Tag: Moon

The central peaks of Compton Crater

2:08 pm

Central peaks of Compton Crater

Cool image time! The Lunar Reconnaissance Orbiter (LRO) science team today released a beautiful oblique image looking of the central peaks of Compton Crater, a far side crater with a floor that is fractured and is one of about 200 hundred such craters.

Today’s Featured Image highlights an floor-fractured crater (FFC) that could tell us much about the lunar crust. An asteroid or comet impact is thought to have excavated 146.6-kilometer-wide Compton crater about 3.85 billion years ago. Igneous intrusion or viscous relaxation — or perhaps both processes — subsequently produced branching fractures and small basalt plains within Compton crater. The latter are darker than their surroundings.

Unlike Copernicus Crater, the surface appears smooth. Go to the link and zoom in to see what I mean. All the fractures appear very large and filled in. Of course, that could be because of the image’s resolution, and that other images might show more details and pits.

I find the central peaks more intriguing, however. It appears that, following their formation they were hit by several bolides, one of which carved a gigantic deep hole into those peaks.

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Chandrayaan-2 likely delayed to July

9:05 am

The new colonial movement: The launch of India’s first lunar lander/rover, Chandrayaan-2, will likely be delayed again, from May until July.

This further delay is not confirmed by ISRO, India’s space agency. Nor is any clear reason given in the article above to explain this additional delay.

It would not surprise me however. The head of ISRO, K. Sivan, is a trained engineer. He has shown himself to be very willing to impose delays if he has any doubts about the success of the mission.

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Beresheet’s first pictures of the Moon

1:46 pm

Beresheet looks at the Moon

The new colonial movement: The privately built Israeli planetary probe Beresheet, now in lunar orbit, has released its first pictures of the Moon.

The image on the right is one of those images, cropped to post here, and was taken from about 300 miles altitude. The link has a second image showing the Moon with the Earth in the distance. The resolution of both images is quite impressive.

The landing is scheduled for April 11. Stay tuned!

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Chandrayaan-2’s new delay is due to damage during test

9:38 am

The new colonial movement: It appears the reason for the new delay in the launch of India’s Chandrayaan-2 lunar lander is that the spacecraft suffered minor damage during a landing test.

A source in the know, said: “The rover and orbiter are in good health and tests met all the parameters. However, after the ‘Lander Drop Test’, we found that Vikram (the lander) needed to be strengthened in its legs. Prima facie, it appears that not all parameters were set correctly before the test, it could also be that the additional mass—a result of the new configuration—caused the problem.”

They still seem determined to launch in May, though I suspect this is not realistic. It depends on exactly when this test occurred. The article does not say, and if it occurred several months ago then the May date might make sense. Otherwise, expect further delays.

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Beresheet enters lunar orbit

9:02 am

The privately-built lunar lander Beresheet today successfully entered lunar orbit.

They achieved this by completing an engine burn that changed their Earth orbit to an elliptical lunar one.

At 5:18 p.m. Israel time on April 4, the spacecraft’s engine activated for six minutes and reduced its speed by 1,000 km/hour, from 8,500 km/hour to 7,500 km/hour, relative to the moon’s velocity. The maneuver was conducted with full communication between Beresheet’s control room in Israel and the spacecraft, and signals in real time match the correct course. In the coming week, with expected intense engineering activities, many more maneuvers will take Beresheet from an elliptical to a round orbit, at a height of 200 km. from the moon. The maneuvers will aim to reduce the spacecraft’s distance from the moon and reach the optimal point to conduct an autonomic landing in the Sea of Serenity in the evening Israel time, April 11.

You can see a video of their mission control at the completion of this burn here.

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Beresheet makes course adjustment just prior to entering lunar orbit

8:59 am

Earth as seen by Beresheet

The Israeli privately-funded lunar lander Beresheet yesterday completed a one-minute engine burn to adjust its course slightly in preparation for entering lunar orbit on April 4.

This morning’s 72-second-long burn helped make some “final adjustments” ahead of capture into lunar orbit, mission team members said in an update this morning. It’s unclear if any further such tweaks will be needed. “The teams are assessing the results to determine if another alignment will be required before Beresheet enters the lunar orbit this Thursday,” project team members said.

