[meteorite-list] Rosetta's MIRO Instrument Maps Comet Water

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 19 Jun 2015 19:17:49 -0700 (PDT)
Message-ID: <201506200217.t5K2Hni2029892_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4632

Rosetta's MIRO Instrument Maps Comet Water
Jet Propulsion Laboratory
June 19, 2015

Since last September, scientists using NASA's Microwave Instrument for
Rosetta Orbiter (MIRO) on the European Space Agency's Rosetta spacecraft
have generated maps of the distribution of water in the coma of comet
67P/Churyumov-Gerasimenko, as the comet's orbit brings it closer to the
sun.

MIRO is able to detect water in the coma by measuring the direct emission
from water vapor in the coma and by observing absorption of radiation
from the nucleus at water-specific frequencies as the radiation passed
through the coma.

On Sept. 7, 2014, when Rosetta was 36 miles (58 kilometers) from the center
of the comet, the MIRO team obtained their first map of the nucleus of
67P/C-G and its surroundings. They discovered the highest density of water
just above the comet's neck, close to the north pole of the comet's rotation
axis. In this narrow region, the number of water molecules is up to two
orders of magnitude higher than elsewhere in the coma. Lower but still
substantial amounts of water were detected over on the day side of the
nucleus up to the terminator between the illuminated and dark side. The
lowest amounts of water are found on the comet's night side -- particularly
over its southern polar regions. This could be due to either local outgassing
or circulation effects within the coma, causing water to flow from the
day to the night side.

A European Space Agency blog post on the MIRO data is online at:

http://blogs.esa.int/rosetta/2015/06/19/miro-maps-water-in-comets-coma/

For a deeper dive into the science the blog post is based on, please visit:

http://www.aanda.org/component/article/?access=doi&doi=10.1051/0004-6361/201526094

The MIRO instrument is a small and lightweight spectrometer that can map
the abundance, temperature and velocity of cometary water vapor and other
molecules that the nucleus releases. It can also measure the temperature
up to about one inch (two centimeters) below the surface of the comet's
nucleus. One reason the subsurface temperature is important is that the
observed gases likely come from sublimating ices beneath the surface.
By combining information on both the gas and the subsurface, MIRO is able
to study this process in detail.

Comets are time capsules containing primitive material left over from
the epoch when the sun and its planets formed. Rosetta is the first spacecraft
to witness at close proximity how a comet changes as it is subjected to
the increasing intensity of the sun's radiation. Observations will help
scientists learn more about the origin and evolution of our solar system
and the role comets may have played in seeding Earth with water, and perhaps
even life.

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,
Gottingen; French National Space Agency, Paris; and the Italian Space
Agency, Rome. NASA's Jet Propulsion Laboratory, Pasadena, California,
a division of the California Institute of Technology in 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

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

Dwayne Brown
NASA 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

2015-214
Received on Fri 19 Jun 2015 10:17:49 PM PDT