The event is the highlight of NASA's Lunar Crater Observation and Sensing Satellite (LCROSS) mission. The LCROSS spacecraft flies behind its empty upper stage, which is targeted to strike the floor of Cabeus crater. LCROSS will image the impact and provide direct measurements of the plume before it also plunges into the lunar surface. With LCROSS gone, further measurements of the cloud depend on ground-based observatories around the world.
"This is a completely unique mission that will excavate two large holes dozens of meters across on the lunar surface. It will give us composition measurements we wouldn't otherwise be able to get," said Tim McClanahan, a scientist at Goddard Space Flight Center in Greenbelt, Md.
McClanahan's modeling of the moon's permanently shadowed regions, initially done to support the Lunar Exploration Neutron Detector (LEND) instrument aboard NASA's Lunar Reconnaissance Orbiter (LRO), underscored a problem for ground-based follow-up of the LCROSS impact. "We realized that ground observers would have difficulty identifying the location," he said. "It's near the lunar south pole, where illumination is poor and the ability to distinguish nearly edge-on craters is problematic. On top of that, LCROSS will hit the crater floor, but we can only see its rim from Earth."
To provide the detailed information ground-based telescopes needed, McClanahan approached Goddard's Scientific Visualization Studio (SVS). The goal was to find a "sweet spot" where factors such as lunar topography, lighting from the sun, and the view from Earth provided the earliest, highest-contrast view of the rapidly changing plume.
"Visualization aided two aspects of the LCROSS mission," said Ernie Wright at the SVS. "It helped us understand how visible the plume will be from Earth and whether the targeted terrain was flat and in shadow."
The project prefers a crater floor because slopes tend to be rocky, whereas lighter, fluffier materials fall to the lowest elevations. "LCROSS scientists want to send up a debris cloud as high as they can," Wright explained, "so they want to hit these light materials."
Scientists think that hydrogen detected in lunar soil by several instruments, including LEND, may be either icy leftovers from ancient comet impacts or accumulated from the solar wind, a stream of particles flowing from the sun. Whatever its source, scientists assume hydrogen collects in low polar elevations where the sun never shines. This dictates an impact in the shadowed portion of a crater floor.
On September 11, LCROSS mission planners announced that they had targeted a smaller, more northerly crater named Cabeus A. But later that month, analyses of new data from instruments aboard LRO, together with archival measurements from NASA's Lunar Prospector mission of the late 1990s, indicated that the larger Cabeus crater was a better bet.
"The sweet spot for ground-based telescopes lies about two kilometers above the floor of Cabeus," Wright explained. "There, sunlight streaming through a depression in the crater rim will light up the plume while the rest of the crater remains in shadow."
Francis Reddy | EurekAlert!
Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald
Temperature-controlled fiber-optic light source with liquid core
20.06.2018 | Leibniz-Institut für Photonische Technologien e. V.
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Life Sciences
22.06.2018 | Physics and Astronomy
22.06.2018 | Earth Sciences