Showing posts with label Mercury. Show all posts
Showing posts with label Mercury. Show all posts

Thursday, July 3, 2014

Mercury's Terminator


Today's color image features both Mercury's terminator and limb. The terminator is the striking separation of night and day on Mercury. It is seen in this image with the change from dark, on the left of the image, to light. Mercury's limb is also captured, as we can see the edge between sunlit Mercury and space.

Date acquired: May 05, 2014
Image Mission Elapsed Time (MET): 41602341, 41602337, 41602335
Image ID: 6252070, 6252068, 6252067
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: -57.08°
Center Longitude: 93.92° E
Resolution: 3227 meters/pixel
Scale: The bottom edge of this image is approximately 2530 km (1572 miles) in length.

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

Wednesday, June 11, 2014

Mercury Transit of the Sun, as Seen from Mars


This animated blink comparison shows five different versions of observations that NASA's Curiosity made about one hour apart while Mercury was passing in front of the sun on June 3, 2014. Two sunspots, each about the diameter of Earth, also appear in the images, moving much less during the hour than Mercury's movement.

This is the first observation of any planet's transit of the sun observed from any planet other than Earth. It is also the first observation of Mercury from Mars.

With precise information about when the transit would occur, the rover team planned this observation using the telephoto-lens (right-eye) camera of Curiosity's Mast Camera (Mastcam) instrument. The camera has solar filters for routine observations of the sun used for assessing the dustiness of the atmosphere. Mercury appears as a faint darkening that moves across the face of the sun. It is about one-sixth the size of a right-Mastcam pixel at the interplanetary distance from which these images were taken, so it does it does not appear as a distinct shape, but its position follows Mercury's known path.

Each of the five versions of the image presented here blinks back and forth between two views recorded at different times during the transit. North is up. The version on the left is minimally enhanced, for a natural looking image of the sun with two sunspots barely visible. The second version has limb darkening removed, the edges masked. The third has enhanced contrast. The fourth has a line added to indicate the calculated path of Mercury during the transit. The fifth adds annotation to point out which spot is Mercury (in the cross hairs) and to identify two sunspots.

For a video presentation of these images, see http://www.jpl.nasa.gov/video/?id=1309.

Transits of the sun by Mercury and Venus, as seen from Earth, have significant history. Observations of Venus transits were used to measure the size of the solar system, and Mercury transits were used to measure the size of the sun.

Image credit: NASA/JPL-Caltech/MSSS/Texas A&M

Note: For more information, see Mercury Passes in Front of the Sun, as Seen From Mars.

Saturday, March 22, 2014

Mercury by Messenger's MASCS and VIRS Instruments


The Sun's light provides a powerful tool for understanding the composition of materials in the Solar System. Today's image features two views of Mercury provided by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument. As the Sun's light hits the surface of Mercury, the Visible and Infrared Spectrograph (VIRS) portion of MASCS measures many wavelengths of the reflected light from a single spot on the surface at a time. These observations create a spectral profile of the surface as MESSENGER orbits Mercury. In each panel, the top left corner of the image is 70°N,180°E and the bottom right corner is 70°S,180°E. Most of Caloris basin can be seen along the right edge of each panel. The top panel is a monochromatic image of the interpolated 750 nm reflectance, and the bottom panel shows the same data but in a false color composite selected to highlight compositional variations on the surface.

The monochromatic map is part of a data set that was released to the public earlier this month through the Planetary Data System (PDS). In conjunction with the release, the team hosted a Data User's Workshop at the 45th Lunar and Planetary Science Conference, which is being held this week in The Woodlands, Texas.

Instruments: Visible and Infrared Spectrograph (VIRS) of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS)
Center Latitude: 0°
Center Longitude: 0° E
Map Projection: Simple Cylindrical
VIRS Monochromatic Wavelength: 750 nm
VIRS Color Composite Wavelengths: 575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue
Scale: Caloris Basin is 1,550 km (963 mi) across.

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

Tuesday, January 28, 2014

Impact Craters in Rasditladi Quadrant


If absence makes the heart grow fonder, then many on the MESSENGER team are now really fond of MDIS images! It has been over two months since the MESSENGER spacecraft returned images of Mercury's surface through routine downlink operations. Shown here is one of the last images sent before the two month gap. The lack of images is due to a very logical explanation: Mercury (and hence the MESSENGER spacecraft) has been on the opposite side of the Sun from the Earth, limiting the amount of data that can be downlinked. Generally, MDIS images take up more room than the data from MESSENGER's other instruments, so MDIS images are downlinked last, after all other instrument data are down. Happily, the distance between Mercury and the Earth is now decreasing; check out where both planets are today. Soon, we'll again have new images of Mercury's surface!

