Close-up view of Apollo 12 landing site from LRO. Credit: NASA/GSFC/Arizona State University
Wow! Just look at the detail visible in this image of the Apollo 12 landing site taken by the Lunar Reconnaissance Orbiter from its lower mapping orbit of 50 km above the surface. Compared to earlier images taken in September when LRO was in a higher orbit, the Lunar Module descent stage really stands out, as well as the Apollo Lunar Surface Experiment Package (ALSEP). Also visible are the trails left by spacewalking astronauts. From this and other LROC landing site images, it is clear that astronaut activity lowers the albedo, or reflectivity of the surface. Areas of heaviest activity have the lowest albedo, especially around the LM. NASA says this effect is most likely due to compaction of a very loose surface powder by the astronauts just walking around.
The Apollo 12 landing site as seen by LRO. Credit: NASA/GSFC/Arizona State University
Here is a slightly more zoomed out version that includes the Surveyor 3 spacecraft. The Sun is very high in the sky (incidence angle 4°) for these images and shadows are minimized.
Below is an image taken by the astronauts as they set up the ALSEP instruments.
The Apollo 17 Lunar Module Challenger descent stage comes into focus from the new lower 50-km mapping orbit, image width is 102 meters [NASA/GSFC/Arizona State University].
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The Lunar Reconnaissance Orbiter maneuvered into its 50-km mapping orbit on September 15, which enables it to take a closer look at the Moon than any previous orbiter. This also allows for comparing previous images taken by LRO when it was at its higher orbit. Here’s the Apollo 17 landing site: just look at what is all visible, especially in the image below! These images have more than two times better resolution than the previously acquired images.
Region of Taurus-Littrow valley around the Apollo 17 landing site. NASA/GSFC/Arizona State University.
At the time of this recent pass, the Sun was high in the sky (28° incidence angle) helping to bring out subtle differences in surface brightness. The descent stage of the lunar module Challenger is now clearly visible, at 50-cm per pixel (angular resolution) the descent stage deck is eight pixels across (four meters), and the legs are also now distinguishable. The descent stage served as the launch pad for the ascent stage as it blasted off for a rendezvous with the command module America on December 14, 1972.
Also visible is the ALSEP, the Apollo Lunar Surface Experiments, which for Apollo 17 included 1) Lunar Seismic Profiling Experiment (geophones), 2) Lunar Atmospheric Composition Experiment (LACE) to measure the composition of the Moon’s extremely tenuous surface bound exosphere, 3) Lunar Ejecta and Meteorites (LEAM) experiment, 4) central station, 5) Heat Flow Experiment, 6) all powered by a Radioisotope Thermoelectric Generator (RTG). Below is how it looked from the surface, taken by the Apollo astronauts.
View of the ALSEP looking south-southeast. Credit: NASA
Compare these most recent images to one taken previously.
Zoomed in image of the impact plume. The extent of the plume at 15 sec is approximately 6-8 km in diameter. Credit: NASA
Nine science instruments on board the LCROSS spacecraft captured the entire crash sequence of the Centaur impactor before the spacecraft itself impacted the surface of the moon. But from Earth, any evidence of the plume was hidden by the rim of a giant impact basin, a 3 kilometer-high (2-mile) mountain directly in the way for Earth telescopes trained on the impact site, said Dr. Peter Schultz, co-investigator for LCROSS. Additionally, the crater created by the impact was only about 28 meters across (92 feet) but Schultz said the best resolution Earth telescopes can garner is about 180 meters (200 yards) across.
The science team is analyzing the data returned by LCROSS, and Anthony Colaprete, principal investigator and project scientist, said “We are blown away by the data returned. The team is working hard on the analysis and the data appear to be of very high quality.”
The team hopes to release some of their preliminary findings within the next several weeks, Schultz said at in webcast with students and teachers this week.
During the Oct. 9 crash in to the Moon’s Cabeus crater, the nine LCROSS instruments successfully captured each phase of the impact sequence: the impact flash, the ejecta plume, and the creation of the Centaur crater.
