PIA10183: First Results from the Mercury Laser Altimeter

First Results from the Mercury Laser Altimeter


On January 14, 2008, MESSENGER's Mercury Laser Altimeter (MLA) became the first instrument to measure the distance between a spacecraft and the surface of Mercury. MLA operates by first firing a brief laser pulse at the surface. It then measures the time for the pulse to reach the surface and return to the spacecraft, thereby providing a precise distance.

This figure shows the distance, or range, from the MESSENGER spacecraft to the surface of Mercury as measured by MLA during the flyby of Mercury. The instrument acquired the surface at a slant range of about 600 kilometers (about 370 miles) and tracked the surface through closest approach near 200 kilometers (about 125 miles) and out to a distance of about 1500 kilometers (about 930 miles). During the Mercury encounter, the instrument met or exceeded all performance specifications. The MESSENGER team is continuing to process the MLA data, and the final results should enable distances to be measured to better than a meter, allowing the profiles of craters and other features to be measured.

The vertical exaggeration in the figure is about 5:1. The MLA was designed and built at the NASA Goddard Space Flight Center.

Background Info:

These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy .

Cataloging Keywords:

Name Value Additional Values
Target Mercury
System Mercury
Target Type Planet
Instrument Host MESSENGER
Host Type Orbiter
Instrument Mercury Laser Altimeter (MLA)
Extra Keywords Color, Crater
Acquisition Date
Release Date 2008-01-19
Date in Caption 2008-01-14
Image Credit NASA/Goddard Space Flight Center/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Source photojournal.jpl.nasa.gov/catalog/PIA10183
Identifier PIA10183