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MESSENGER Teleconference Multimedia Page

View more images taken by MESSENGER


Presenter #1
Eric J. Finnegan, MESSENGER Mission Systems Engineer
The Johns Hopkins University Applied Physics Laboratory

Image 1.1


This graphic depicts MESSENGER’s location when the Mercury Dual Imaging System (MDIS) took the first image from orbit about Mercury. The highly elliptical orbit was designed to accommodate the measurement needs of the science instruments while at the same time maintaining the health of the spacecraft. The initial injection orbital parameters are shown in the table, along with the allowable variations. The original periapse altitude was 207 kilometers (129 miles) and the apoapse was 15,261 kilometers (9,483 miles). In its current orbit, MESSENGER’s speed ranges from 0.573 km/s (1,282.8 mi/hr) to 3.77 km/s (8,439.7 mi/hr).

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Presenter #2
Sean C. Solomon, MESSENGER Principal Investigator
Carnegie Institution of Washington, Washington, D.C.

Image 2.1


This historic first orbital image of Mercury was acquired 37 years to the day after Mariner 10's historic first flyby of the innermost planet. Labels have been added to indicate several craters that were named on the basis of Mariner 10 images, as well as Debussy, Matabei, and Berkel, which were named on the basis of on MESSENGER flyby images. The surface area within the white lines is terrain previously unseen by spacecraft, and the star indicates the location of the south pole.

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

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Image 2.2


Bright rays, consisting of impact ejecta and secondary craters, spread across this NAC image and radiate from Debussy crater, located at the top. The image, acquired yesterday during the first orbit for which MDIS was imaging, shows just a small portion of Debussy's large system of rays in greater detail than ever previously seen. Images acquired during MESSENGER's second Mercury flyby showed that Debussy's rays extend for hundreds of kilometers across Mercury's surface. Debussy crater was named in March 2010, in honor of the French composer Claude Debussy (1862-1918).

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

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Image 2.3


The wide-angle camera (WAC) is not a typical color camera. It can image in 11 colors, ranging from 430 to 1020 nm wavelength (visible through near-infrared). It does this with a filter wheel: the 11 narrow-band filters (plus one clear filter) are mounted onto a wheel that can be rotated to allow the camera to capture an image through each filter. In this image the 1000 nm, 750 nm, and 430 nm filters are displayed in red, green, and blue, respectively. Several craters appear to have excavated compositionally distinct low-reflectance (brown-blue in this color scheme) material, and the bright rays of Hokusai crater to the north cross the image. During MESSENGER’s orbital operations, we will typically use just eight of the WAC's filters. This decision was made to reduce the amount of data that must be stored on the spacecraft’s solid-state recorder before the information can be downlinked. It’s also quicker than cycling through all 11 filters – the spacecraft is moving rapidly over the surface, and there isn't much time to image the same spot on the surface 11 times over before moving to the next area of interest. The sets of color images will help us learn about the variation in composition from place to place on the planet. For example, some minerals such as olivine and pyroxene often absorb more light at longer wavelengths than at shorter ones, so we’ll be looking for their signatures in the reflectance spectra derived from each eight-color set. WAC images will be used in coordination with the Mercury Atmospheric and Surface Composition Spectrometer (MASCS), a hyperspectral instrument that provides reflectance information at many more wavelengths, but only for one spot on the surface at a time.

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

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Image 2.4


This WAC image showing a never-before-imaged area of Mercury’s surface was taken from an altitude of ~450 km (280 miles) above the planet during the spacecraft’s first orbit with the camera in operation. The area is covered in secondary craters made by an impact outside of the field of view. Some of the secondary craters are oriented in chain-like formations.

This image was taken during MESSENGER’s closest approach to the sunlit portion of the surface during this orbit, just before crossing over the terminator. The oblique illumination by the Sun causes the long shadows and accentuates topography. The highly elliptical orbit of MESSENGER brings the spacecraft down to a periapsis (MESSENGER’s closest approach to Mercury) altitude of ~200 km (125 miles) and out to an apoapsis (MESSENGER’s farthest distance from Mercury) altitude of ~15,000 km (9300 miles).

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

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Image 2.5


Altimetric profiles obtained on 29 March during the first two successive MESSENGER orbits on which the Mercury Laser Altimeter (MLA) instrument was operating. Elevation is indicated by both the vertical scale and the color coding. The profile for the second orbit has been offset by 3 km for clarity. The profiles cross a variety of terrains, including a number of impact craters.

Credit: NASA/Goddard Space Flight Center/MIT/Johns Hopkins University Applied Physics Laboratory

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Image 2.6


This plot depicts measurements of the strength of Mercury's internal magnetic field measured on 10 successive MESSENGER orbits. Within 5 days, these observations tripled the number of measurements of the planetary field relative to the number available after all of the Mercury flybys by Mariner 10 and MESSENGER. Moreover, because of MESSENGER's orbit, the maximum magnitude of the measured field was greater than that seen during any of the spacecraft flybys. These observations are improving our knowledge of the geometry of Mercury's magnetic field, which will be key to understanding why Mercury has such a global field when the larger planets Mars and Venus do not.

Credit: NASA/Goddard Space Flight Center/Johns Hopkins University Applied Physics Laboratory

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