Within the ultraviolet/visible and near infra-red spectrometer and camera data was a faint, but distinct, debris plume created by the Centaur’s impact.
“There is a clear indication of a plume of vapor and fine debris,” said Colaprete. “Within the range of model predictions we made, the ejecta brightness appears to be at the low end of our predictions and this may be a clue to the properties of the material the Centaur impacted.”
The magnitude, form, and visibility of the debris plume add additional information about the concentrations and state of the material at the impact site.
From images and data, the team was able to determine the extent of the plume at 15 seconds after impact was approximately 6-8 km in diameter. Schultz said the Moon’s gravity pulled down most of ejecta within several minutes.
The LCROSS spacecraft also captured the Centaur impact flash in both mid-infrared (MIR) thermal cameras over a couple of seconds. The temperature of the flash provides valuable information about the composition of the material at the impact site. LCROSS also captured emissions and absorption spectra across the flash using an ultraviolet/visible spectrometer. Different materials release or absorb energy at specific wavelengths that are measurable by the spectrometers. the locations of the Diviner LCROSS impact swaths overlain on a grayscale daytime thermal map of the Moon’s south polar region. Diviner data were used to help select the final LCROSS impact site inside Cabeus Crater, which sampled an extremely cold region in permanent shadow that can serve as an effective cold trap for water ice and other frozen volatiles. Credit NASA/GSFC/UCLA
Additionally, the Lunar Reconnaissance Orbiter’s Diviner instrument also obtained infrared observations of the LCROSS impact. LRO flew by the LCROSS Centaur impact site 90 seconds after impact at a distance of ~80 km. Both science teams are working together to analyze the their data.
The LCROSS spacecraft captured and returned data until virtually the last second before impact, Colaprete said, and the thermal and near-infrared cameras returned excellent images of the Centaur impact crater at a resolution of less than 6.5 feet (2 m).
“The images of the floor of Cabeus are exciting,” said Colaprete. “Being able to image the Centaur crater helps us reconstruct the impact process, which in turn helps us understand the observations of the flash and ejecta plume.”
Chandrayaan-1 SARA measurements of hydrogen flux recorded on the Moon on 6 February 2009. Credits: Elsevier 2009 (Wieser et al.), ESA-ISRO SARA data
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In late September, a team of scientists announced finding water molecule signatures across much of the Moon’s surface. Now, a second instrument on board India’s Chandrayaan-1’s lunar orbiter confirms how the water is being produced. The Sub keV Atom reflecting Analyzer (SARA) corroborates that electrically charged particles from the Sun interact with the oxygen present in some dust grains on the lunar surface to produce water. But the results bring out a new mystery of why some protons get reflected and not absorbed.
Scientists likened the Moon’s surface to a big sponge that absorbs the electrically charged particles. The lunar surface is a loose collection of irregular dust grains, or regolith, and the incoming charged particles should be trapped in the spaces between the grains and absorbed. When this happens to protons they are expected to interact with the oxygen in the lunar regolith to produce hydroxyl and water.
The SARA results confirm findings from Chandrayaan-1’s Moon Mineralogy Mapper (M3) that solar hydrogen nuclei are indeed being absorbed by the lunar regolith; however SARA data show that not every proton is absorbed. One out of every five rebounds into space. In the process, the proton joins with an electron to become an atom of hydrogen.
“We didn’t expect to see this at all,” says Stas Barabash, Swedish Institute of Space Physics, who is the European Principal Investigator for SARA. The Sub Kev Atom reflecting Analyser (SARA)on board the lunar mission Chandrayaan-1. SARA is the first-ever lunar experiment dedicated to direct studies of plasma-surface interactions in space. Credits: ISRO/ESA/Swedish Institute Of Space Physics
Although Barabash and his colleagues do not know what is causing the reflections, the discovery paves the way for a new type of image to be made. Unfortunately, since the Chandrayaan-1 orbiter is no longer functioning, new data can’t be taken. However, the team can work with data already collected to further study the process.
The hydrogen shoots off with speeds of around 200 km/s and escapes without being deflected by the Moon’s weak gravity. Hydrogen is also electrically neutral, and is not diverted by the magnetic fields in space. So the atoms fly in straight lines, just like photons of light. In principle, each atom can be traced back to its origin and an image of the surface can be made. The areas that emit most hydrogen will show up the brightest.