The image to the right was taken by Beresheet of the Earth during its last close approach on March 31. It appropriately shows the Middle East, with the Arabian peninsula visible just below center.

The landing is still scheduled for April 11.

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Yutu-2 and Chang’e-4 awake for fourth lunar day

8:43 am

The Chinese rover Yutu-2 and lander Chang’e-4 were awakened on March 30, 2019 to begin work for their fourth lunar day on the surface of the Moon’s far side.

The rover was designed to last for three lunar days, but much like NASA missions that regularly outlive their initial mandates, Yutu 2’s mission may stretch on longer, the Chinese space agency hopes. (The current rover’s predecessor, Yutu, lost its roving ability on its second day on the moon.)

The China Lunar Exploration Program, which heads up the mission, has not provided any details about its scientific plans for the fourth day of Chang’e 4, which is focused on exploring the far side of the moon and how it differs from the near side.

Based on the images taken by Lunar Reconnaissance Orbiter, it appears they will be heading west, following the smoothest route away from Chang’e-4. This will place Yutu-2 in an area of small craters.

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Yutu-2 heads west!

10:28 am

LRO images of Yutu-2 on the Moon
Click for full image.

A new image from Lunar Reconnaissance Orbiter (LRO) shows the path taken by the Chinese lunar rover Yutu-2 during its second lunar day of travel on the Moon. The LRO images on the right, cropped and reduced in resolution to show here, compares the rovers position at the start and end of February. The white arrow indicates the rover, with its Chang’e-4 lander visible between the three craters to the east. As noted by the LRO science team:

LRO passes over any given place on the Moon at least once every month (in the daylight), allowing the westward progress of the Yutu-2 rover to be seen. At the end of February, Yutu-2 was 69 meters from it’s home base, the Chang’e 4 lander; LROC images show Yutu-2 made 46 meters of westward progress during the month of February.

It appears from these orbital images that they are taking the smoothest route, with the fewest obstacles, away from the lander.

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China’s future lunar exploration plans

9:46 am

In a poster presented on Tuesday at this week’s 50th Lunar and Planetary Science Conference in Texas, China outlined its future plans for lunar exploration.

Systematically considering the major scientific issues of the Moon and the lunar in-situ utilization resources, Chinese scientists and technical experts have proposed a vision to preliminarily build a research station on the Moon’s South Pole by implementing 3-4 missions before 2035.

The first mission will carry out a comprehensive exploration in the South Pole of the Moon, including the topography, elemental composition and volatile contents of the Moon, and the information on the structure of the South Pole from shallow to deep levels. Water (ice) in the permanent shadow area was detected in-situ to reveal the content, distribution and source of water and volatiles on the surface of the Moon. After that, a sampling return mission will be arranged to collect samples from the South Pole of the Moon and return them to the Earth. In addition to the scientific exploration of the Moon, the utilization of lunar resources should also be taken into consideration. In later missions, lunar platforms will be used to make astronomical or earth observations and to consider the use of lunar resources. [emphasis mine]

China clearly intends to put its footprints on the Moon. It is not fiddling around with an orbital lunar station, as it looks like we are with NASA’s Gateway project. While China explores the surface, we will be stuck in orbit (maybe).

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Test drone maps ice cave in Iceland

10:23 am

Engineers have tested a prototype lidar-equipped drone by flying it through a lava tube in Iceland and using it to automatically map the tube.

While a cave-exploring drone on Earth may use propellers, free-flying spacecraft exploring caves on the Moon, where there is practically no atmosphere, or in the thin air of high altitude lava tubes on Mars’ giant volcanoes, would have to use small thrusters. The mission of the terrestrial drone deployed at the Lofthellir Ice Cave focused on validating the idea of using a drone-equipped LiDAR to safely navigate and accurately map rock and ice inside a dark lava tube in the absence of GPS or any prior map.

Under a research contract with NASA, Astrobotic has developed a custom navigation software product, known as AstroNav, to give drones and small free-flying spacecraft the ability to autonomously explore and map subterranean environments. AstroNav employs both stereo vision and LiDAR, works without GPS or previously stored maps, and can operate in real-time while a novel environment is explored at a high rate of speed.

