By Thomas Guengerich
SOCORRO, N.M., Feb. 2, 2009 – New Mexico Tech has won a small but exclusive contract with NASA to monitor a controlled lunar impact later this year.
Magdalena Ridge Observatory is one of 11 telescopes that will observe, interpret and analyze a mission to look for water on the moon. New Mexico Tech’s contract with NASA is for $30,000 for four or five months.
“We’re one of the smallest telescopes on this project, so we feel like we’re playing with the big boys,” Dr. Eileen Ryan said. “This is really exciting to be a part of this.”
The 2.4-meter telescope at Magdalena Ridge became operational in September 2008. This contract represents another success for the facility, which already has a NASA contract to track near-Earth objects.
The Apache Point Observatory in Cloudcroft, N.M., will also monitor the impacts. The other observatories involved include five in Hawaii, one in Arizona and three telescopes in orbit.
“If we find water, that’s a huge step toward lunar exploration,” she said. “I’m sure our new president would like that information before supporting any strategic plan about going to the moon.”
NASA solicited proposals for ground-based telescope support of the Lunar Crater Observation and Sensing Satellite, or LCROSS, spacecraft mission. Ryan, the director for the 2.4-meter optical telescope at New Mexico Tech, responded to the highly competitive call in collaboration with the Southwest Research Institute in Boulder, Colo.
Tech was one of a select few awarded funds in late December 2008. She and doctoral student Jed Rembold will spearhead the project at Magdalena Ridge Observatory. Dr. Bill Ryan, the telescope scientist and astrophysicist researcher at the observatory, will also play an integral role.
“This is a pretty big opportunity for the MRO,” Rembold said. “Some prestigious telescopes were chosen to work on this.”
Rembold earned his bachelor’s in math and physics from Linfield College in Oregon. Now in his second year as a doctoral student at New Mexico Tech, he had already been studying lunar impacts as his doctoral thesis. Using a 14” telescope near campus, he had been monitoring natural impacts on the moon, which occur about every three hours. He said this NASA projects fits perfectly with his research emphasis.
Astronomers suspect that water exists in the polar regions of the moon, but its presence is not certain. First, the LCROSS satellite will send a 4,400-pound projectile into a crater on the moon. After the first impact, the LCROSS satellite will self-destruct by making a kamikaze run at the moon. The impacts will create plumes of lunar materials. Scientists will monitor the impacts and subsequent plumes via optical and infrared light and spectrometers. The spectrometers will detect the chemical composition of the plumes and, hopefully, determine whether water exists.
“Finding water is the precursor to setting up human resources so we could live comfortably on the moon under artificial constructs,” Ryan said. “This mission will have a huge impact on where we go as a nation in the future.”
The two main components of the LCROSS mission are the Shepherding Spacecraft and the Centaur upper stage rocket. The Shepherding Spacecraft guides the rocket to a site selected on the moon that is suspected to contain ice. Because suspected deposits are concentrated in permanently-shadowed craters, the researchers have to be very precise where they program the Shepherding Spacecraft to guide the rocket, according to the NASA website.
The Shepherding Spacecraft and Centaur rocket will be launched with another spacecraft called the Lunar Reconnaissance Orbiter (LRO). All three will be connected to each other for launch, but then the LRO will separate about two hours after launch. The Shepherding Spacecraft will guide the Centaur rocket through multiple Earth orbits, each taking about 38 days. The rocket then will separate from the Shepherding Spacecraft and impact the Moon at more than twice the speed of a bullet, causing an impact that results in a big plume or cloud of lunar debris, and possibly water.
While this happens, the Shepherding Spacecraft will monitor and collect data on the rocket’s descent and impact. Four minutes later, the Shepherding Spacecraft will follow almost the exact same path as the rocket, descending down through the big plume and analyzing it with special instruments.
The launch window is from April to June. The optimum period for impact is from early August to mid-September. This impact will be so big that the resulting plume of material may be visible from Earth with a good amateur telescope.
After the event, Magdalena Ridge Observatory astrophysicists will deliver as much data as possible in real time for a NASA press conference planned just three hours after the impact. Then, Rembold, Ryan and Ryan will spend a few weeks on in-depth interpretation and analysis of the data before delivering a final report to NASA.
In addition to the 2.4-meter telescope, Rembold will also observe the impacts with a 14-inch telescope. The Southwest Research Institute will bring another 14-inch telescope to Socorro.
“We’re not sure how bright the plumes will be,” Eileen Ryan said. “The brightness depends largely on how much water vapor is in the plume and how big the plume will be.”
In addition to finding water, Rembold will use the findings to correlate the size of the plume to the size of the impacting object.
“Right now, there’s not very many good means of estimating the size of a meteor hitting the moon,” he said. “There hasn’t been a lot of work done scientifically about the exact correlation between brightness of the plume and size of the asteroid or meteor that smashes into the surface. With this mission, we know how big it is, so it will serve as a baseline for future impacts we see. We’ll be able to estimate how big they are. This is like a controlled meteor.”
– NMT –