While the Moon does not generate a global magnetic field, some lunar rocks are magnetized. Barabash and his team are currently creating images from collected data, to look for such ‘magnetic anomalies’ in lunar rocks. These generate magnetic bubbles that deflect incoming protons away into surrounding regions making magnetic rocks appear dark in a hydrogen image.
The incoming protons are part of the solar wind, a constant stream of particles given off by the Sun. They collide with every celestial object in the Solar System but are usually stopped by the body’s atmosphere. On bodies without such a natural shield, for example asteroids or the planet Mercury, the solar wind reaches the ground. The SARA team expects that these objects too will reflect many of the incoming protons back into space as hydrogen atoms.
Scientists with the ESA’s BepiColombo mission to Mercury are hoping to study the interaction between charged particles and the surface of Mercury. The spacecraft will be carrying two similar instruments to SARA and may find that the inner-most planet is reflecting more hydrogen than the Moon because the solar wind is more concentrated closer to the Sun.
The Near Infrared camera on LCROSS captured this image of the lunar south pole on its way into impact on October 9, 2009. It watched the Centaur upper stage crash into a permanently shadowed area of the crater Cabeus.Credit: NASA / ARC
Even without big explosions or bright plumes of ejecta, for all intents and purposes it appears LCROSS’s impact on the Moon was a smashing success. While the mainstream media and the public seemed disappointed in the lack of visual data, mission managers said the mission has garnered plenty of spectroscopic data, and that’s where the real science can be found. “There was an impact and we saw the crater with spectroscopic data,” said LCROSS principal investigator Tony Colaprete. “We have the data we need to address the questions we set out to answer.” The big question is whether the impact kicked up any signatures of water ice, but it could take days, weeks or months to analyze all the data.
Initial video and images from the event – taken by LCROSS itself and a wide variety of space- and ground-based telescopes – did not show much as far as a visible impact or the anticipated ejecta plume.
Was that a surprise to the science team? “I guess I’m not necessarily surprised,” said Colaprete. “Impacting the Moon is tricky business, and you learn to expect what you’re not going to expect. I’m not convinced we haven’t seen the ejecta. I want to go back to images and look at them carefully. We’ve had just 15-20 minutes of our efforts so far with images. So stay tuned. I certainly hope we can dig something out that will be telling. Our emphasis was on the spectra, that’s where the information is.” Mid Infrared Camera flash detection of Centaur impact. Credit: NASA
Just two and a half hours after impact, mission managers spent most of Friday morning’s press conference explaining how little chance they had to look at the data – and that they wouldn’t even approach the topic of whether water had been detected yet — and how the impact doesn’t end the mission. “This is just the beginning,” said Michael Wargo, NASA’s chief lunar scientist. “We’ve got an enormous amount of data, not only from LCROSS from assets around the world. This is going to change the way we look at the Moon scientifically and change the way we do future exploration.”
High praise was given to the operations and observation campaign teams, as well as the spacecraft itself. “I’m happy to report spacecraft performed beautifully and the operations team did very well,” said Dan Andrews, LCROSS Project Manager. “It takes awhile to comb through the data to make sure we are reporting accurate and correct data, but we wanted to give you all an update on how things went.”
Here’s what they know so far:
They saw a flash at impact with the near infrared camera on LCROSS, and were able to see that an impact occurred, and even see the crater itself. “We had a very good high signal to noise data on the LCROSS spectrometer, probably the highest we could hope for,” said Colaprete. “The fact that we saw a remnant crater and that we got data as far down as we did, it’s very promising. Just on my initial eyeballing, the crater looked to be about the size we were predicting; about 18-20 feet or more. It filled a whole pixel of the camera.” A closer view of the moon as the LCROSS spacecraft approaches impact. Credit: NASA
“The cameras worked very well and we were able to track the Centaur all the way to the end of the mission” Colaprete continued, and then addressed a possible reason why the ejecta plume wasn’t more visible. “There was a flicker from the Centaur that might have been from a tumbling action. We wanted to avoid a perfectly end-on or perfectly flat impact, and it’s possible that happened. But we have the information we can go back now and look at everything.” This image was taken by the Palomar Observatory at the time of impact. Credit: Palomar Observatory
Data from several other spacecraft and telescopes were just starting to trickle in, as well.
