MESSENGER 2011 - A Year in Review

As we prepare to bid farewell to 2011, the MESSENGER spacecraft is now nine months into its orbital mission. The scientific products that MESSENGER has returned have given planetary scientists and space enthusiasts around the world a chance to better understand Mercury's formation, surface composition, and unique atmosphere-magnetosphere system. The Mercury Dual Imaging System (MDIS) has captured >99.9% of Mercury's surface in high resolution, including previously unseen terrain. As the mission moves forward into 2012, we are excited to continue to unravel the mysteries of this planet of extremes. Let's take a look back at some of this year's highlights:

January: Are we there yet?
February: Getting closer... A Solar System Family Portrait, from the Inside Out (second row)
March: Mercury Orbit Insertion! First Image Ever Obtained from Mercury Orbit (top left)
April: X Marks the Spot (top middle)
May: Another Look at Atget (top right)
June: What Happens in Degas Stays in Degas (bottom left)
July: Memories of Many Mixed Materials (third row, middle)
August: A Crater in CloseUp (third row, left)
September: Stunning Landforms in Raditladi Basin (third row, right)
October: The First Solar Day (fourth row, left)
November: Hurrah for the Red and the Blue (fourth row, right)
December: The Bright Rays of Mena (bottom middle), and Mercury Globe: North Pole (bottom right)

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Inside Eminescu Crater

This oblique view shows a portion of the rim of the crater Eminescu. The angle of this image provides a great perspective for viewing the spectacular cliffs that formed as material slumped from the crater rim into the crater interior, as well as small ponds of impact melt perched on the rim. North is down in this image.

Date acquired: December 05, 2011
Image Mission Elapsed Time (MET): 231611014
Image ID: 1099316
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 9.8°
Center Longitude: 115.5° E
Resolution: 34 meters/pixel
Scale: The scene is approximately 35 km (22 miles) from north to south.
Incidence Angle: 65.1°
Emission Angle: 60.1°
Phase Angle: 125.3°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

When the Going Gets Weird, the Weird Turn Pro

This view is a close-up of an area featured in a previous Gallery image. The region is located diametrically opposite the Caloris impact basin, and has been affected by converging seismic waves or ejecta that caused the peculiar "hilly and lineated" texture. Members of the Mariner 10 team informally called this the "weird terrain" when it was first discovered in 1974.

Date acquired: August 02, 2011
Image Mission Elapsed Time (MET): 220756231
Image ID: 581158
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -29.92°
Center Longitude: 342.0° E
Resolution: 235 meters/pixel
Scale: The scene is about 248 km (155 mi.) across.
Incidence Angle: 85.4°
Emission Angle: 19.3°
Phase Angle: 104.7°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

A Small Pond

This image shows a small pond of impact melt that was ejected from a crater just out of view. The melt ponded in this low, forming a smooth surface similar to the melt ponds south of Kuiper crater. North is toward the upper right corner.

Date acquired: November 06, 2011
Image Mission Elapsed Time (MET): 229105038
Image ID: 980525
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 63.9°
Center Longitude: 256.5° E
Resolution: 16 meters/pixel
Scale: The smooth region is approximately 3 km (1.9 miles) across
Incidence Angle: 69.5°
Emission Angle: 15.6°
Phase Angle: 85.2°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Rays of Light Material

The ejecta of this fresh 20-km impact crater swept the surface, leaving beautiful bright rays. Crater rays fade with time as smaller impacts mix them into the surrounding soil and particles from the solar wind change the surface's chemistry. Given a little time (perhaps a million years or so), this crater will look like the other similar-sized craters in the frame.

Date acquired: November 17, 2011
Image Mission Elapsed Time (MET): 230018573
Image ID: 1023529
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -51.0°
Center Longitude: 175.1° E
Resolution: 221 meters/pixel
Scale: The rayed crater is approximately 20 km (12 miles) in diameter
Incidence Angle: 53.1°
Emission Angle: 37.8°
Phase Angle: 78.6°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Fram Rupes

One hundred years ago, on December 14, 1911, Norwegian explorer Roald Amundsen and his party became the first people to reach the Earth's south pole. The name of the ship that carried Amundsen to Antarctica was the Fram. The image above shows a portion of Fram Rupes on the planet Mercury, a long scarp (cliff) formed by compressive forces generated as the planet's interior cooled and contracted.

Date acquired: November 06, 2011
Image Mission Elapsed Time (MET): 229066087
Image ID: 978519
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -55.5°
Center Longitude: 267.8° E
Resolution: 152 meters/pixel
Scale: The edges of the image are about 157 km long.
Incidence Angle: 67.2°
Emission Angle: 14.9°
Phase Angle: 81.2°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

The Bright Rays of Mena

The young rays of Mena crater contrast brightly against the surrounding surface, though the rays will gradually fade with time. The asymmetric pattern of the rays, with a gap in the south-western direction, may be due to the angle at which the impact that formed the crater occurred, or to the fact that Mena formed on the rim of a larger pre-existing impact crater, as seen in this image.

Date acquired: November 12, 2011
Image Mission Elapsed Time (MET): 229581348, 229581352, 229581356
Image ID: 1003074-1003076
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (1000, 750, 430 nanometers) as red, green, blue
Center Latitude: -0.97°
Center Longitude: 234.0° E
Resolution: 257 meters/pixel
Scale: Mena has a diameter of 15 km (9 miles)
Incidence Angle: 29.7°
Emission Angle: 16.3°
Phase Angle: 46.0°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington