For almost half a century, the term “Anthropocene” has been informally used to describe the current geological epoch. The term acknowledges how human agency has become the most significant factor when it comes to changes in Earth’s geology, landscape, ecosystems, and climate. According to a new study by a team of geologists and anthropologists, this same term should be extended to the Moon in recognition of humanity’s exploration (starting in the mid-20th century) and the growing impact our activities will have on the Moon’s geology and the landscape in the near future.
Caption: LROC image showing the illuminated side of the still standing American flag to be captured at the Apollo 17 landing site. Credit: NASA/GSFC/Arizona State University.
Mark Robinson, Principal Investigator of the Lunar Reconnaisance Orbiter Camera (LROC) says the most often-asked questions he gets about the images LRO has taken of the Moon are about pictures of the Apollo landing sites and what is visible. Especially, Robinson said, people want to know if the flags are still standing.
Previously, Robinson has said that while the flag poles are likely still standing, he didn’t think the flags themselves survived the harsh radiation of the lunar surface environment. But new images and video show that at some of the landing sites – Apollo 12, Apollo 16, and Apollo 17 – the flags must still be intact, because they are creating shadows on the surface.
“Personally I was a bit surprised that the flags survived the harsh ultraviolet light and temperatures of the lunar surface, but they did,” Robinson wrote on the LROC website. “What they look like is another question (badly faded?).”
Caption: The flag was captured in this image of the Apollo 16 site with the spacecraft slewed 15° towards the Sun; the shadowed side of the flag is seen by LROC. Credit: NASA/GSFC/Arizona State University.
James Fincannon, a NASA engineer from Glenn Research Center, combined LROC images of each Apollo site taken at roughly the same orientation but with different Sun angles to show the travel of shadows.
“Combined with knowledge of the Apollo site maps which show where the flag was erected relative to the Lander, long shadows cast by the flags at the three sites show that the these flags are still “flying”, held aloft by the poles,” Fincannon wrote.
And so, from the LROC images it is now certain that the American flags are still standing and casting shadows at all of the sites, except Apollo 11. Astronaut Buzz Aldrin reported that the flag was blown over by the exhaust from the ascent engine during liftoff of Apollo 11, and Robinson said that from the images of the Apollo 11 landing site, it looks like he was correct.
Caption: Enlargement of area surrounding Apollo 11 landing site. Credit: NASA/GSFC/Arizona State University
Robinson added that the most convincing way to see that the flags are still there, is to view a time series of LROC images taken at different times of day, and watch the shadow circle the flag (see movie below; the flag is just above the LM descent stage).
Low periapsis Narrow Angle Camera image of the Apollo 17 Landing Site. Image is 150 meters wide, Credit: NASA/GSFC/Arizona State University.
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New images of the Apollo 12, 14 and 17 landing sites are the highest resolution pictures ever of human forays onto another world, as seen from a bird’s eye view — or in this case, a satellite’s eye view. The Lunar Reconnaissance Orbiter dipped to a lower altitude, just 21 kilometers (13 miles) over the lunar surface.
“We like to look at the Apollo landing site images because it’s fun,” said LRO principal investigator Mark Robinson at a media briefing today. “But LROC (Lunar Reconnaissance Orbiter Camera) is looking at the whole Moon, and we have now taken 1,500 of these very high resolution images from all around the Moon which will help scientists and engineers to plan where we want to go in the future.”
Apollo 17 landing site taken by LRO in its lower orbit, with 25 cm per pixel. Credit: NASA/Goddard/ASU
Apollo 17 landing site from the regular 50 km altitude and about 50 cm per pixel. Credit: NASA/ Goddard/ ASU Compare in the images above the Apollo 17 landing site with 25 cm per pixel (top) and 50 cm per pixel (bottom).
Most notable are the tracks where the astronauts walked show up better, and details of the landers/descent stages can be resolved better.
Robinson said he was looking at the new images of the Apollo 17 landing site in Taurus Littrow Valley with Apollo 17 astronaut Jack Schmitt and Schmitt said “You need to image the whole valley at this resolution!”
This is the third resolution of Apollo sites that the LRO team has released — the first came from LRO’s commissioning phase where the altitude was about 100 km and the resolution was about 1 meter per pixel; next came the release of images from an altitude of about 50 km, with a resolution of about 50 cm per pixel; and now from about 21-22 km altitude with a resolution of 25 cm per pixel.
“These are the sharpest images of Apollo landing sites we’ll probably ever get with LRO,” said Rich Vondrak, LRO project scientist, “as we’ll never go as low in altitude as we were in the past month.”
LRO has now returned to its circular orbit of 50 km above the surface. This altitude requires monthly reboosts and since keeping LRO in that orbit would quickly exhaust the remaining fuel, in mid-December, LRO will move to an elliptical orbit, (30 km over south pole and 200 km over north pole). LRO will be able to stay in this orbit for several more years.
