Because this seems to be a slow day, I thought I would share this notice I
received from NASA earlier today. The number of known extrasolar planets is
now reported to be just shy of 80, no small number. Even more interesting,
the newest solar systems that are being discovered are more like our own than
the first to be discovered were, which were wierd, oddly constructed systems.

Earth-like planets are still beyond our detectability limits. What we're
finding are still the gas giants, things the size of Jupiter and above, but
eventually we will be able to detect and find new Earths.

Stan, Gavin and I attended a 3-day conference earlier this year at NASA Ames
Research Center, which is just a few miles up the road from Allegro's
location. By chance, on one of the days during lunch, I sat down next to
Neville Woolf and we talked about the search for extrasolar planets for a
couple of hours, which certainly made for an enjoyable lunch.

Woolf has been tasked by Dan Goldin, the head of NASA, to find
terrestrial-like planets. While it seems evident from our conversation that
he considers the task next to impossible, it doesn't mean that he isn't
giving it the old college try. The primary mechanism by which he and others
are attempting to do this is find non-equilibrial atmospheres. Oxygen -- in
the absence of life -- should never exist as a free gas in a planet's
atmosphere, thus what they're trying to build are massively large,
space-borne optical interferometers to see if they can observe and chemically
characterize miniscule-sized planets' atmospheres in the midst of the
enormous glare of the star they orbit.

You can get a bit of an idea of what Woolf & others are up to from these web
pages:

     http://astrobiology.arc.nasa.gov/palebluedot/abstracts/woolfe.html
     http://wildcat.arizona.edu/papers/92/16/11_1_m.html

While it's going to be a long time before we actually travel to the nearest
stars (perhaps never), it may not be all that long (ten to thirty years)
before we might actually be able to measure which nearby stars offer at least
the chance for life.

Wirt Atmar


======================================

Don Savage
Headquarters, Washington                     Oct. 15, 2001
(Phone: 202/358-1547)

Amber Jones
National Science Foundation, Arlington, Va.
(Phone: 703/292-8070)

RELEASE: 01-197

MORE PLANETS EMERGE WITH SOLAR SYSTEM-LIKE ORBITS

     An international team of astronomers has discovered
eight new extrasolar planets, bringing to nearly 80 the
number of planets found orbiting nearby stars.

The latest discoveries, supported by NASA and the National
Science Foundation (NSF), uncovered more evidence of what the
astronomers are calling a new class of planets. These planets
have circular orbits similar to the orbits of planets in our
solar system.

At least two of the recently detected planets have
approximately circular orbits. This characteristic is shared
by two planets (one of them the size of Jupiter) previously
detected by the same team around 47 Ursae Majoris, a star in
the Big Dipper constellation, and one around the star Epsilon
Reticulum. The majority of the extrasolar planets found to
date are in an elongated, or "eccentric," orbit.

The further a planet lies from its star, the longer it takes
to complete an orbit and the longer astronomers have to
observe to detect it.

"As our search continues, we're finding planets in larger and
larger orbits," said Steve Vogt of the Lick Observatory,
University of California at Santa Cruz. "Most of the
planetary systems we've found have looked like very distant
relatives of the solar system -- no family likeness at all.
Now we're starting to see something like second cousins.

"In a few years' time we could be finding brothers and
sisters," he added.

"This result is very exciting," said Anne Kinney, director of
NASA's Astronomy and Physics Division at Headquarters in
Washington. "To understand the formation and evolution of
planets and planetary systems we need a large sample of
planets to study. This result, added to others in the recent
past, marks the beginning of an avalanche of data which will
help to provide the answers."

The recently detected planets range in mass from 0.8 to 10
times the mass of Jupiter, the largest planet in our solar
system. They orbit their stars at distances ranging from
about 0.07 AU (astronomical unit, or the distance from the
Sun to Earth), to three AU.

The astronomers -- from the United States, Australia, Belgium
and the United Kingdom -- are searching the nearest 1,200
stars for planets similar to those in our solar system,
particularly Jupiter-like gas giants. Their findings will
help astronomers assess the solar system's place in the
galaxy and whether planetary systems like our own are common
or rare.

For most of their discoveries, the astronomers have used the
Keck 10-meter telescope on Mauna Kea, Hawaii; the Lick three-
meter in Santa Cruz, Calif.; and the 3.9-meter Anglo-
Australian Telescope in New South Wales, Australia. To find
evidence of planets, the astronomers use a high-precision
technique developed by Paul Butler and Geoff Marcy of the
University of California at Berkeley to measure how much a
star "wobbles" in space as it is affected by a planet's
gravity.

The team also receives support from the UK and Australian
governments.

========================================

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *