Animation of a temporal pair of the new 39-foot (12-meter) impact crater on the moon photographed by NASA’s Lunar Reconnaissance Orbiter Credit: NASA/GSFC/Arizona State University
We often hear how the Moon’s appearance hasn’t changed in millions or even billions of years. While micrometeorites, cosmic rays and the solar wind slowly grind down lunar rocks, the Moon lacks erosional processes such as water, wind and lurching tectonic plates that can get the job done in a hurry.
One of a series of photos Apollo 11 astronaut Edwin Aldrin made of his bootprint in the dusty, sandy lunar soil, called regolith. Based on a newy study, the impression may disappear in a few tens of thousands of years instead a few million. Credit: NASA
Remember Buzz Aldrin’s photo of his boot print in the lunar regolith? It was thought the impression would last up to 2 million years. Now it seems that estimate may have to be revised based on photos taken by the Lunar Reconnaissance Orbiter (LRO) that reveal that impacts are transforming the surface much faster than previously thought.
This map shows the distribution of new impact craters (yellow dots) discovered by analyzing 14,000 narrow-angle camera (NAC) temporal pairs. The two red dots mark the location of the March 17, 2013 and September 11, 2013 impacts that were recorded by Earth-based video monitoring. LRO’s mission was recently extended an addition two years through September 2018. Credit: NASA/GSFC/ASUThe LRO’s high resolution camera, which can resolve features down to about 3 feet (1-meter) across, has been peering down at the Moon from orbit since 2009. Taking before and after images, called temporal pairs, scientists have identified 222 impact craters that formed over the past 7 years. The new craters range from 10 feet up to 141 feet (3-43 meters) in diameter.
By analyzing the number of new craters and their size, and the time between each temporal pair, a team of scientists from Arizona State University and Cornell estimated the current cratering rate on the Moon. The result, published in Nature this week, was unexpected: 33% more new craters with diameters of at least 30 feet (10 meters) were found than anticipated by previous cratering models.
LRO before and after images of an impact event on March 17, 2013. The newly formed crater is 59 feet (18 meters) in diameter. Subsurface regolith not exposed to sunlight forms a bright halo around the new crater. There also appears to be a larger nimbus of darker reflectance material visible much further beyond but centered on the impact. Credit: NASA/GSFC/Arizona State University
Similar to the crater that appeared on March 17, 2013 (above), the team also found that new impacts are surrounded by light and dark reflectance patterns related to material ejected during crater formation. Many of the larger impact craters show up to four distinct bright or dark reflectance zones. Nearest to the impact site, there are usually zone of both high and low reflectance. These two zones likely formed as a layer of material that was ejected from the crater during the impact shot outward to about 2½ crater diameters from the rim.
An artist’s illustration of a meteoroid impact on the Moon. Impacts dig up fresh material from below as well as send waves of hot rock vapor and molten rock across the lunar landscape, causing a much faster turnover of the moon soil than previously thought. Credit: NASA
From analyzing multiple impact sites, far flung ejecta patterns wrap around small obstacles like hills and crater rims, indicating the material was traveling nearly parallel to the ground. This kind of path is only possible if the material was ejected at very high speed around 10 miles per second or 36,000 miles per hour! The jet contains vaporized and molten rock that disturb the upper layer of lunar regolith, modifying its reflectance properties.
How LRO creates temporal pairs and scientists use them to discover changes on the moon’s surface.
In addition to discovering impact craters and their fascinating ejecta patterns, the scientists also observed a large number of small surface changes they call ‘splotches’ most likely caused by small, secondary impacts. Dense clusters of these splotches are found around new impact sites suggesting they may be secondary surface changes caused by material thrown out from a nearby primary impact. From 14,000 temporal pairs, the group identified over 47,000 splotches so far.
Here are two examples of a low reflectance (top) and high reflectance (bottom) splotch created either by a small impactor or more likely from secondary ejecta. In either case, the top few inches of the regolith (soil) was churned Credit: NASA/GSFC/Arizona State UniversityBased on estimates of size, depth and frequency of formation, the group estimated that the relentless churning caused by meteoroid impacts will turn over 99% of the lunar surface after about 81,000 years. Keep in mind, we’re talking about the upper regolith, not whole craters and mountain ranges. That’s more than 100 times faster than previous models that only took micrometeorites into account. Instead of millions of years for those astronaut boot prints and rover tracks to disappear, it now appears that they’ll be wiped clean in just tens of thousands!
Everyone on Earth is invited to join the celebration by hosting or attending an InOMN event — and uniting on one day each year to look at and learn about the Moon together. We encourage you to go to InOMN events near you, such as at your local planetariums or museums, or to go out and observe the moon yourself! You can find events near you at the InOMN site. You can also follow the InOMN Twitter feed to see what everyone is doing to celebrate!
