[meteorite-list] The Planetary Society Launches Cosmic Guessing Game: The Great Comet Crater Contest

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 21 15:39:31 2005
Message-ID: <200504211939.j3LJd1706810_at_zagami.jpl.nasa.gov>

http://planetary.org/news/2005/deep_impact_contest_0421.html

The Planetary Society Launches Cosmic Guessing Game:
The Great Comet Crater Contest

by Susan Lendroth
The Planetary Society
April 21, 2005

If you slam a chunk of metal into a comet at extremely high speed, will
it sink like a stone in snow or blast a sizeable crater out of the
surface? The Planetary Society invites you to make your best guess on
how big the hole will be when NASA's Deep Impact mission releases an
impactor projectile in the path of Comet Tempel 1 for a planned
collision on July 4, 2005. The "Great Comet Crater Contest" can be found
at http://planetary.org/deepimpact .

When Deep Impact plans its impact with Comet Tempel 1, the flyby spacecraft
will watch the birth of a new crater with its cameras and other instruments.
By studying the size and shape of the hole, and the composition and
motion of the comet debris that flies away from the impact, scientists
hope to learn how comets are put together. Are comets as solid as rocks
or as fluffy as snowballs? The Deep Impact mission will attempt to find
out in a dramatic way.

"Behind the scenes, even the experts are participating in Comet Crater
Pools!" said Emily Lakdawalla, The Planetary Society's Science and
Technology Coordinator. "So The Planetary Society wants space
enthusiasts everywhere to join the fun and 'guesstimate' how big a
crater it will be, based on what scientists think they know about Tempel 1."

Scientists can only guess how big of a crater
Deep Impact will make on Tempel 1
because they are not certain what the composition or structure of the
comet is. They do know that Comet Tempel 1 is irregularly shaped and its
size is estimated to be 14.4 by 4.4 by 4.4 kilometers (8.9 by 2.7 by 2.7
miles) across. The density of the comet is estimated to be less than
that of water, meaning it is probably quite porous.

Comet Tempel 1 will hit the copper impactor--which weighs 370 kilograms
(816 pounds)--with a velocity of 10.2 kilometers per second (22,800
miles per hour). Based on experiments and theoretical models
incorporating the best guesses for Tempel 1's properties, scientists
predict that the impact crater will be "on the order of 100 meters [330
feet] across." In other words, the actual size of the crater is likely
to be closer to 100 meters than it is to be 10 meters or 1000 meters,
but that still leaves a lot of wiggle room for guessing its size.

That's where the contest comes into play. Anyone may enter the Great
Comet Crater Contest by logging on to The Planetary Society's website.
Deep Impact mission facts and figures
will help entrants come up with their best educated guess for the
diameter of the crater that Deep Impact will create on the surface of
Comet Tempel 1. Only ONE contest entry per person is allowed.

Guesses must be made in meters, but the website does include a
conversion chart for Americans who are more comfortable thinking in feet
and inches. Contest participants may enter online at the website or may
mail their entries on a postcard to the Great Comet Crater Contest, The
Planetary Society, 65 N Catalina Ave., Pasadena, CA, 91106. The postcard
must include the entrant's name, mailing address, email address, phone
number, and the guessed diameter of the crater. All entries must be
received prior to the moment that the impactor strikes Tempel 1, 05:50
GMT on 4 July 2005 (10:50 p.m. PDT on July 3).

Three grand prizes will be awarded for the best guess of the crater's
diameter. All entrants who guess within 5% of the correct crater
diameter will be entered into drawings for the grand prize. Runner-Up
prizes will be awarded to up to 150 additional correct entrants.

Each grand prize will be a custom-made plaque from Ball Aerospace, who
built the Deep Impact Spacecraft. The plaque will be made of the same
kind of copper material that makes up the heavy mass of the impactor,
laser-engraved with the mission logo. The grand prize winners will also
each receive a complimentary Planetary Society membership. The runner-up
prizes will consist of a certificate and a Deep Impact Spacecraft paper
model provided by Ball Aerospace.

"For years the Deep Impact science team has been debating about the size
of the crater that will form because that will teach us so much about
the interior of the comet," said Lucy McFadden, Deep Impact
co-investigator, University of Maryland. "We are pleased that The
Planetary Society is offering this contest so that the public can
anticipate the experiment's outcome with us."

The Deep Impact mission is led by Principal Investigator Michael A'Hearn
at the University of Maryland. Ball Aerospace & Technologies Corp., in
association with the University of Maryland and the Jet Propulsion
Laboratory (JPL), developed and built the Deep Impact Flyby spacecraft,
impactor spacecraft, and science instruments, including three
telescopes, two cameras and a spectrometer for analyzing the interior of
the comet. Deep Impact is the eighth mission in NASA's Discovery
Program, and the first mission to ever attempt impact with a comet
nucleus in an effort to probe beneath its surface.
Received on Thu 21 Apr 2005 03:39:01 PM PDT