…”The Astrobotic drone and LiDAR performed exactly as we had hoped, and was able to help us map the Lofthellir Lava Tube in 3D within minutes” says Lee. “We now have a highly accurate model of the shape and dimensions of the cave, and of the configuration of its many rocky and icy features, such as rock falls, ice columns, and micro-glaciers.”

The concept is an excellent one, especially for exploring the caves and pits of Mars. This test however only checked out the lidar. A drone that could do this on either Mars or the Moon does not yet exist.

I have posted their video of the flight below the fold.

Note: Thanks to reader Eddie Willers for noting that I mistakenly located this research in Greenland, not Iceland. Post now corrected.
» Read more

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Chinese lunar rover and lander enter their third lunar night

9:21 am

The Chinese lunar rover Yutu-2 and its lander Chang’e-4 have gone into hibernation as they enter their third lunar night on the far side of the Moon.

According to Chinese news reports, both spacecraft have now exceeded their nominal lifespan.

With all systems and payloads operating well, the Yutu-2 team will continue roving and science data collection on lunar day 4 of the Chang’e-4 mission, according to a [Chinese] announcement.

Yutu-2 added 43 meters to its overall drive distance in its third day of activities, continuing a path to the northwest of the landing site, which was recently named ‘Statio Tianhe’ by the International Astronomical Union. The rover just covered seven meters between waking for lunar day 3 on Feb. 28 and Mar. 3, during which time it navigated carefully toward a 20 centimeter diameter rock in order to analyze the specimen with an infrared and visible light spectrometer to determine its origin.

I am struck by how tentative the Chinese and their rover appear. The first Russian lunar rover, Luna 17, traveled 6.5 miles in eleven months. The second, Luna 21, traveled 23 miles in four months. At the pace Yutu-2 is setting, it will not come close to these mileages. Moreover, my impression of Chinese space technology in the past decade has been that it is quite robust. This tentativeness thus surprises me. Maybe because this is a government project they are simply covering their butts should something go wrong, and thus making believe the rover is more delicate than it really is.

As Scotty on Star Trek once said, “Always under predict, then over perform.” We might be seeing that pattern here.

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The travels of Moon’s scarce surface water

9:19 am

An analysis of data from one of Lunar Reconnaissance Orbiter’s (LRO) instruments have allowed scientists to map the movements of the scarce water on the lunar surface.

Up until the last decade or so, scientists thought the Moon was arid, with any water existing mainly as pockets of ice in permanently shaded craters near the poles. More recently, scientists have identified surface water in sparse populations of molecules bound to the lunar soil, or regolith. The amount and locations vary based on the time of day. This water is more common at higher latitudes and tends to hop around as the surface heats up.

…Water molecules remain tightly bound to the regolith until surface temperatures peak near lunar noon. Then, molecules thermally desorb and can bounce to a nearby location that is cold enough for the molecule to stick or populate the Moon’s extremely tenuous atmosphere, or “exosphere”, until temperatures drop and the molecules return to the surface.

The quantities we are talking about here are very tiny. This will not be the water that future settlers will depend on. Instead, it will be those pockets of ice in the permanently shaded craters.

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Beresheet sends back first pictures

7:35 am

The privately-built Israeli lunar lander Beresheet has sent back its first pictures, taken on its way to the moon.

The picture, taken 37,600 km from Earth, shows the Israeli flag and the inscription with “Am Yisrael Hai” (the People of Israel Live) in Hebrew and the inscription “Small Country, Big Dreams” in English. The spacecraft was snapped as it passed over Australia, and the photograph was taken during a very slow rotation by Beresheet. The Israeli spacecraft, built in an IAI factory, is in an elliptical orbit around Earth – its greatest distance from Earth (the apogee) at this stage is some 131,000 kilometers.

While the press wants to trivialize this image by calling it a selfie, it was taken for very important engineering reasons. It demonstrates that the camera and the spacecraft’s pointing systems are working, exactly as planned.

Beresheet will continue to raise the apogee of its orbit until it enters the Moon’s gravitational sphere of influence, when it will then shift into lunar orbit.