Our friends over at CosmoQuest are proud to be partners in this celebration of Earth’s natural satellite. There you can “Observe the Moon” all year long by taking part in lunar-themed activities, such as our Moon Mappers citizen science program, where you’ll get to look at some of the most detailed images taken by the LRO, and help our scientists study the moon and it’s surface. This excellent program is available free of charge, no matter the weather, time of day or your location – you get the best views of the Moon ever!
Take some photos of your activities, whether outdoors observing or indoors mapping craters, and share them online at the CosmoQuest Twitter and Facebook feeds using the hashtag #observethemoon, and CosmoQuest will repost their favorites!
Here are just a few of the media celebrations that have already been posted for InOMN!
“The Moon and More” is a music video starring musicians Javier Colon (Season 1 winner of NBC’s “The Voice”), and Matt Cusson in collaboration with NASA’s Goddard Space Flight Center and the Lunar Reconnaissance Orbiter (LRO) mission.
Credits: NASA’s Goddard Space Flight Center/David Ladd, producer
For years, scientists have been hunting for the stable lava tubes that are believed to exist on the Moon. A remnant from the Moon’s past, when it was still volcanically active, these underground channels could very well be an ideal location for lunar colonies someday. Not only would their thick roofs provide naturally shielding from solar radiation, meteoric impacts, and extremes in temperature. They could also be pressurized to create a breathable environment.
But until now, evidence of their existence has been inferred from surface features such as sinuous rilles – channel-like depressions that run along the surface that indicate the presence of subterranean lava flows – and holes in the surface (aka. “skylights”). However, recent evidence presented at the 47th Lunar and Planetary Science Conference (LPSC) in Texas indicates that one such stable lava tube could exist in the once-active region known as Marius Hills.
NASA has just received a significant boost in the agency’s current budget after both chambers of Congress passed the $1.1 Trillion 2016 omnibus spending bill this morning, Friday, Dec. 18, which funds the US government through the remainder of Fiscal Year 2016.
As part of the omnibus bill, NASA’s approved budget amounts to nearly $19.3 Billion – an outstandingly magnificent result and a remarkable turnaround to some long awaited good news from the decidedly negative outlook earlier this year. Continue reading “NASA Receives Significant Budget Boost for Fiscal Year 2016”
Nearly 47 years ago, the crew of Apollo 8 took an image of planet Earth from the Moon that has been called “the most influential environmental photograph ever taken.” Called Earthrise, the picture represented the first time human eyes saw their homeworld come into view around another planetary body.
Wow, this doesn’t happen very often: Earth and Mars together in one photo. To make the image even more unique, it was taken from lunar orbit by the Lunar Reconnaissance Orbiter. This two-for-one photo was was acquired in a single shot on May 24, 2014, by the Narrow Angle Camera (NAC) on LRO as the spacecraft was turned to face the Earth, instead of its usual view of looking down at the Moon.
The LRO imaging team said seeing the planets together in one image makes the two worlds seem not so far apart, and that the Moon still might have a role to play in future exploration.
“The juxtaposition of Earth and Mars seen from the Moon is a poignant reminder that the Moon would make a convenient waypoint for explorers bound for the fourth planet and beyond!” said the LRO team on their website. “In the near-future, the Moon could serve as a test-bed for construction and resource utilization technologies. Longer-range plans may include the Moon as a resource depot or base of operations for interplanetary activities.”
Watch a video created from this image where it appears you are flying from the Earth to Mars:
The LROC team said this imaging sequence required a significant amount of planning, and that prior to the “conjunction” event, they took practice images of Mars to refine the timing and camera settings.
When the spacecraft captured this image, Earth was about 376,687 kilometers (234,062 miles) away from LRO and Mars was 112.5 million kilometers away. So, Mars was about 300 times farther from the Moon than the Earth.
The NAC is actually two cameras, and each NAC image is built from rows of pixels acquired one after another, and then the left and right images are stitched together to make a complete NAC pair. “If the spacecraft was not moving, the rows of pixels would image the same area over and over; it is the spacecraft motion, combined with fine-tuning of the camera exposure time, that enables the final image, such as this Earth-Mars view,” the LRO team explained.
Check out more about this image on the LRO website, which includes a zoomable, interactive version of the photo.
NASA’s planetary senior review panel harshly criticized the scientific return of the Curiosity rover in a report released yesterday (Sept. 3), saying the mission lacks focus and the team is taking actions that show they think the $2.5-billion mission is “too big to fail.”
While the review did recommend the mission receive more funding — along with the other six NASA extended planetary missions being scrutinized — members recommended making several changes to the mission. One of them would be reducing the distance that Curiosity drives in favor of doing more detailed investigations when it stops.
The role of the senior review, which is held every two years, is to help NASA decide what money should be allocated to its extended missions. This is important, because the agency (as with many other departments) has limited funds and tries to seek a balance between spending money on new missions and keeping older ones going strong.