On the Lunar Reconnaissance Orbiter, which was observing the impact event from lunar orbit, the LAMP instrument (UV spectrometer) and the Diviner instrument (imaging radiometer) confirmed detection of the ejecta plume. The LRO teams have begun analyzing their data.
The Hubble Space Telescope also observed the event, but not in visible light. “HST was highly focused on spectroscopy, which is where the science is,” Colaprete said. “HST cannot look at the moon except for the very narrow filters because it is so bright. It took long integration stares just off to the side of the Moon.”
Other assets observing the event included IKONOS, GeoEye 1, ODIN — a Swedish radio telescope – all in Earth orbit, and Keck Observatory on Mauna Kea, the Palomar Observatory and MMTO.
Jennifer Heldmann who led the LCROSS observation campaign described some of the data obtained by a all the different telescopes and spacecraft: “We have images, we have video, we have graphs with squiggly lines, which scientists love.”
One surprise is that in the initial data, sodium was seen in the spectroscopic data, and Colaprete said sodium exists in the Moon’s tenuous atmosphere called the exosphere, and perhaps something got thermalized during the impact excite the sodium atoms to where strong visible emission lines showed up in the data.
Other “blips” in the data showed up, and while Colaprete said he couldn’t say what they meant, he was just glad there were there.
“As of now, this has just been a real-time mission,” he said. “We laid it all out there by having streaming video, but here we are at 2 hours. Our primary objective was finding out about the hydrogen that’s been observed at the lunar poles, and honestly, our initial visual images didn’t answer that question. But the answers are in the spectra and we’ve got something there. It could be days, weeks, or months until we can give you an answer. We’ll look at data, scratch our heads, fight over who gets to look at which data, and hopefully from that we can make a public announcement of what we’ve found.”
LCROSS Close Up Side view of LCROSS wrapped in gold colored multi layer thermal insulation. Note solar array at left. Science instrument, avionics, navigation, communication and thruster equipment panels encircle and are attached to the central payload adapter ring. Star tracker at right. Payload fairing halves sit at either side. Credit: Ken Kremer and the Planetary Society. Used by permission.
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The LCROSS spacecraft will be giving it all up for science Friday morning when it and the second stage of the Centaur rocket impact Cabeus crater on the Moon’s south pole, searching for possible water ice hidden inside the perpetually dark portions of the crater. Since we’ll never see LCROSS again, its only fitting to take a good long, last look at her. Solar System Ambassador and Planetary Society volunteer Ken Kremer had the wonderful opportunity to see both LCROSS and her sister ship the Lunar Reconnaissance Orbiter (LRO) in the Astrotech Space Operations Facility clean room in Titusville, FL earlier this year before the dynamic duo launched together on June 18. Ken has graciously given permission to allow us to publish these images (which were previously posted on the Planetary Society website) so we can all remember what she looked like. Above is a side view of LCROSS wrapped in gold multi-layer thermal insulation. The solar array is on the left side. Science instrument, avionics, navigation, communication and thruster equipment panels encircle and are attached to the central payload adapter ring. The star tracker is on the right side, and the payload fairing halves sit at either side.
More images below.
LRO, LCROSS and Ken Kremer. Credit: Ken Kremer and the Planetary Society.
Here’s a picture of Ken with the two spacecraft. Visible are the solar arrays for LRO (top, left) and LCROSS (bottom, left). Visible is the LCROSS panel with the 9 science instruments (gold color) which run on just 100 watts of power. Above Ken’s head is the visible light camera.
LRO (gray) and LCROSS (yellow) lunar spacecraft stacked adjacent to Atlas V payload fairing at Astrotech Payload Facility on May 15, 2009. Credit: Ken Kremer and the Planetary Society.