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Beresheet successfully completes engine burn

8:39 am

After a computer issue prevented its last course correction, Beresheet, the Israeli private lunar probe, successfully completed that engine burn yesterday, raising its Earth orbit’s apogee to 81,000 miles, almost a third of the way to the Moon.

The Beresheet team has not explained exactly what went wrong with the computer earlier this week, or what they have done to fix the problem. All they said is that they have figured it out and worked around it.

The next engine burn to raise the orbit further will occur in about a week.

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Beresheet’s second engine burn stopped by computer reset

8:40 am

It appears that the second engine burn to raise the orbit of Israel’s privately built lunar lander, Beresheet, did not happen as planned because of an unexpected computer reboot.

In a statement Tuesday morning, SpaceIL and Israel Aerospace Industries (IAI) engineers said they were investigating the malfunction, but said that other than a known problem with the navigation system’s star tracker, the Beresheet’s systems were all functioning properly.

The maneuver was scheduled to take place Monday night, as the spacecraft passed near the Earth in an area where the Ramat Gan-based SpaceIL ground crew would not be in direct communication with the craft.

During the pre-maneuver phase, the spacecraft computer reset unexpectedly, and the maneuver was automatically cancelled.

The question that immediately comes to mind: Did they purchase a space-hardened computer? Cosmic rays can wreck havoc on computer memory, causing just this type of unexpected reset, so computers in space need to be much better shielded than on Earth.

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SpaceX successfully launches three satellites

7:02 pm

Capitalism in space: SpaceX tonight used its Falcon 9 rocket, including a first stage that had already flown twice before, to launch an Indonesian communications satellite, an Air Force smallsat, and most importantly, the Israeli-built Beresheet lunar lander, the first planetary mission entirely funded from private sources.

You can get some details about Beresheet here. If all goes as planned, it will land on the Moon on April 11 and operate for two Earth days on the surface.

SpaceX was also able to successfully land that first stage, which I think is the first time they have successfully used and recovered a first stage three times. Look for this first stage to fly a fourth time.

The 2019 launch race:

2 China
2 SpaceX
1 ULA
1 Japan
1 India
1 Europe
1 Russia

The U.S. now leads China in the national rankings, 3-2.

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NASA selects experiments it wants to put on commercial lunar spacecraft

4:51 pm

Capitalism in space: NASA has selected a dozen experiments/instruments it wants to put on private commercial lunar spacecraft, either landers or rovers.

According to the press release, some of these could fly as early as before the end of this year. If so, I suspect they will go on one of the finalists for the Google Lunar X-prize, some of whom are planning to fly this year.

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New LRO image of Chang’e-4 and Yutu-2

10:05 am

Chang'e-4 and Yutu-2

The Lunar Reconnaissance Orbiter (LRO) science team has released its third and best image of the Chinese Chang’e-4 lander and Yutu-2 rover. The image on the right is a full resolution cropped section, with the lander on the bottom and the rover above and to the left.

Just after midnight (UTC) on 1 February 2019 LRO passed nearly overhead the Chang’e 4 landing site. From an altitude of 82 kilometers the LROC Narrow Angle Camera pixel scale was 0.85 meters (33 inches), allowing a sharper view of the lander and Yutu-2 rover. At the time the rover was 29 meters northwest of the lander, but the rover has likely moved since the image was acquired. This view has close to the smallest pixel size possible in the current LRO orbit. In the future however, LROC will continue to image the site as the lighting changes and the rover roves!

These future LRO images will allow us to track Yutu-2 and get an idea of its research, even if the Chinese do not release any information.

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NASA to put humans on the Moon soon!

3:11 pm

Wanna bet? According to NASA officials, the agency is accelerating its manned effort and expects to return to the Moon with humans by 2028 at the latest!

Jim Bridenstine, NASA’s administrator, told reporters Thursday that the agency plans to speed up plans backed by President Donald Trump to return to the moon, using private companies.

“It’s important that we get back to the moon as fast as possible,” said Bridenstine in a meeting at NASA’s Washington headquarters, adding he hoped to have astronauts back there by 2028.