This image was acquired as part of MDIS's high-incidence-angle base map. The high-incidence-angle base map complements the surface morphology base map of MESSENGER's primary mission that was acquired under generally more moderate incidence angles. High incidence angles, achieved when the Sun is near the horizon, result in long shadows that accentuate the small-scale topography of geologic features. The high-incidence-angle base map was acquired with an average resolution of 200 meters/pixel.

Date acquired: November 20, 2013
Image Mission Elapsed Time (MET): 27234508
Image ID: 5230158
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 44.20°
Center Longitude: 223.3° E
Resolution: 150 meters/pixel
Scale: This image is roughly 280 km (170 miles) across
Incidence Angle: 60.6°
Emission Angle: 55.0°
Phase Angle: 30.0°

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

Note: This image is located near the center of Raditladi Quadrant; the closest named feature to this image is Nawahi Crater, which is some distance to the east.

Wednesday, January 1, 2014

Messenger's 2013 Year in Review


The year 2013 has been another year of operations and discoveries for MESSENGER, finally including 100% image coverage of the planet by the Mercury Dual Imaging System (MDIS)! As another year draws to a close, we look back at some of the featured images from the year, and look forward to continued operations, including some of the highest-resolution images ever taken of Mercury, in 2014!

• January: They Call Me Muddy Waters
• February: Colors of the Innermost Planet
• March: A Colorful Group
• April: An Unnamed Wonder
• May: 100% Coverage
• June: It's a Sublimation Formation!
• July: Digital Elevation Model of Mercury's Northern Hemisphere
• August: Peek-a-boo!
• September: A Volcanic View
• October: Degas' Impression
• November: A Late Holloween
• December: On the Horizon

You can also revisit previous yearly compilations from 2008, 2009, 2010, 2011, and 2012.

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

Tuesday, November 5, 2013

New Quadrangle Maps of Mercury


A new set of Mercury maps are available on the USGS website. These maps utilize the current best MESSENGER mosaic of Mercury, which covers 100% of the surface. Mercury's surface is divided into 15 different quadrangles. The H-10 quadrangle, which is named for the crater Derain, is shown here at half the available resolution. For the full resolution map of this region, and all of Mercury's surface, visit the USGS website.

Map Quadrangles: H-10 Derain
Center Latitude: 0°
Center Longitude: 36° E (324° W)
Scale: Derain has a diameter of 167 km (104 miles)
USGS Maps of Mercury website: http://planetarynames.wr.usgs.gov/Page/mercuryQuadMap

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

Saturday, November 2, 2013

Crescent Mercury


Although its geologic history was very different from that of our closest celestial neighbor, it's fun to see Mercury in the familiar crescent we associate with the Moon. Though the extreme viewing angle makes it hard to tell, this irregular pit is near the center of the sunlit sliver.

This image was acquired as part of MDIS's limb imaging campaign. Once per week, MDIS captures images of Mercury's limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury's shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere.

Date acquired: October 09, 2013
Image Mission Elapsed Time (MET): 23631997
Image ID: 4974136
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -53.19°
Center Longitude: 121.8° E
Resolution: 655 meters/pixel
Incidence Angle: 96.8°
Emission Angle: 67.9°
Phase Angle: 140.3°

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

Thursday, October 31, 2013

Mercurial Limb, One Week Later


What a difference a week makes. Today's featured image was acquired earlier this month, one week after this image (PIA17579), showing how the lighting conditions change in an Earth week (but only about 4% of a Mercury day). Can you spot the crater with the prominent secondary chains? With the Sun now a bit higher above this crater (located about a quarter of the way up from the bottom of the frame), its floor appears smooth, and its crater chains can still be seen to stretch far from its rim.

This image was acquired as part of MDIS's limb imaging campaign. Once per week, MDIS captures images of Mercury's limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury's shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere.

Date acquired: October 09, 2013
Image Mission Elapsed Time (MET): 23629938
Image ID: 4974132
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -43.49°
Center Longitude: 150.4° E
Resolution: 1085 meters/pixel
Incidence Angle: 77.7°
Emission Angle: 57.7°
Phase Angle: 132.9°

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

Tuesday, October 29, 2013

Mercurial Limb


Another day, another beautiful view of Mercury's horizon. In this scene, which was acquired looking from the shadows toward the sunlit side of the planet, a 120-km (75 mile) impact crater stands out near the center. Emanating from this unnamed crater are striking chains of secondary craters, which gouged linear tracks radially away from the crater. While this crater is not especially fresh (its rays have faded into the background), it does appear to have more prominent secondary crater chains than many of its peers.

