MESSENGER's Mercury flyby science data now safely on Earth
Fri Jan 18, 2008 at 17:27 UTC
A day after its successful flyby of Mercury, the MESSENGER spacecraft turned toward Earth on Tuesday and began downloading the 500 megabytes of data that had been stored on the solid-state recorder during the encounter. All of those data, including 1,213 images from the Mercury Dual Imaging System (MDIS) cameras, have now been received by the Science Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.
Preliminary analysis of these data by the MESSENGER Science Team has confirmed that all seven MESSENGER instruments are healthy and operated as planned during the flyby.
As MESSENGER flew by the planet, it missed its targeted aim point by only 8.25 kilometers (5.12 miles), affording the critical gravity assist needed to continue on a course to become - in 2011 - the first spacecraft ever to orbit Mercury. During this first encounter, the payload successfully conducted a carefully orchestrated sequence of observations designed to take full advantage of the geometry of the flyby trajectory and to optimize the science return from each instrument.
In addition to images of the previously unseen portion of the planet's surface, measurements were made that will contribute to the characterization of all aspects of Mercury and its environment, from its metallic core to the far reaches of its magnetosphere. "We have one excited Science Team," says MESSENGER Project Manager, Peter D. Bedini, of APL, "and their enthusiasm is contagious."
The analysis of these data is just beginning, but there are already indications that new discoveries are at hand.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
High resolution image
This image was taken about 80 minutes before closest approach from a distance of about 27,000 kilometers (17,000 miles) and shows features as small as 10 kilometers (6 miles).
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
High resolution image
On January 14, 2008, the MESSENGER spacecraft observed about half of the hemisphere not seen by Mariner 10. These images, mosaicked together by the MESSENGER team, were taken by the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS) instrument, about 20 minutes after MESSENGER's closest approach to Mercury, when the spacecraft was at a distance of about 5,000 kilometers (about 3,100 miles). The image shows features as small as 400 meters (0.25 miles) in size and is about 370 kilometers (230 miles) across.
The image shows part of a large, fresh crater with secondary crater chains located near Mercury's equator on the side of the planet newly imaged by MESSENGER. Large, flat-floored craters often have terraced rims from post-impact collapse of their newly formed walls. The hundreds of secondary impactors that are excavated from the planet's surface by the incoming object create long, linear crater chains radial to the main crater. These chains, in addition to the rest of the ejecta blanket, create the complicated, hilly terrain surrounding the primary crater. By counting craters on the ejecta blanket that have formed since the impact event, the age of the crater can be estimated. This count can then be compared with a similar count for the crater floor to determine whether any material has partially filled the crater since its formation. With their large size and production of abundant secondary craters, these flat-floored craters both illuminate and confound the study of the geological history of Mercury.
| Source: Johns Hopkins University Applied Physics Laboratory | |
 |
More on • MESSENGER • Mercury |
