[meteorite-list] MESSENGER Surpasses 200, 000 Orbital Images of Mercury

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 6 Feb 2014 17:19:18 -0800 (PST)
Message-ID: <201402070119.s171JIBm011342_at_zagami.jpl.nasa.gov>

http://messenger.jhuapl.edu/news_room/details.php?id=251
        
MESSENGER Mission News
February 6, 2014

MESSENGER Surpasses 200,000 Orbital Images of Mercury

MESSENGER has now returned more than 200,000 images acquired from orbit
about Mercury. The 1996 proposal for the mission promised a return of at
least 1,000 images says Robert Gold, MESSENGER's Science Payload
Manager. "We expected then that we would have some data compression that
would probably raise the image total to somewhere near 2,000 images,"
says Gold, of the Johns Hopkins University Applied Physics Laboratory
(APL), but scientists did not imagine then the degree to which MESSENGER
would surpass that goal.

"Returning over 200,000 images from orbit about Mercury is an impressive
accomplishment for the mission, and one I've been personally counting
down for the last few months," says APL's Nancy Chabot, the Instrument
Scientist for the Mercury Dual Imaging System (MDIS). "However, I'm
really more excited about the many thousands of images that are still in
MESSENGER's future, especially those that we plan to acquire at low
altitudes and will provide the highest resolution views yet of Mercury's
surface."

During MESSENGER's second extended mission, the spacecraft is making a
progressively closer approach to Mercury's surface with each successive
orbit. In about two months, each closest approach will be at a lower
altitude than at any previous point in the mission, enabling the
acquisition of unprecedentedly high-spatial-resolution data. For
spacecraft altitudes below 350 kilometers, Narrow Angle Camera (NAC)
images will be acquired with pixel scales ranging from 20 meters to as
little as 2 meters.

To commemorate the milestone, image scientists released this four-image
mosaic
<http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=1331>
-- one of the first from the MDIS low-altitude imaging campaign -- that
reveals, among other features, hollows that appear to have formed in one
layer in the wall of this 15-kilometer-diameter crater.

The mission marks three additional milestones today: the spacecraft
concludes its 12th Mercury year in orbit, its 18th Mercury sidereal day
in orbit, and its 6th Mercury solar day in orbit.

"We have come an incredible way since the first mission proposal was
submitted to NASA just over 17 years ago," notes MESSENGER Project
Scientist Ralph McNutt of APL. "Getting to launch and then to Mercury,
flyby by flyby, and into orbital operations were incredible
accomplishments -- against all sorts of odds -- and yet we are now,
almost routinely, noting these statistics about the mission that has
literally revealed an entirely new world to humanity."

When MESSENGER was launched in August 2004, he continues, "none of the
team in their wildest imagination could have foreseen the successes that
we now celebrate with new data coming back week by week from the
innermost planet. And we are not done. With a little more than a year
left to go, before gravity brings the end to operations, we will view
the planet and its environment from altitudes lower than were ever
envisioned only a few short years ago -- and, as with any planetary
mission providing closer and closer looks at a planetary neighbor, all
we can guess is that we have not wrung all of Mercury's surprises and
discoveries just yet."
------------------------------------------------------------------------
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and
Ranging) is a NASA-sponsored scientific investigation of the planet
Mercury and the first space mission designed to orbit the planet closest
to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and
entered orbit about Mercury on March 17, 2011 (March 18, 2011 UTC), to
begin a yearlong study of its target planet. MESSENGER's first extended
mission began on March 18, 2012, and ended one year later. MESSENGER is
now in a second extended mission, which is scheduled to conclude in
March 2015. Dr. Sean C. Solomon, the Director of Columbia University's
Lamont-Doherty Earth Observatory, leads the mission as Principal
Investigator. The Johns Hopkins University Applied Physics Laboratory
built and operates the MESSENGER spacecraft and manages this Discovery-
class mission for NASA.
Received on Thu 06 Feb 2014 08:19:18 PM PST