Engineering acumen means that many missions are now operating well past their expiry dates, such as the Cassini orbiter at Saturn and the Opportunity rover on Mars. In examining the seven missions being reviewed, the panel did recommend keeping funding for all, but said that 4/7 are facing significant problems.
Opportunity rover’s 1st mountain climbing goal is dead ahead in this up close view of Solander Point at Endeavour Crater. Opportunity has ascended the mountain looking for clues indicative of a Martian habitable environment. This navcam panoramic mosaic was assembled from raw images taken on Sol 3385 (Aug 2, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com)
In the case of Curiosity, the panel called out principal investigator John Grotzinger for not showing up in person on two occasions, preferring instead to interact by phone. The review also said there is a “lack of science” in its extended mission proposal with regard to “scientific questions to be answered, testable hypotheses, and proposed measurements and assessment of uncertainties and limitations.”
Other concerns were the small number of samples over the prime and extended missions (13, a “poor science return”), and a lack of clarity on how the ChemCam and Mastcam instruments will play into the extended mission. Additionally, the panel expressed concern that NASA would cut short its observations of clays (which could help answer questions of habitability) in favor of heading to Mount Sharp, the mission’s ultimate science destination.
“In summary, the Curiosity … proposal lacked scientific focus and detail,” the panel concluded, adding in its general recommendations for the reviews that principal investigators must be present to avoid confusion while answering questions. The other missions facing concern from the panel included the Lunar Reconnaissance Orbiter, Mars Express and Mars Odyssey.
Lunar Reconnaissance Orbiter. Image Credit: NASA
LRO: Its extended mission (the second) is supposed to look at how the moon’s surface, subsurface and exosphere changes through processes such as meteorites and interaction with space. The panel was concerned with a “lack of detail” in the proposal and in answers to follow-up questions. The panel also recommended turning off certain instruments “at the end of their useful science mission”.
Mars Express: The extended mission is focusing on the ionosphere and atmosphere as well as the planet’s surface and subsurface. Concerns were raised about matters such as why funding is needed to calibrate its high-resolution stereo camera after 11 years — especially given the instrument has been rarely cited in published journal reports lately — and how people involved in the extended mission would meet the goals. The panel also saw a “lack of communication” in the team.
Mars Odyssey: If approved, the spacecraft will move to the day/night line of Mars to look at the planet’s radiation, gamma rays, distribution of water/carbon dioxide/dust in the atmosphere, and the planet’s surface. The panel, however, said there are no “convincing arguments” as to how the new science relates to the Decadal Survey objectives for planetary science. Odyssey, which is in its 11th year, may also be nearing the end of its productive lifespan given fewer publications using its data in recent years, the panel said.
The panel also weighed in on the success of the Cassini and Opportunity missions:
Artist’s conception of the Mars Odyssey spacecraft. Credit: NASA/JPL
Cassini received the highest rating — “Excellent” — due to its scientific merit, the only mission this time around to do so. The panel was particularly excited about seasonal changes that will be seen on Titan in the coming years, as well as measurements of Saturn’s rings and magnetosphere and its icier moons (such as Enceladus). The spacecraft is noted to be in good condition and the new mission will be a success because of “the unique aspect of the new observations.”
Opportunity, which is more than 10 years into its Mars exploration, is still “in sufficiently good condition” to do science, although the panel raised concerns about software and communication problems. The panel, however, said more time with the rover would allow it to look for evidence of past water on Mars that would not be visible from orbit — even though it’s unclear if phyllosilicates around its current location (Endeavour crater) are from the Noachian period, the earliest period in Mars’ history.
The panel is just one step along the road to figuring out how NASA chooses to spend its money in the coming years. Funding availability depends on how much money Congress allocates to the agency.
Forty-five years ago yesterday, the Sea of Tranquility saw a brief flurry of activity when Neil Armstrong and Buzz Aldrin dared to disturb the ancient lunar dust. Now the site has lain quiet, untouched, for almost half a century. Are any traces of the astronauts still visible?
The answer is yes! Look at the picture above of the site taken in 2012, two years ago. Because erosion is a very gradual process on the moon — it generally takes millions of years for meteors and the sun’s activity to weather features away — the footprints of the Apollo 11 crew have a semi-immortality. That’s also true of the other five crews that made it to the moon’s surface.
In honor of the big anniversary, here are a few of NASA’s Lunar Reconnaissance Orbiter’s pictures of the landing sites of Apollo 11, Apollo 12, Apollo 14, Apollo 15, Apollo 16 and Apollo 17. (Apollo 13 was slated to land on the moon, but that was called off after an explosion in its service module.)