This image really provides a reference to how big these two spacecraft actually are. Note the person in the bunny (clean) suit standing next to LRO (gray) and LCROSS (yellow) lunar spacecraft stacked adjacent to Atlas V payload fairing.
And since we’ve now seen LCROSS up close, here’s a few new close-up images just released by NASA of Cabeus crater. A birds-eye view of Cabeus crater, LCROSS' target. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio
This visualization image gives a bird’s-eye view of Cabeus crater and the target zone for the crash site. A 3.5-kilometer-wide “flagpole” marks the targeted location within the crater. Colored stripes on the pole indicate one kilometer steps in elevation above the crater floor, black stripes indicate 5 kilometer steps. The pole stands 25 kilometers tall, and the blue rings mark heights of 50 and 100 kilometers above the impact site. Key landmarks to locate Cabeus Crater. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio
This image shows key lunar landmarks used to locate Cabeus crater. The yellow scale shows angular distances in the plane of the impact site; blue arcs show heights 50, 100 and 200 kilometers above it.
And click here for a link to a video visualization that zooms into Zoom into the Moon as it might look shortly after the LCROSS impact. Blue arcs represent 50, 100 and 200 kilometer heights above the crash site.
Hopefully the telescopes trained on this region of the Moon will give us the real images of this event!
Lead image caption: LCROSS Close Up. Side view of LCROSS wrapped in gold colored multi layer thermal insulation. Note solar array at left. Science instrument, avionics, navigation, communication and thruster equipment panels encircle and are attached to the central payload adapter ring. Star tracker at right. Payload fairing halves sit at either side.
Credit: Ken Kremer
Artist concept of the Centaur and LCROSS heading towards the Moon. Credit: NASA
There seems to be a little lunacy making the rounds that NASA is going to “bomb” the Moon on Friday morning, or “hurt the Moon,” or “split the Moon in half,” or change its orbit. This is all just nonsense and scare-mongering, and those worried about our Moon can rest assured our lunar companion will remain in the sky relatively unchanged after this experiment to search for water ice on the Moon’s south pole. Let’s take a look at the physics involved and what might happen to the Moon.
First of all, there are no explosives involved. The LCROSS mission is going sending a upper stage of a Centaur rocket and a smaller spacecraft to impact the Moon. The two objects will create a crater — The 5,000-pound (2,270-kilogram) Centaur is expected to slam into Cabeus Crater on the Moon’s south pole at a sharp angle at a speed of 5,600 mph (9,000 kilometers per hour). The Centaur’s collision is expected to create a crater roughly 60 or 70 feet wide (20 meters wide) and perhaps as much as 16 feet (5 meters) deep, ejecting approximately 385 tons of lunar dust and soil — and hopefully some ice.
The LCROSS spacecraft itself, weighing in at 1,500-pounds (700-kilograms), will follow the Centaur by about four minutes and fly through the regolith plume thrown up by the collision, just before it too slams into the lunar surface, kicking up its own smaller plume of debris, all the while using its sensors to look for telltale signs of water, beaming the information back to Earth.
So, yes, it will make a rather big crater on the Moon. But one close-up look at the lunar surface will reveal that the Moon is full of craters, and still regularly receives hits by meteorites and larger space rocks – not as much as in the past, as most of the craters on the Moon are from an earlier period in our history when there was more debris left over from the formation of the solar system. The Moon was not “hurt” in the past, and it will not get hurt by this impact. Additionally, other spacecraft have hit the lunar surface with no adverse effects on the Moon or its orbit.
The Atlas V Centaur upper stage has a mass of 2,000 kg (the more massive of the two vehicles impacting the Moon). It will be moving at 5,600 mph (2.5 km/sec.) BAM! By comparison, the Moon is orbiting the Earth at the measely speed of 2,300 mph (1.022 km/sec). On the other hand, the Moon is just a tad bit more massive than the specks on a collision course.