This image was acquired as part of MDIS's limb imaging campaign. Once per week, MDIS captures images of Mercury's limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury's shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere.

Date acquired: October 02, 2013
Image Mission Elapsed Time (MET): 23055902
Image ID: 4933174
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -52.13°
Center Longitude: 167.5° E
Resolution: 667 meters/pixel
Incidence Angle: 82.0°
Emission Angle: 69.4°
Phase Angle: 122.4°

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

Saturday, July 27, 2013

Impact Craters in Mercury's Southern Hemisphere


This image of Mercury's southern hemisphere shows the large size variation and multiple generations of impact craters on Mercury. Mercury's southern hemisphere is easier to image due to MESSENGER's elliptical orbit, but this orbit also prevents acquisition of high resolution images like those taken in the northern hemisphere.

Date acquired: February 08, 2013
Image Mission Elapsed Time (MET): 2613780
Image ID: 3479116
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 9 (996 nanometers)
Center Latitude: -80.38°
Center Longitude: 302.4° E
Resolution: 1486 meters/pixel
Scale: The complex crater in the center of the image is 151 km in diameter (94 miles).
Incidence Angle: 85.0°
Emission Angle: 25.8°
Phase Angle: 59.1°

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

Friday, July 19, 2013

Enhanced Color Map of Mercury


This colorful view of Mercury is similar to that used to generate this movie [23MB, 6.5MB] of Mercury as a spinning globe, and these two individual views (centered at 140°E and 320°E) of the innermost planet. The enhanced color view is overlaid on the global monochrome base map, which is available for download here.

The enhanced color was produced by using images from the color base map imaging campaign during MESSENGER's primary mission. These colors are not what Mercury would look like to the human eye, but rather the colors enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury's surface. This specific color combination places the second principal component in the red channel, the first principal component in the green channel, and the ratio of the 430 nm/1000 nm filters in the blue channel.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 0°
Center Longitude: 180° E
Map Projection: Simple cylindrical projection
Resolution: 3.74 km/pixel
Scale: Mercury's diameter is 4880 kilometers (3030 miles)

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

Thursday, July 18, 2013

Digital Elevation Model of Mercury's Northern Hemisphere


The above image is from a digital elevation model (DEM) created by using orbital MLA data. The colors illustrate Mercury's topography, which spans roughly from -5 km (deep blue) to 5 km (red). The specific color bar is given on the ACT-REACT QuickMap description of this DEM layer. Also in QuickMap, this DEM can be used to generate 3D views of the surface.

The DEM can be downloaded on MESSENGER's Global Mosaics of Mercury webpage in a variety of formats and resolutions. The DEM was created by using MLA orbital data through that released by the PDS on March 8, 2013. Due to MESSENGER's highly elliptical orbit, MLA can only range to the surface in the northern hemisphere. Consequently, the DEM products derived from MLA data only cover the northern hemisphere of Mercury. Additionally, the accuracy of each DEM product is higher closer to the north pole, and near the equator, the data are highly interpolated.

Instrument: Mercury Laser Altimeter (MLA)
Center Latitude: 90° N
Map Projection: Polar stereographic projection, extending southward to 55° N, with 0° longitude at the bottom
Resolution: 2 km/pixel
Scale: The distance across the center of this polar map projection is approximately 2,980 kilometers (1850 miles)
Download: Global Mosaics of Mercury Webpage

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

Friday, March 15, 2013

A Tribute to Messenger


This video showcases a small sampling of the thousands of images taken by the spacecraft, as well as animations illustrating how MESSENGER moves in orbit and how its orbit has changed during the mission.

The opening sequence is from the approach images from the first flyby in 2008. The first animation to follow (at 0:15) shows MESSENGER in its primary mission 12-hour orbit. The relevance of the November 9, 2011, date is that this was when the MESSENGER team was advised that NASA had approved the proposal for an extended mission, allowing the mission to continue making new observations from March 2012 to March 2013. The animation at 0:22 gives you an idea of the movement and gyrations ("dancing") that the spacecraft undergoes while it performs a schedule packed full of observations that take place over one Earth day. The animation sequence at 0:59 gives you a "top down" view over Mercury's north pole from when MESSENGER first went into orbit until several months into the extended mission. The apparent size of the orbit shrinks from the start of the animation to the end, as shortly into the extended mission, MESSENGER's orbital period was shrunk from 12-hours to 8-hours. The animation sequence at 1:44 shows MESSENGER's "dance" on the first day of the extended mission. The other images and embedded movies can be found in the Gallery section of the MESSENGER website.

