Thursday, July 2. 2009
The Lunar Reconnaissance Orbiter is performing exceptionally well and spacecraft checkout is proceeding smoothly. In fact, checkout is proceeding so smoothly that LROC was given an early, but short (two orbits) opportunity Tuesday to measure temperatures and background values while imaging. Since LRO is in a terminator orbit, much of the area photographed was in shadows, which is actually a good situation for performing engineering checks of camera settings. Much to the delight of the LROC Team, a few of the images captured dramatic views of the surface. Browse the whole NAC image!
What is summed mode? Along the terminator, there simply is not much light – the instrument is “photon-starved,” resulting in suboptimal signal-to-noise ratios. Or, to put it another way, without summing, images taken in this circumstance would be underexposed. To compensate for low light levels, we can effectively make the pixels larger by summing adjacent pixels to increase the signal-to-noise ratio, making the image sharper, though with 2x lower resolution. Browse the whole NAC image!
At this resolution, features as small as three meters wide can be discerned. You see here a starkly beautiful region a few kilometers east of Hell E crater, which is located on the floor of the ancient Imbrian-aged Deslandres impact structure in the lunar highlands south of Mare Nubium. Numerous small, secondary craters can be identified, including several small crater chains. Also identifiable are distinctive lineations made readily apparent by the lighting conditions, which are probably remnants of a catastrophic deposition of ejecta from a nearby impact. The quality of these early engineering test images gives us confidence that the LROC Science Team can achieve our primary goals, including obtaining the data needed to support future human lunar exploration and utilization.
The best is yet to come! Once LRO finishes commissioning operations and enters its 50-km x 50-km mapping orbit, a maneuver currently scheduled for mid-August, the LROC NAC will take images over 8% of the Moon at 50-cm/pixel.
LROC WAC: Seeing the colors of the Moon
Raw WAC image of the Deslandres region showing the WAC's native "ventian blind" effect. Representative width of one of our early NAC images is shown as two vertical bars in the center. Image is about 90 km wide; north is down [NASA/GSFC/Arizona State University].
LROC is scheduled for activation on Friday July 3rd to formally begin its commissioning activities. The LROC Science Operations Center plans to steadily release exciting images of the lunar frontier as more data is collected and processed.
LRO will spend the next year gathering crucial data on the lunar environment that will help astronauts prepare for exploring the Moon and eventually leaving the Earth-Moon system for voyages to Mars and beyond.