So let’s say we wanted to change the Moon’s speed by JUST 1 MPH (0.0004 km/sec)—which is less than 1/2,000th its orbital speed—and we were going to do it by hurling Atlas V Centaur upper stages at the Moon. How many would we have to hurl its way? HEY, let’s give every person on planet Earth an opportunity to hurl one. Would that do it? Uh … nope. Every person on Earth (all nearly 7 billion of us) would each need to hurl 1 MILLION Atlas V Centaur upper stages at the Moon. I’d rather just hurl one and not worry about it. Rest easy, sleep well, and let’s see if we can find water on the Moon at the South Pole.
Another question people have been asking: Will the impact destroy the water we are looking for?
NASA answers that question on the LCROSS FAQ site:
The LCROSS impact will have the same effect on the water (if it is indeed there) as any other object that might naturally impact it. Most (>90%) of any water that is excavated by LCROSS will most likely return to nearby “cold traps”. The LCROSS impact is actually a slow impact and, thus, most of the material is not thrown very high upward, rather outward, adjacent to the impact site. Of the water that does get thrown upward, much of it will actually return to the Moon and eventually find its way back to the dark, cold craters. This is actually one possible way that the water was supplied in the first place: it was deposited following the impacts of comets and asteroids.
There is about 12,500 square km of permanently shadowed terrain on the Moon. If the top 1 meter of this area were to hold 1% (by mass) water, that would be equivalent to about 4.1 x 1011 liters of water! This is approximately 2% the volume of the Great Salt Lake in Utah. The LCROSS impact will excavate a crater approximately 20 meters in diameter, or about one-trillionth the total permanently shadowed area. It is safe to say the LCROSS impact will not have a lasting effect on lunar water, if it does indeed exist.
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The LCROSS spacecraft is going to impact the Moon on Friday, October 9, and here’s your chance to watch the action, either just for fun, or to contribute to scientific observations. Whether you want to observe with your own equipment or watch the event on television or a webcast, below you’ll find all the information and links you should need to be a part of history. Amateur astronomers need a 10-inch or bigger telescope to make observations.
When: Following the latest trajectory correction maneuvers, the time of impact on Friday, October 9, 2009 is 11:31:19 UTC for the Centaur and 11:35:45 for LCROSS spacecraft (7:31:19 a.m. EDT and 7:35:45 a.m. EDT).
The impact time may be refined as the time for impact comes closer. You can check the LCROSS mission Facebook and Twitter pages for the latest updates (and we’ll try to post it here as soon as possible after any changes are announced.) Also check this NASA website for more information.
New Mexico State University and Marshal Space Flight Center have made finder charts available based on similar illumination and libration that we expect to see on the night of the impact.
In general, here’s where to look: Start with the south pole (bottom edge) and look for the terminator, or where the sunlight and shadow merge. Here’s what the Moon should look like:
Zoom in with your telescope and identify the Cabeus craters. The target is in Cabeus proper, near the bottom of the Moon. Here’s what it should look like, along with a notated image: Craters on the Moon's south pole.
What will I see? Based on an projections, there should be a visible ejecta cloud rising to 6Km above the lunar surface and crater wall. Latest estimates of the Cabeus proper crater impact site indicate the first two or three kilometers of that plume height (the brightest parts) may not be viewable from Earth, but that the plume will hopefully have crater wall shadow behind it to help us see it. Impact design location is to maximize the amount of this in sunlight, but variables here will determine how much of it is actually illuminated, and it may be that only the high power instruments will see good contrast. But we don’t know for sure.
“We expect the debris plumes to be visible through mid-sized backyard telescopes—10 inches and larger,” says Brian Day of NASA/Ames. Day is an amateur astronomer and the Education and Public Outreach Lead for LCROSS. “The initial explosions will probably be hidden behind crater walls, but the plumes will rise high enough above the crater’s rim to be seen from Earth.”
What is actually going on? The 5,000-pound (2,270-kilogram) Centaur is expected to slam into Cabeus at a sharp angle at a speed of 5,600 mph (9,000 kilometers per hour). If all goes according to schedule, the shepherding vehicle, carrying nine science payloads, will follow the Centaur’s plunge into the moon, and send back data live to Earth. The Centaur’s collision is expected to create a crater roughly 60 or 70 feet wide (20 meters wide) and perhaps as much as 16 feet (5 meters) deep, ejecting approximately 385 tons of lunar dust and soil — and hopefully some ice. In addition to recording the collision, the shepherding spacecraft weighing, 1,500-pounds (700-kilograms) will fly through the regolith plume thrown up by the collision, just before it too slams into the lunar surface some four minutes later, kicking up its own smaller plume of debris, all the while using its sensors to look for telltale signs of water.