Some highlight images of note include:

At 0:48 - Blue rays of Bek crater
At 0:54 - Basho crater
At 0:57 - Poe crater in Caloris basin
At 1:17 - MASCS instrument surface scans in ultraviolet and infrared
At 1:19 - A perspective view of the northern polar region, color-coded to MLA topography
At 1:27 - Rembrandt impact basin
At 1:29 - Rembrandt impact basin superimposed on the US for size comparison
At 1:34 - Rachmaninoff impact basin, 3D effect crated using the digital elevation model
At 1:34 - Debussy crater
At 1:58 - Beagle rupes
At 2:04 - Mosaic view of north pole, showing the shadowed regions
At 2:06 - As previous, with superimposed radar data indicating likely water-ice deposits
At 2:11 - A volcanic vent near the edge of Caloris basin
At 2:34 - Derain crater
At 2:36 - Disney crater and two unnamed craters that resemble Mickey Mouse
At 2:38 - Basho crater while the Sun is low in the sky
At 2:40 - Basho crater again, but now with the Sun nearly overhead
At 2:45 - Degas crater
At 2:58 - 'Weird terrain' at the Caloris antipode
At 3:03 - Waters crater with the 'blue tongue' of dark impact melt material
At 3:10 - Seuss crater
At 3:13 - Caloris basin
At 3:15 - Pit in Scarlatti crater, with prominent hollows on the pit rim
At 3:17 - Enhanced color of Caloris basin
At 3:22 - A lava channel that had flowed into the Kofi crater
At 3:29 - More detail of Caloris basin floor
At 3:30 - The young, bright-rayed Mena crater
At 3:37 - Central peaks of Eminescu crater, with hollows around the bases of the peaks
At 3:39 - Apollodorus and Pantheon fossae
At 3:41 - The hollows on the floor of Sander crater

The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MDIS acquired 88,746 images and extensive other data sets. MESSENGER is now in a year-long extended mission, during which plans call for the acquisition of more than 80,000 additional images to support MESSENGER's science goals.

Video credit: Images and animation stills courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington. Music: "Mercury Ridge" by Simon Wilkinson (thebluemask.com). Video creation and time-lapse animations by Mark 'Indy' Kochte.

Sunday, February 24, 2013

Mercury


The view shown here is similar to an earlier one, posted in October 2011, but now the coverage is more complete. The globe on the left was created from the MDIS monochrome surface morphology base map campaign. The globe on the right was produced from the MDIS color base map campaign. Each map is composed of thousands of images, and the color view was created by using 3 of the 8 color filters acquired. (1000, 750, and 430 nm wavelengths are displayed in red, green, and blue, respectively.) On March 8, 2013, these global maps will be publicly released at full resolution by NASA's Planetary Data System.

Instrument: Mercury Dual Imaging System (MDIS)
Center Latitude: 0°
Center Longitude: 75° E
Scale: Mercury's diameter is 4880 kilometers (3030 miles).
Map Projection: orthographic

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

Thursday, February 21, 2013

Mercury's Limb Near the Caloris Basin


This striking view is located near the rim of the large Caloris basin. The rim of Caloris is marked by hills and mountains, some of which can be seen in the distance in this image.

This image was acquired as part of MDIS's limb imaging campaign. Once per week, MDIS captures images of Mercury's limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury's shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere.

Date acquired: December 18, 2012
Image Mission Elapsed Time (MET): 264299214
Image ID: 3161641
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 6°
Center Longitude: 149° E
Additional Location Information: The mountain on the horizon on the left side of the image is at roughly 13°, 152° E
Scale: The bottom of this image is about 210 kilometers (130 miles) across.

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

Wednesday, February 20, 2013

Mercury, Enhanced (2)


This colorful view of Mercury was produced by using images from the color base map imaging campaign during MESSENGER's primary mission. These colors are not what Mercury would look like to the human eye, but rather the colors enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury's surface.

Young crater rays, extending radially from fresh impact craters, appear light blue or white. Medium- and dark-blue areas are a geologic unit of Mercury's crust known as the "low-reflectance material", thought to be rich in a dark, opaque mineral. Tan areas are plains formed by eruption of highly fluid lavas. The crater in the upper right whose rays stretch across the planet is Hokusai.

To see the other side of the planet view this image.

