Apollo 14 booster impact site on the Moon. Credit: NASA/Goddard Space Flight Center/Arizona State University
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Speaking of lunar impacts: While we await the science data from the LCROSS mission impact earlier this morning, the Lunar Reconnaissance Orbiter team has released this image of another impact on the Moon 38 years ago . The crater in the center of this image was formed by Apollo 14’s Saturn IVB booster. The booster was intentionally impacted into the lunar surface on Feb. 4, 1971. The impact caused a minor “moonquake” that scientists used to learn about the moon’s interior structure. Seismometers placed on the surface by the Apollo 12 astronauts returned data on the tremor.
The crater is about 35 meters (115 feet). The interior of the crater has bright mounds, and a bright ejecta blanket surrounds the exterior of the crater. Bright rays are observed to extend across the surface for more than 1.5 km (0.9 miles) from the impact. This LROC image was taken when the sun was relatively high in the sky, bringing out subtle differences in reflectivity or brightness. This site has been observed before, and scientists noted the unusual occurrence of dark and bright rays when the Apollo 16 spacecraft observed the site.
Comparing the Apollo booster impact to LCROSS, the Apollo impact velocity was at 9,144 kph (5,682 mph.) The booster component weighed 14,000 kg (30,835 lbs) at the time of impact, and the impact energy was equivalent to just over 10 tons of TNT. A seismometer placed in 1969 by Apollo 12 astronauts recorded the vibrations, which lasted for about three hours. The LCROSS impactor (the upper stage of a Centaur rocket) is much smaller than the S-IVB and thus will make a smaller crater. The Centaur weighs about 2000 kg (4,409 lbs) and will hit with a velocity of about 9,000 kph (5,592 mph.)
So anyone worried about the LCROSS impact; don’t worry, the Moon has seen much worse from earlier impacts — both intentional by humans and the unintentional consequences of being in a space-dust and -debris filled region of space.
UPDATE: The MMTO Telescope on Mount Hopkins in Arizona has video from their observations that, while fuzzy, possibly show a bright plume emerging from the crater. (Further analysis says probably not). The video is here,,
In a bit of an anti-climax, the Centaur second stage, and later the LCROSS spacecraft impacted Cabeus Crater but produced no visible plume. Analysis of navigation telemetry indicated the trajectory was spot on, and the Centaur should have hit the surface to within about 64 meters (210 feet) of the planned target. The video above is from NASA TV, and below if video from the Lick Observatory, whose 36-inch telescope was trained on the Moon’s south pole. They didn’t see anything, as reports from telescopes at Palomar, Arizona, and Mauna Kea also confirmed. But a dim impact would mean regolith ejecta, which scientists say is good because that means it hit more dirt than rocks. Another thing to remember is that science is not always “seen” in visible light. The LCROSS sensors and instruments will provide the best data.
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
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For the first time, astronomers have confirmed that an asteroid contains frozen water on its surface. Analysis of asteroid 24 Themis shows evidence of water ice along with organic compounds widespread across the surface. The scientists say these new findings support the theory that asteroids brought both water and organic compounds to the early Earth, helping lay the foundation for life on the planet.
Humberto Campins of the University of Central Florida in Orlando and colleagues recorded spectra of 24 Themis over a seven-hour period, and were able to study 84 percent of the rotational period of the spinning rock, Rob Cowen reported in Science News. Using NASA’s Infrared Telescope Facility on Hawaii’s Mauna Kea, the spectra revealed the consistent presence of frozen water as different parts of the asteroid’s surface came into view.
Analyses of the sunlight reflected off the asteroid also show that organic compounds are widespread on the surface, he added, including polycyclic aromatic hydrocarbons, CH2 and CH3.
The new finding corroborates earlier observations of the same asteroid by astronomers Andrew S. Rivkin and Joshua Emery who also used the Infrared Telescope Facility. Over several years, Rivkin and Emery had found evidence of frozen water in single spots on 24 Themis but had not studied the asteroid as it made one entire rotation. Together, the two teams’ findings reveal that the asteroid’s entire surface is coated with frozen water, Campins says.
The 160-kilometer wide asteroid averages a distance from the sun of about 3.2 times that of Earth’s. At that range, frozen water on the surface would readily vaporize, Campins said. That means the ice must be continually replenished, possibly by a reservoir of frozen water within the rock.