“This has been a highly productive mission, releasing a total of 245 terabytes of data — which would be a stack of 52,000 DVDs,” Vondrak said. Next week the science team will put out their 7th public release of data to the Planetary Data System, making all that data available to the public.
The paths left by astronauts Alan Shepard and Edgar Mitchell on both Apollo 14 moon walks are visible in this image. (At the end of the second moon walk, Shepard famously hit two golf balls.) The descent stage of the lunar module Antares is also visible. Credit: NASA's Goddard Space Flight Center/ASU
Robinson noted that the details of what pieces of equipment are in each location are verified by images taken from the surface by the astronauts. He was asked about the flags and if they are still standing: “All we can really see is the spots where the flag was planted because the astronauts tramped down the regolith. I’m not sure if the flags still exist, given the extreme heat and cold cycle and the harsh UV environment. The flags were made of nylon, and personally I would be surprised if anything was left of them since it has been over 40 years since they were left on the Moon and the flags we have here on Earth fade after they are left outside for one summer. If the flags are still there they are probably in pretty rough shape.”
The tracks made in 1969 by astronauts Pete Conrad and Alan Bean, the third and fourth humans to walk on the moon, can be seen in this LRO image of the Apollo 12 site. The location of the descent stage for Apollo 12's lunar module, Intrepid, also can be seen. Credit: NASA/Goddard/ASU
Since we can still see the tracks and equipment looking unchanged (at least from this vantage point) one reporter asked if these items will be on the Moon forever. “Forever is a long time, so no, they won’t be there forever,” Robinson replied. “The Moon is constantly bombarded by micrometeorites, and slowly over time the tracks will disappear, then the smaller pieces of equipment will disappear, and eventually the decent stages will probably get blasted by an a larger asteroid. The estimate is that rocks erode 1 mm per million years. In human terms it may seems like forever, but geologic terms, there will be no traces of Apollo exploration in 10 to 100 million years.”
This video shows more info and a “zoom in” of the sites:
Apollo 11 landing site. Credit: NASA/GSFC/Arizona State University, 3-D by Nathanial Burton-Bradford.
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With the Lunar Reconnaissance Orbiter Camera constantly snapping images of the lunar surface, we have been able to see most of the Apollo landing sites with better and better detail. Image editing wizard Nathanial Burton-Bradford has now “3-D-ified” all the landing sites except Apollo 16, and by viewing these images with 3-D glasses (the ones with red and cyan lenses) the lunar landers are easily visible and really stand out. Other features such as tracks and experiments left by the Apollo astronauts become more visible as well. See more images below, and click on the images for larger versions, or see Nathanial’s Flickr page for more!
The Apollo 12 landing site. Credit: NASA/GSFC/Arizona State University, 3-D by Nathanian Burton-Bradford
Apollo 14 landing site. Credit: NASA/GSFC/Arizona State University, 3-D by Nathanial Burton-Bradford.
Apollo 15 landing site. Credit: NASA/GSFC/Arizona State University, 3-D by Nathanial Burton-Bradford.
Apollo 17 landing site. Credit: NASA/GSFC/Arizona State University, 3-D by Nathanial Burton-Bradford
And for good measure, here’s one of the impact crater created by the Apollo 17 Saturn booster.
The crater made by the Apollo 17 booster. Credit: NASA/GSFC/Arizona State University, 3-D by Nathanial Burton-Bradford.
Apollo 14 landing site in 3-D. Image: LRO, Anaglyph by Nathanial Burton-Bradford. Click for larger version.
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Time to grab your 3-D glasses! Just got a note from Nathanial Burton-Bradford, one of the image editing wizards we have featured here at Universe Today. His latest handiwork is creating some 3-D analglyphs of images from the Lunar Reconnaissance Orbiter, and particularly of the Apollo landing sites. As Nathanial wrote me, “In a word, WOW!” Nathanial’s images make the lunar landers really stand out and stand *up* in the images, and other features such as tracks and experiments left by the Apollo astronauts become more visible as well. See more images below, and click on the images for larger versions, or see Nathanial’s flickr page for lots more!
Apollo 15 landing site in 3-D. Image by LRO, Analglyph by Nathanial Burton Bradford. Click for larger version.
Apollo 11 landing site in 3-D. Image: LRO, Anaglyph by Nathanial Burton-Bradford. Click for larger version.
You’ve seen the pictures, now watch the movie! Zoom into the Apollo 11 landing site with the Lunar Reconnaissance Orbiter’s latest images of Tranquility Base where humans took their first steps on the Moon. Thrill with the detail! Swoon with the history! Or, just enjoy it.
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.