To watch a movie of this colorful view of Mercury as a spinning globe click here or visit the mission's Movie Page.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 0°
Center Longitude: 320° E
Scale: Mercury's diameter is 4880 kilometers (3030 miles)
Map Projection: orthographic

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

Tuesday, February 19, 2013

Mercury, Enhanced (1)


This colorful view of Mercury was produced by using images from the color base map imaging campaign during MESSENGER's primary mission. These colors are not what Mercury would look like to the human eye, but rather the colors enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury's surface.

Young crater rays, extending radially from fresh impact craters, appear light blue or white. Medium- and dark-blue areas are a geologic unit of Mercury's crust known as the "low-reflectance material", thought to be rich in a dark, opaque mineral. Tan areas are plains formed by eruption of highly fluid lavas. The giant Caloris basin is the large circular tan feature located just to the upper right of center of the image.

To see the other side of the planet view this image.

To watch a movie of this colorful view of Mercury as a spinning globe click here or visit the mission's Movie Page.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 0°
Center Longitude: 140° E
Scale: Mercury's diameter is 4880 kilometers (3030 miles)
Map Projection: orthographic

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

Saturday, February 16, 2013

Mercury Global Map


A global color map of Mercury's surface has been created by mosaicking thousands of sets of images obtained by the MESSENGER Wide Angle Camera (WAC). The colors shown here are related to variations in the spectral reflectance across the planet. This view captures both compositional differences and differences in how long materials have been exposed at Mercury's surface. Young crater rays, arrayed radially around fresh impact craters, appear light blue or white. Medium- and dark-blue areas are a geologic unit of Mercury's crust known as the "low-reflectance material," thought to be rich in a dark, opaque mineral. Tan areas are plains formed by eruption of highly fluid lavas. The large circular area near the top center is the Caloris impact basin, whose interior is filled with smooth, somewhat younger volcanic plains. Small orangish spots are materials deposited by explosive volcanic eruptions.

The color base map shown here consists of MDIS images taken through eight different color filters. It is part of a global color map that covers more than 99% of Mercury's surface with an average resolution of about 1 kilometer per pixel.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS). This is an enhanced-color presentation created from a statistical combination of images taken through eight of the WAC filters.

Video credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington; text credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Note: Available on the original NASA webpage are two different size maps available for download: a smaller 6.5 MB video and a larger 23 MB video.

Tuesday, May 1, 2012

Mercury Spectral Reflectance Map


This sinusoidal equal area projection map shows a color composite of Mercury spectral reflectance observed by the MASCS VIRS instrument over the MESSENGER primary mission. VIRS footprint tracks are RGB-colored where red is brightness at 575 nm; green is the visible to infrared brightness ratio (415 nm / 750 nm); and blue is the ultraviolet to visible ratio (310 nm / 390 nm).

Broad regional differences and local areas of interest stand out with combinations of ratio and brightness values that give clues to mineralogical composition. Younger surface materials that are brighter at visible wavelengths and less affected by the processes of space weathering show up in reds, yellows and greens. Materials that may have relatively higher iron contents (though still very low relative to most lunar or terrestrial crustal rocks) show up in blues.

In locations where multiple VIRS footprints cover the same area, the footprint with the best illumination for mineralogical interpretation (usually the lowest incidence angle where shadows are minimized) is used for making the map.

Date Created: April 10, 2012
Instrument: Visible and Infrared Spectrograph (VIRS) of the MESSENGER Atmosphere and Surface Composition Spectrometer (MASCS)
Center Latitude: 0°
Center Longitude: 0° E
Resolution: 16 km/pixel

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

Friday, April 20, 2012

Spectral Map of Mercury


This sinusoidal equal area projection map shows the ground coverage on Mercury by the MASCS VIRS instrument. The coverage tracks are shaded by brightness measured by VIRS at 750 nm. A pixel is counted as 'observed' if any portion of it is covered by a VIRS footprint. By this method, over 81% of the surface has been observed in the primary mission of MESSENGER, with more to come in the extended mission. In locations where multiple VIRS footprints cover the same area, the footprint with the best viewing geometry (usually the lowest incidence angle) is counted for coverage, and for making spectral maps of the surface. These spectral maps are helping the MESSENGER team understand the composition and mineralogy of Mercury's surface.

Date Created: April 2, 2012
Instrument: Visible and Infrared Spectrograph (VIRS) of the MESSENGER Atmosphere and Surface Composition Spectrometer (MASCS)
Center Latitude: 0°
Center Longitude: 0° E
Resolution: 20 km/pixel

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