“This time, when we go to the Moon, we’re actually going to stay. We’re not going to leave flags and footprints and then come home to not go back for another 50 years” he said.

Why does this announcement remind me of similar enthusiastic predictions made by Russia’s space agency, Roscosmos, all of which have never come true? In fact, why does Bridenstine’s prediction remind me of many past NASA predictions since the 1980s, all of which either never happened, or happened decades behind schedule and in a manner that was far from grand?

If NASA is the agency to run this program, this prediction will not happen, period. For NASA to get back to the Moon by 2028 would require them to somehow build Gateway (which Bridenstine labels as a key component in this program) while also accelerating the launch schedule of SLS, a rocket NASA has spent fifteen years building that it doesn’t expect to launch for at least two more years, and will not put humans on it until 2024, at the earliest.

Gateway has not even been funded. It provides no way to get to the lunar surface. If it is funded it will cost billions, and likely take as long to build as SLS. SLS itself is expensive, unwieldy, and incapable of providing launch services for such an ambitious program.

Bridenstine’s announcement though did contain a ray of hope. He and his associates made a big deal about how they wish to hire many different private companies to achieve their goals. If the agency gets out of the way and lets free Americans do the job, then maybe it will happen.

We shall see. NASA’s track record when it comes to letting privately-built manned commercial spacecraft do the job is dismal, and that’s being kind.

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IAU approves China’s proposed names for Chang’e-4 landing site

10:07 am

That was fast! The International Astronomical Union (IAU) has approved all of the proposed names that China submitted for the features at or near Chang’e-4 landing site.

The IAU Working Group for Planetary System Nomenclature has approved the name Statio Tianhe for the landing site where the Chinese spacecraft Chang’e-4 touched down on 3 January this year, in the first-ever landing on the far side of the Moon. The name Tianhe originates from the ancient Chinese name for the Milky Way, which was the sky river that separated Niulang and Zhinyu in the folk tale “The Cowherd and the Weaver Girl”.

Four other names for features near the landing site have also been approved. In keeping with the theme of the above-mentioned folk tale, three small craters that form a triangle around the landing site have been named Zhinyu, Hegu, and Tianjin, which correspond to characters in the tale. They are also names of ancient Chinese constellations from the time of the Han dynasty. The fifth approved name is Mons Tai, assigned to the central peak of the crater Von Kármán, in which the landing occurred. Mons Tai is named for Mount Tai, a mountain in Shandong, China, and is about 46 km to the northwest of the Chang’e-4 landing site.

Compare this fast action with the IAU’s approval process for the names the New Horizons team picked for both Pluto and Ultima Thule. It took the IAU more than two years to approve the Pluto names, and almost three years to approve the Charon names. It is now almost two months after New Horizons’ fly-by of Ultima Thule, and the IAU has not yet approved the team’s picks for that body.

Yet it is able to get China’s picks approved in less than a month? Though it is obviously possible that there is a simple and innocent explanation for the differences here, I think this illustrates well the biases of the IAU. Its membership does not like the United States, and works to stymie our achievements if it can. This factor played a part in the Pluto/planet fiasco. It played a part in its decision to rename Hubble’s Law. And according to my sources, it was part of the background negotiations in the naming of some lunar craters last year to honor the Apollo 8 astronauts.

The bottom line remains: The IAU has continually tried to expand its naming authority, when all it was originally asked to do was to coordinate the naming of distant astronomical objects. Now it claims it has the right to approve the naming of every boulder and rock anywhere in the universe. At some point the actual explorers are going to have to tell this organization to go jump in a lake.

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Chang’e-4 & Yutu-2 enter sleep mode for second lunar night

9:40 am

The Chinese lunar lander Chang’e-4 and its rover Yutu-2 have both gone into hibernation as part of their preparation for surviving their second night on the Moon’s surface.

The Yutu-2 rover and lander will resume science and exploration activities on Feb. 28 and March 1, respectively, according to the release, with the rover needing to unfold solar panels and dissipate heat.

The previous lunar night saw the Chang’e-4 lander record a temperature low of -190 degrees Celsius (-310 Fahrenheit), with measurements made possible by a Russian-developed radioisotope thermoelectric generator which also acts as a prototype for future deep-space exploration.