What if it is cloudy where I live, or I live in Europe/Asia and it is daytime, or I don’t have a telescope to watch?
Also, if you are in Mumbai, India the Nehru Planetarium there has a free viewing of the event at 4 pm IST. (thanks for pradx on Twitter for that info.)
If you are in the Pasadena area, JPL’s Von Karman Auditorium will have a public viewing, opening the gates 3:00 am. local time.
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Since the LCROSS team reloaded and switched which lunar crater they are targeting for impact with the spacecraft and its upper stage of the Centaur rocket on October 9, the SMART-1 team has reloaded as well, and has released an updated image of the new crater. LCROSS (Lunar Crater Observation and Sensing Satellite) will search for water ice on the Moon by making two impacts into Cabeus crater at the lunar South Pole. The impacts are scheduled for 11:31:19 UTC and 11:35:45 UTC.
Previously, the SMART-1 team had released an image of Cabeus A, the original target crater.
Bjoern Grieger, the liaison scientist for SMART-1’s AMIE camera, and Bernard Foing, ESA SMART-1 Project Scientist, searched through SMART-1’s database for images of Cabeus, taken four years ago. The
SMART-1 images are at high resolution as the spacecraft was near its closest distance of 500 km from the South Pole.
The Cabeus crater interior is permanently shadowed, so ice lying inside the crater could be protected from the Sun’s harsh rays. LCROSS will send the upper stage Centaur rocket crashing into Cabeus and a
shepherd spacecraft will fly into the plume of dust generated and measure its properties before making a second impact with the lunar surface. Astronomers will observe both impacts using ground and space-based telescopes. The SMART-1 spacecraft also concluded its mission with a controlled bouncing impact on September 3, 2006. The event was observed with ground-based telescopes (a “dry run” for LCROSS), and the flash from the impact was detected at infrared wavelengths.
“The Cabeus topographic features as observed by SMART-1 vary greatly during the lunar rotation and the yearly seasons due to the polar grazing illumination conditions,” said Foing. “The floor of Cabeus
near LCROSS targets shows a number of small craters and seems old enough to have accumulated water ice delivered from comets and water-rich asteroids, and might have kept it frozen in its shadowed
area.”
NASA’s Marshall Space Flight Center is testing a new robotic lunar lander test bed that will aid in the development of a new generation of multi-use landers for future robotic space exploration. Image Credit: NASA/MSFC/David Higginbotham
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The best way to study the new-found water on the Moon would be with in-situ instruments. Since humans won’t be making any lunar landings for at least a decade, the next best option is robotic spacecraft. NASA’s Marshall Space Flight Center is developing and testing a new robotic lander to explore not only the Moon, but also asteroids and Mars. This design is definitely next generation: it’s bigger than any lander yet and MSFC is currently testing the all-important final of reaching the destination: landing.
“Specifically, what we are doing at Marshall is identifying the terminal – or the final – phase of landing, and designing a robotic lander to meet those needs,” said Brian Mulac, a test engineer at Marshall, quoted in an article in the Huntsville Times. “That last part is the highest risk of setting down on the moon.”
Of course, parachutes can’t be used for landing on the Moon or asteroids, since neither destination has an atmosphere, so thrusters are key for landing.
Large, oval-shaped tanks on the craft are used to store fuel for thrusters. Thrusters guide the lander, controlling the vehicle’s altitude and speed for landing. An additional thruster on this test vehicle, above, offsets the effect of Earth’s gravity so that the other thrusters can operate as they would in a lunar environment.
Just in case the tests don’t go as planned, a huge net is place under the lander to catch the vehicle and avoid damaging it.
As the saying goes, it’s not the fall that’s dangerous, but the sudden stop.
