled from frames taken with red, green, and blue
filters. The images were quickly processed and released Wednesday morning....

http://SkyandTelescope.com/news/article_1033_1.asp

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ASTRO NEWS BRIEFS

Space Infrared Telescope Facility Finally Takes Flight

After a four-month delay, the last of NASA's four "Great Observatories" lifted
off from Cape Canaveral, Florida, early Monday morning. SIRTF, the Space
Infrared Telescope Facility, will complement the Hubble Space Telescope and
Chandra X-ray Observatory, providing longer-wavelength views of the cosmos. The
infrared universe is especially rich for study, both because infrared light
penetrates interstellar dust and because much of the light from the early
universe has been redshifted deep into infrared wavelengths. The new telescope,
set to be operational in about three months, will see back to the earliest
galaxies and into dust cocoons where stars are forming.

The Delta II Heavy rocket intended to loft SIRTF last April was used instead
used for Opportunity, the second of NASA's Mars Exploration Rovers, on July
7th. But within two weeks SIRTF's replacement rocket was set up on the pad.
This launch was a little unusual in that the Delta's second stage will
accompany the observatory into solar orbit instead of being left behind. Once
clear of Earth the engine will fire to place SIRTF in an Earth-trailing solar
orbit that drifts 15 million kilometers farther from home every year....

MOST Sees First Light

A month after its June 30th launch, Canada's first space telescope, MOST
(Microvariability and Oscillations of Stars), saw first light. According to
scientists on the mission, the telescope successfully imaged its first star and
beamed the signal back to Earth. Once online full time, MOST will probe the
interiors of stars by tracking their tiny surface vibrations and will also look
for transits by small extrasolar planets. It also holds the honor of being the
smallest space telescope in orbit.

http://SkyandTelescope.com/news/article_1031_1.asp

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HIGHLIGHTS OF THIS WEEK'S SKY

* Mars is at perihelion, its closest point to the Sun in its orbit, on August
30th.
* First-quarter Moon on September 3rd.
* Mars (magnitude -2.9, in Aquarius) rises in the east-southeast in early
evening, shining brilliant, fiery yellow-orange.

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

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

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VENUS IN TRANSIT (Advertisement)

10-DAY CRUISE-TOUR FROM VENICE, ITALY, THROUGH THE GREEK ISLES - June 4-13,
2004

Rich with orange and olive groves, Corfu is a favorite international vacation
spot. Our group will disembark the ship before dawn and view the entire event
from our specially selected site in this picturesque locale.

http://www.tq-international.com/Veni...CruiseHome.htm

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Copyright 2003 Sky Publishing Corp. S&T's Weekly News Bulletin is provided as a
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*-----------------------------------------------------*
| Stuart Goldman |
* Associate Editor *
| Sky & Telescope |
* 49 Bay State Rd. Sky & Telescope: The Essential *
| Cambridge, MA 02138 Magazine of Astronomy |
*-----------------------------------------------------*

Stuart Goldman:
* * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - August 29, 2003 * * *
When Mars was a youngster, it was a far different place. The now dry and
frigid world was arguably warmer and had flowing water on its surface...

That's a possibility. Another possibility was reported in _Science_ on
22 August, 2003:

"...new data from instruments orbiting Mars builds a case for a
volcanic planet only gently touched by the chemical alteration that
water has wreaked on Earth for billions of years."

"...a team led by planetary geologist and spectroscopist Philip
Christensen of Arizona State University in Tempe finds much less of the
mineral carbonate than would be expected on a wet planet."

"...Christensen and colleagues analyzed data from the Thermal Emission
Spectrometer on the orbiting Mars Global Surveyor spacecraft to
estimate the fraction of carbonate. The wiggles and squiggles of the
spectrum are 'consistent with a small amount of carbonate,' Christensen
says, about 2% to 3%. That's no more than might form over the eons by
the dust's reaction with today's vanishingly low martian humidity, he
notes, or the higher humidities possible during the ebb and flow of
martian ice ages."

"...The work adds to growing evidence pointing to a colder, drier Mars
( Science , 22 August, p. 1037 ). And other products of extensive
weathering expected under a warm, wet climate, such as clays, are
showing up in unexpectedly tiny quantities, if at all..."

*****

My view: evidence is still too tenuous to say with certainty what kind
of past Mars had. Open minds may eventuall learn the truth.

Davoud

--
usenet *at* davidillig dawt com

Davoud wrote:

My view: evidence is still too tenuous to say with certainty what kind
of past Mars had. Open minds may eventuall learn the truth.

Hard to really develop strong evidence to support any hypothesis without
going there. Even on Earth there are such questions which are
controversial.

Phil

Davoud wrote:

My view: evidence is still too tenuous to say with certainty what kind
of past Mars had. Open minds may eventuall learn the truth.

Hard to really develop strong evidence to support any hypothesis without
going there. Even on Earth there are such questions which are
controversial.

Phil

Stuart Goldman:
* * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - August 29, 2003 * * *
When Mars was a youngster, it was a far different place. The now dry and
frigid world was arguably warmer and had flowing water on its surface...

That's a possibility. Another possibility was reported in _Science_ on
22 August, 2003:

"...new data from instruments orbiting Mars builds a case for a
volcanic planet only gently touched by the chemical alteration that
water has wreaked on Earth for billions of years."

"...a team led by planetary geologist and spectroscopist Philip
Christensen of Arizona State University in Tempe finds much less of the
mineral carbonate than would be expected on a wet planet."

"...Christensen and colleagues analyzed data from the Thermal Emission
Spectrometer on the orbiting Mars Global Surveyor spacecraft to
estimate the fraction of carbonate. The wiggles and squiggles of the
spectrum are 'consistent with a small amount of carbonate,' Christensen
says, about 2% to 3%. That's no more than might form over the eons by
the dust's reaction with today's vanishingly low martian humidity, he
notes, or the higher humidities possible during the ebb and flow of
martian ice ages."

"...The work adds to growing evidence pointing to a colder, drier Mars
( Science , 22 August, p. 1037 ). And other products of extensive
weathering expected under a warm, wet climate, such as clays, are
showing up in unexpectedly tiny quantities, if at all..."

*****

My view: evidence is still too tenuous to say with certainty what kind
of past Mars had. Open minds may eventuall learn the truth.

Davoud

--
usenet *at* davidillig dawt com