SMART-1 Impact Site on the Moon
“On the morning of 3 September 2006, a brief flash illuminated the Moon’s ‘Lake of Excellence’ as ESA’s SMART-1 mission met its fate on the dusty surface. Launched in 2003, SMART-1 was the first European spacecraft to travel to and orbit the Moon. Short for Small Missions for Advanced Research in Technology, SMART-1 used ion propulsion to journey to the Moon, tested new techniques in communications and navigation, and carried a battery of miniaturised scientific instruments. It completed a comprehensive inventory of key chemical elements in the lunar surface, mapped impact craters, studied the volcanic and tectonic processes that shaped the Moon, and investigated sites for future exploration.”
An odd-looking impact feature raises an intriguing, Apollo-era trivia question (3.02°S, 119.15°E). NAC image number M141485413; incidence angle 12°; Sun is from the east; north is up; image is ~600 meters across [NASA/GSFC/Arizona State University].
Lunar Orbiter 2 was an unmanned imaging spacecraft used in November and early December 1966 to aid with Apollo and Surveyor landing site selection. The spacecraft became famous in 1967 with the public release of an oblique image of Copernicus crater (one of only four obliques collected), which was hailed as the “Picture of the Century” by the news media of the day. According to the 2007 International Atlas of Lunar Exploration, the Lunar Orbiter 2 spacecraft was commanded to crash into the lunar farside surface on October 11, 1967.
The coordinates of the Lunar Orbiter 2 impact are given as 119.1° east longitude and 3.0° north latitude, which match those of the feature in the NAC image (measured at 119.149° east longitude, and 3.020° north latitude). However, the published Lunar Orbiter 2 numbers are given as a rough estimate because the impact occurred on the farside of the Moon, out of direct radio contact. So the match with the NAC coordinates could be a coincidence.
The impact appears much too large (~85 m in diameter) to be the result of an impact from a spacecraft only a few meters tall, but with a solar incidence angle of only 12 degrees, it is difficult to see the crater rim and find out the true diameter. Perhaps the ejecta pattern extends far beyond the immediate impact. The truth is that we are not sure what caused this impact feature. We are currently re-targeting the area under a higher incidence angle to help with crater rim measurements. Stay tuned!
The European Space Agency’s SMART-1 team has released an image of the future impact site of NASA’s Lunar Crater Observation and Sensing Satellite (LCROSS). LCROSS will search for water ice on the Moon by making two impacts into a crater named Cabeus A at the lunar South Pole. The impacts are scheduled for 11:30 am UT on 9 October 2009.
Bjoern Grieger, the liaison scientist for SMART-1’s AMIE camera, and Project Scientist Bernard Foing have searched through SMART-1’s database for images of Cabeus A, taken four years ago at conditions where solar elevation and direction were similar to those of LCROSS impact. The SMART-1 image is at high resolution as the spacecraft was at its closest distance of 500 km from the South Pole. The SMART-1 image of the LCROSS target was discussed last week at lunar sessions of the European Planetary Science Congress (EPSC) in Potsdam, Germany. More
This mosaic of images, obtained by the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft, shows the SMART-1 landing site on the Moon. AMIE obtained this sequence on 19 August 2006 from the relatively high distance of 1200 kilometres from the surface (far from the SMART-1 perilune, or point of closer approach), with a ground resolution of about 120 metres per pixel. The imaged area, located at mid-southern latitudes on the lunar near-side, belongs to the so-called ‘Lake of Excellence’. To take these images, SMART-1 had to be tilted by 20 degrees in order to obtain a large ground coverage and an image mosaic of several views, each covering an area about 60 kilometres per side. More