The Apollo 12 and Surveyor 3 landing sites in the Ocean of Storms on the moon. Visible is the descent stage of Intrepid (the lunar module) and the robotic craft Surveyor 3, which the astronauts took a sample from while they were on the surface. Also labelled are craters the astronauts visited. Credit: NASA/Goddard/Arizona State UniversityThe Apollo 14 landing site at Fra Mauro, imaged by the Lunar Reconnaissance Orbiter in 2011. At right is the descent stage of Antares, the lunar module. At far left, beside the cart tracks and marked by an arrow, is the Apollo Lunar Surface Experiment Package. Credit: NASA/GSFC/Arizona State UniversityThe Apollo 15 landing site at Hadley plains, taken by the Lunar Reconnaissance Orbiter from an altitude of 15.5 miles (25 kilometers) in 2012. Visible is the descent stage of Falcon (the lunar module), the Lunar Roving Vehicle (LRV) and the Apollo Lunar Surface Experiment Package (ALSEP). The site is marked by rover tracks. Credit: NASA Goddard/Arizona State UniversityThe Apollo 16 landing site in the Descartes Highlands, taken by the Lunar Reconnaissance Orbiter in 2010. Visible is the descent stage of lunar module (LM) Orion, the “parking spot” of the Lunar Roving Vehicle (LRV) and its tracks, the Apollo Lunar Science Experiment Package (ALSEP), a radioisotope generator (RTG) and the geophone line, which is part of the mission’s Active Seismic Experiment. Credit: NASA’s Goddard Space Flight Center/Arizona State UniversityThe Apollo 17 landing site at Taurus-Littrow taken by the Lunar Reconnaissance Orbiter in 2011. Visible is the descent stage of the lunar module Challenger, the Lunar Roving Vehicle (LRV) and its tracks, the Apollo Lunar Surface Experiment Package (ALSEP) and Geophone Rock. Credit: NASA’s Goddard Space Flight Center/ASU
If you’re a fan of moon observation, it’s lucky for you that spacecraft such as the Lunar Reconnaissance Orbiter exist. For about the past five years, the NASA spacecraft has been in orbit around a closest large neighbor, taking images of the surface in high-definition.
To celebrate LRO’s fifth anniversary, NASA is asking members of the public to vote on which of those images (above) is their favorite. This isn’t so much a statement about the scientific data it has collected, NASA said, but more appreciating the images as art.
Voting runs from May 23 to June 6, and the winner will be announced with the full collection’s release on June 18 — the actual official fifth anniversary of the launch. You can find more information about the vote at this page.
By the way, LRO not only takes good pictures of the moon, but also of other spacecraft. You can check out its pictures of LADEE and Chang’e-3 in these past Universe Today articles.
Meanwhile, James Garvin — NASA’s chief scientist of the sciences and exploration directorate — eloquently weighs in below on his favorite images of the moon. His description of Aristarchus is interesting: “Here is Mother Nature’s expression of a gigantic landform made by a cosmic collision.” You can check out the other four below.
While people across North America marvelled at the blood-red moon early this morning, some NASA engineers had a different topic on their minds: making sure the Lunar Reconnaissance Orbiter would survive the period of extended shadow during the eclipse.
LRO uses solar panels to get energy for its batteries, so for two passes through the Earth’s shadow it would not be able to get any sunlight at all. Tweets on the official account show all as well in the first few hours after the eclipse.
“The spacecraft will be going straight from the moon’s shadow to the Earth’s shadow while it orbits during the eclipse,” stated Noah Petro, LRO’s deputy project scientist at NASA’s Goddard Space Flight Center, in a release before the eclipse occurred.
“We’re taking precautions to make sure everything is fine,” Petro added. “We’re turning off the instruments and will monitor the spacecraft every few hours when it’s visible from Earth.”
LRO’s Twitter account asked “Who turned off the heat and lights?” during the eclipse, then reported a happy acquisition of signal after the shadow passed by. “AOS, and sunlight, sweet sunlight! My batteries are charging again before I make another trip to the lunar far side.”
Hear more about LRO’s eclipse journey in the video below. For more information, check out NASA’s LRO website. UPDATE, 10:28 a.m. EDT: NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft also is fine after the eclipse, according to its Twitter account.
![Distribution of new impact craters (yellow dots) discovered by analyzing 14,000 NAC temporal pairs. The two red dots mark the location of the 17 March 2013 and the 11 September 2013 impacts that were recorded by Earth-based video monitoring [NASA/GSFC/Arizona State University]](https://www.universetoday.com/wp-content/uploads/2016/10/Moon-new-crater-distribution-NASA-GSFC-ASU.jpg)
![Example of a low reflectance (top) and high reflectance (bottom) splotch created either by a small impactor or more likely from secondary ejecta. In either case, the top few centimeters of the regolith (soil) was churned [NASA/GSFC/Arizona State University].](https://www.universetoday.com/wp-content/uploads/2016/10/Moon-craters-splotches-NASA.gif)