Official updates on the progress of the mission had been sparse during the second lunar day of operations, though some new images and footage were released ahead of the Chinese New Year holiday, which ran from Feb. 4 to Feb. 10.

Yutu-2 has traveled about 400 feet so far.

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LRO spots Chinese lunar rover

10:31 am

Yutu-2 and Chang'e-4 on far side of Moon

The Lunar Reconnaissance Orbiter (LRO) science team has now released a second and closer image of Chang’e-4’s location on the far side of the Moon, which now also shows the nearby rover Yutu-2.

The two arrows in the image to the right, cropped to post here, show both. The rover is the dot on the right, with the lander to the left, both just beyond the arrow tips. Both are very small, with Yutu-2 for example only two pixels across. Still, with both you can see their shadows, equally small, to the left of both bright dots. With sunlight coming from the right, all the craters, which are recessed, have their shadows on the right. The spacecraft, sticking up from the surface, have shadows going to the the left.

As Yutu-2 continues its travels, LRO will likely take more images, allowing us to track it even if the Chinese provide limited information.

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Chinese cubesat snaps picture of Earth and Moon from deep space

9:21 am

The Moon and Earth

A interplanetary cubesat, Longjiang-2, launched with China’s communications relay satellite that they are using to communicate with Chang’e-4 and Yutu-2 on the far side of the Moon, has successfully taken a picture of both the Moon and Earth, as shown in the picture on the right.

Longjiang-2 is confirming what the MarCo cubesats proved from Mars, that cubesats can do interplanetary work.

And the picture is cool also. This was taken on February 3, when the entire face of the Moon’s far side is facing the Sun, illuminating it all. This timing also meant that the globe of the Earth would be entirely lit.

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LRO photographs Chang’e-4 on lunar surface

9:00 am

Chang'e-4 on the lunar surface

The Lunar Reconnaissance Orbiter (LRO) science team has released a spectacular oblique image that shows Chang’e-4 on the floor of Von Kármán crater.

Four weeks later (30 January 2019), as LRO approached the crater from the east, it rolled 70° to the west to snap this spectacular view looking across the floor towards the west wall. Because LRO was 330 kilometers (205 miles) to the east of the landing site, the Chang’e 4 lander is only about two pixels across (bright spot between the two arrows), and the small rover is not detectable. The massive mountain range in the background is the west wall of Von Kármán crater, rising more than 3000 meters (9850 feet) above the floor.

The image on the right has been reduced to post here. If you click on it you can see a larger version, but you need to download a very large file at the above link to see it at full resolution.

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Plato Crater on the Moon

11:47 am

Plato Crater's west rim

Cool image time! The Lunar Reconnaissance Orbiter (LRO) science team this week released a new high resolution image of the western rim of 63-mile-wide Plato Crater, located near the visible edge of the Moon’s near side. On the right is a slightly reduced version cropped to show the area of most interest.

Plato crater is prominent, yet from our vantage point on Earth we never truly see it as it is. That’s because it is located far enough north of the lunar equator (center latitude 51.62°N, center longitude 350.62°E) on the curving surface of the spherical Moon that it appears foreshortened. Plato is round like most other impact craters, but from Earth we see it as an oval aligned east to west.

A dark floor makes 101-kilometer-wide Plato crater stand out against a light-colored lunar highlands background. Plato crater is also prominent by association; the crater is located just north of 1145-kilometer-wide Mare Imbrium. A small part of this mare is visible at lower left in our Featured Image. Mare Imbrium is made up of many basalt layers laid down by violent volcanic episodes over a span of about 1.5 billion years. The basalts fill the Imbrium Basin, which a large asteroid or comet impact excavated about 3.85 billion years ago. When we look at a bright full Moon, round dark Mare Imbrium captures our gaze, then we see Plato crater, which is estimated to be about a hundred million years younger than the Imbrium Basin.

