[meteorite-list] Rosetta's Comet Target 'Releases' Plentiful Water

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 30 Jun 2014 17:10:19 -0700 (PDT)
Message-ID: <201407010010.s610AJUT021407_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?release=2014-212
  
Rosetta's Comet Target 'Releases' Plentiful Water
Jet Propulsion Laboratory
June 30, 2014

Comet 67P/Churyumov-Gerasimenko is releasing the Earthly equivalent of
two glasses of water into space every second. The observations were made
by the Microwave Instrument for Rosetta Orbiter (MIRO), aboard the
European Space Agency's Rosetta spacecraft on June 6, 2014. The
detection of water vapor has implications not only for cometary science,
but also for mission planning, as the Rosetta team prepares the
spacecraft to become the first ever to orbit a comet (planned for
August), and the first to deploy a lander to its surface (planned for
November 11).

"We always knew we would see water vapor outgassing from the comet, but
we were surprised at how early we detected it," said Sam Gulkis,
principal investigator of the MIRO instrument at NASA's Jet Propulsion
Laboratory in Pasadena, California. "At this production rate, comet
67P/Churyumov-Gerasimenko would fill an Olympic-size swimming pool in
about 100 days. But, as the comet gets closer to the sun, the gas
production rate will increase. With Rosetta, we have an amazing vantage
point to observe these changes up close and learn more about exactly why
they happen."

MIRO first detected water vapor from the comet when the Rosetta
spacecraft was about 217,000 miles (350,000 kilometers) away from it. At
the time, comet 67P/Churyumov-Gerasimenko was 363 million miles (583
million kilometers) from the sun. After the initial June 6 discovery,
water vapor was also detected every time the MIRO instrument was pointed
toward the comet. Observations are continuing to monitor variability in
the production rate, and to determine the global gas production rate, as
a function of its distance from the sun. The gas production rate that
MIRO determined provides scientists a measure of the evolution of the
comet as it moves both toward, and then away, from the sun. The gas
production rate is also important to the Rosetta navigation team
controlling the spacecraft, as this flowing gas can alter the trajectory
of spacecraft.

"Our comet is coming out of its deep-space slumber and beginning to put
on a show for Rosetta's science instruments," said Matt Taylor,
Rosetta's project scientist from the European Space Agency's Science and
Technology Centre in Noordwijk, The Netherlands. "The mission's
engineers will be using this MIRO data to help them plan for future
mission events when we are operating in close proximity to the comet's
nucleus."

Rosetta is currently about halfway between Mars and Jupiter, 261 million
miles (420 million kilometers) from Earth and 354 million miles (569
million kilometers) from the sun. Comets are time capsules containing
primitive material left over from the epoch when the sun and its planets
formed. By studying the gas, dust and structure of the nucleus and
organic materials associated with the comet, via both remote and in-situ
observations, the Rosetta mission should be a key to unlocking the
history and evolution of our solar system, as well as answering
questions regarding the origin of Earth's water and perhaps even life.
Rosetta will be the first mission in history to rendezvous with a comet,
escort it as it orbits the sun, and deploy a lander to its surface.

MIRO is a small and lightweight spectrometer instrument, the first of
its kind launched into deep space. The MIRO science team is composed of
22 scientists from the United States, France, Germany and Taiwan.
Resembling a miniaturized ground-based radio telescope, it was designed
to study the composition, velocity and temperature of gases on or near
the comet's surface and measure the temperature of the nucleus down to a
depth of several inches, or centimeters. Studying the nucleus
temperature and evolution of the coma and tail provides information on
how the comet evolves as it approaches and leaves the vicinity of the
sun, and addresses questions about why that happens. During Rosetta
flybys of the asteroids (2867) Steins and (21) Lutetia in 2008 and 2010
respectively, the instrument measured thermal emission from these
asteroids and searched for water vapor.

MIRO is one of three U.S. instruments aboard the Rosetta spacecraft. The
other two are an ultraviolet spectrometer called Alice, and the Ion and
Electron Sensor (IES). They are part of a suite of 11 science
instruments aboard the Rosetta orbiter. NASA also provided part of the
electronics package for the Double Focusing Mass Spectrometer, which is
part of the Swiss-built Rosetta Orbiter Spectrometer for Ion and Neutral
Analysis (ROSINA) instrument. NASA's Deep Space Network is supporting
ESA's Ground Station Network for spacecraft tracking and navigation.

The Microwave Instrument for Rosetta Orbiter (MIRO) was built at JPL.
Hardware subsystems for MIRO were provided by the Max-Planck Institute
for Solar System Research and the Laboratoire d'Etudes du Rayonnement et
de la Matiere en Astrophysique of the Observatoire de Paris. The
consortium also includes the Laboratoire d'Etudes Spatiales ed
d'Instrumentation en Astrophysique of the Observatoire de Paris.

Rosetta is an ESA mission with contributions from its member states and
NASA. Rosetta's Philae lander is provided by a consortium led by the
German Aerospace Center, Cologne; Max Planck Institute for Solar System
Research, Go?ttingen; French National Space Agency, Paris; and the
Italian Space Agency, Rome. JPL, a Division of the California Institute
of Technology, Pasadena, manages the U.S. contribution of the Rosetta
mission for NASA's Science Mission Directorate in Washington. JPL also
built the MIRO and hosts its principal investigator, Samuel Gulkis. The
Southwest Research Institute (San Antonio and Boulder), developed the
Rosetta orbiter's IES and Alice instruments, and hosts their principal
investigators, James Burch (IES) and Alan Stern (Alice).

For more information on the U.S. instruments aboard Rosetta, visit:

http://rosetta.jpl.nasa.gov

More information about Rosetta is available at:

http://www.esa.int/rosetta

For more information on the DSN, visit:

http://deepspace.jpl.nasa.gov/dsn

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle at jpl.nasa.gov

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Markus Bauer
European Space Agency, Noordwijk, Netherlands
011-31-71-565-6799
markus.bauer at esa.int

2014-212
Received on Mon 30 Jun 2014 08:10:19 PM PDT