One possibility is that ice lies buried several meters below the surface of 24 Themis, and when hit by space debris, the ice makes its way to the surface. If this is the case, it could confirm that some asteroids resemble comets, becoming active suddenly and venting material into space when pockets of ice vaporize, Campins said.
Another option is that an action similar to the recent findings of water on the Moon, where solar wind interacts with a rocky body without an atmosphere to create H2O and OH molecules. Without an atmosphere, the body is exposed to solar wind, which includes hydrogen ions. The hydrogen is able to interact with oxygen in surface of the asteroid to create water molecules.
Campins shared his findings at the annual meeting of the American Astronomical Society’s Division for Planetary Sciences.
Noctis Labyrinthus on Mars. Image Credit: NASA/JPL-Caltech/University of Arizona . Click for larger version.
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My description of this image: “Holy moly — what a gorgeous shot!” NASA’s description of this image: “Layers in the lower portion of two neighboring buttes within the Noctis Labyrinthus formation on Mars are visible in this image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.”
Absolutely beautiful. Click the image for access to larger versions. ‘Nuf said.
Europa. CThe cracked, icy surface of Europa. The smoothness of the surface has led many scientists to conclude that oceans exist beneath it. Credit: NASA/JPLredit: NASA
The global ocean on Jupiter’s moon Europa contains about twice the liquid water of all the Earth’s oceans combined. New research by Richard Greenberg of the University of Arizona suggests that there may be plenty of oxygen available in that ocean to support life, a hundred times more oxygen than previously estimated.
The chances for life there have been uncertain, because Europa’s ocean lies beneath several miles of ice, which separates it from the production of oxygen at the surface by energetic charged particles (similar to cosmic rays). Without oxygen, life could conceivably exist at hot springs in the ocean floor using exotic metabolic chemistries, based on sulfur or the production of methane. However, it is not certain whether the ocean floor actually would provide the conditions for such life.
Therefore a key question has been whether enough oxygen reaches the ocean to support the oxygen-based metabolic process that is most familiar to us. An answer comes from considering the young age of Europa’s surface. Its geology and the paucity of impact craters suggests that the top of the ice is continually reformed such that the current surface is only about 50 million years old, roughly 1% of the age of the solar system.
Greenberg has considered three generic resurfacing processes: gradually laying fresh material on the surface; opening cracks which fill with fresh ice from below; and disrupting patches of surface in place and replacing them with fresh material. Using estimates for the production of oxidizers at the surface, he finds that the delivery rate into the ocean is so fast that the oxygen concentration could exceed that of the Earth’s oceans in only a few million years.
Greenberg says that the concentrations of oxygen would be great enough to support not only microorganisms, but also “macrofauna”, that is, more complex animal-like organisms which have greater oxygen demands. The continual supply of oxygen could support roughly 3 billion kilograms of macrofauna, assuming similar oxygen demands to terrestrial fish.
The good news for the question of the origin of life is that there would be a delay of a couple of billion years before the first surface oxygen reached the ocean. Without that delay, the first pre-biotic chemistry and the first primitive organic structures would be disrupted by oxidation. Oxidation is a hazard unless organisms have evolved protection from its damaging effects. A similar delay in the production of oxygen on Earth was probably essential for allowing life to get started here.
Richard Greenberg is the author of the recent book “Unmasking Europa: The Search for Life on Jupiter’s Ocean Moon.” He presented his findings at the 41st meeting of the American Astronomical Society’s Division for Planetary Sciences.
I’m a day late (sorry!) but here’s this week’s image for the Where In The Universe Challenge, to test your visual knowledge of the cosmos. You know what to do: take a look at this image and see if you can determine where in the universe this image is from; give yourself extra points if you can name the spacecraft responsible for the image. We’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.
UPDATE: The answer has now been posted below.
This is an image of gravitational lens system SDSSJ0946+1006 as photographed by Hubble Space Telescope’s Advanced Camera for Surveys, and released in 2008.
The gravitational field of an elliptical galaxy warps the light of two galaxies exactly behind it. The massive foreground galaxy is almost perfectly aligned in the sky with two background galaxies at different distances. The foreground galaxy is 3 billion light-years away, the inner ring and outer ring are comprised of multiple images of two galaxies at a distance of 6 and approximately 11 billion light-years. The odds of seeing such a special alignment are estimated to be 1 in 10,000.
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.