The western rim of Plato crater — visible on the east (right) side of our Featured Image — includes a 23.4-kilometer-wide slump block. The roughly triangular piece of rim broke free when an asteroid impact excavated Plato crater. Its eastern edge stands up to 1.4 kilometers above the crater’s dark floor. Part of the floor is visible in the image just above right center, east of the long shadow of the rim. [emphasis mine]

That block is thus 14.5 miles wide, and almost a mile high. I am trying to imagine what it was like when it broke off the rim and fell eastward into the crater floor. I am having trouble doing so.

Below is a image of the entire crater, with the area of the image above indicated by a white box. It shows clearly how this crater splashed into the basalt lava plain of Mare Imbrium.
» Read more

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Rock from Earth, found on Moon?

2:24 pm

The uncertainty of science: Scientists studying rocks brought back by the Apollo 14 lunar mission have concluded that one sample originally came from the Earth, and if so would be the oldest known Earth rock.

It is possible that the sample is not of terrestrial origin, but instead crystallized on the Moon, however, that would require conditions never before inferred from lunar samples. It would require the sample to have formed at tremendous depths, in the lunar mantle, where very different rock compositions are anticipated. Therefore, the simplest interpretation is that the sample came from Earth.

The team’s analyses are providing additional details about the sample’s history. The rock crystallized about 20 kilometers beneath Earth’s surface 4.0-4.1 billion years ago. It was then excavated by one or more large impact events and launched into cis-lunar space. Previous work by the team showed that impacting asteroids at that time were producing craters thousands of kilometers in diameter on Earth, sufficiently large to bring material from those depths to the surface. Once the sample reached the lunar surface, it was affected by several other impact events, one of which partially melted it 3.9 billion years ago, and which probably buried it beneath the surface. The sample is therefore a relic of an intense period of bombardment that shaped the Solar System during the first billion years. After that period, the Moon was affected by smaller and less frequent impact events. The final impact event to affect this sample occurred about 26 million years ago, when an impacting asteroid hit the Moon, producing the small 340 meter-diameter Cone Crater, and excavating the sample back onto the lunar surface where astronauts collected it almost exactly 48 years ago (January 31–February 6, 1971).

The scientists also admit that their conclusion is controversial and will be disputed. If true, however, it suggests that there is significant material on the Moon from the early Earth that can provide a window into parts our planet’s history that are presently inaccessible.

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Moon hit by small meteorite during eclipse

12:57 pm

During the lunar eclipse two days ago on January 20, 2018 amateur astronomers were able to record the impact of a small meteorite.

The MIDAS survey is a Moon-watching that scours video of its surface in the hopes of detecting the tiny flashes associated with meteorite impacts. In this case, MIDAS scored a home run, and it was the first time the system was able to spot an impact during a total lunar eclipse.

“In total I spent almost two days without sleeping, including the monitoring time during the eclipse,” [Jose] Madiedo explained to Gizmodo. “I was exhausted when the eclipse ended—but when the automatic detection software notified me of a bright flash, I jumped out of my chair. It was a very exciting moment because I knew such a thing had never been recorded before.”

The meteorite itself wasn’t terribly large, and is estimated to have only been around 22 pounds.

I have embedded the video of the impact below the fold. It is very short, and the flash is not very impressive, but it still is quite cool.
» Read more

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Planetary rover update: January 22, 2019

12:06 pm

Summary: Curiosity begins journey off of Vera Rubin Ridge. Opportunity’s silence is now more than seven months long, with new dust storms arriving. Yutu-2 begins roving the Moon’s far side.

Before providing today’s update, I have decided to provide links to all the updates that have taken place since I provided a full list in my February 8, 2018 update. As I noted then, this allows my new readers to catch up and have a better understanding of where each rover is, where each is heading, and what fascinating things they have seen in the past few years.

These updates began when I decided to figure out the overall context of Curiosity’s travels, which resulted in my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. Then, when Curiosity started to travel through the fascinating and rough Murray Buttes terrain in the summer of 2016, I stated to post regular updates. To understand the press releases from NASA on the rover’s discoveries it is really necessary to understand the larger picture, which is what these updates provide. Soon, I added Opportunity to the updates, with the larger context of its recent travels along the rim of Endeavour Crater explained in my May 15, 2017 rover update.

Now an update of what has happened since November!
» Read more

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