Moon Archives

May 4, 2012December 23, 2015 by Nancy Atkinson

How the Hubble Telescope Will Look at the Moon to See Venus Transit the Sun

Scientists used the Hubble Space Telescope to look at the Moon to prepare for special observations of the 2012 Venus transit of the Sun. Credit: NASA, ESA, and D. Ehrenreich (Institut de Planetologie et d'Astrophysique de Grenoble (IPAG)/CNRS/Universite Joseph Fourier)

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Venus moving across the face of the Sun, from our vantage point here on Earth, is such a rare event, that astronomers and observatories around the world have been preparing for this year’s Venus Transit, on June 5-6. And one observatory that is literally “around the world,” – the Hubble Space Telescope — is even planning to make observations of this transit event. What, you say? The Hubble telescope can’t look at the Sun – it would fry every component on board! Hubble scientists are being pretty sneaky, if not resourceful so they too can join in the observations.

Since Hubble can’t look at the Sun directly, astronomers are planning to point the telescope at the Moon, using it as a mirror to capture reflected sunlight and isolate the small fraction of the light that passes through Venus’s atmosphere. Imprinted on that small amount of light are the fingerprints of the planet’s atmospheric makeup.

Scientists say these observations will mimic a technique that is already being used to sample the atmospheres of giant planets outside our solar system passing in front of their stars. In the case of the Venus transit observations, astronomers already know the chemical makeup of Venus’s atmosphere, and that it does not show signs of life on the planet. But the Venus transit will be used to test whether this technique will have a chance of detecting the very faint fingerprints of an Earth-like planet, even one that might be habitable for life, outside our solar system that similarly transits its own star.

Venus is an excellent stand in for Earth because of how similar in size and mass it is to our planet.

Several different instruments on Hubble will be used in this special observation. The Advanced Camera for Surveys, Wide Field Camera 3, and Space Telescope Imaging Spectrograph, to view the transit in a range of wavelengths, from ultraviolet to near-infrared light. During the transit, Hubble will snap images and perform spectroscopy, dividing the sunlight into its constituent colors, which could yield information about the makeup of Venus’s atmosphere.

Hubble will observe the Moon for seven hours, before, during, and after the transit so the astronomers can compare the data. Astronomers need the long observation because they are looking for extremely faint spectral signatures. Only 1/100,000th of the sunlight will filter through Venus’s atmosphere and be reflected off the Moon.

Because the astronomers only have one shot at observing the transit, they had to carefully plan how the study would be carried out. Part of their planning included the test observations of the Moon, such as when they took the top image of Tycho Crater.

Hubble will need to be locked onto the same location on the Moon for more than seven hours, the transit’s duration. For roughly 40 minutes of each 96-minute orbit of Hubble around the Earth, the Earth occults Hubble’s view of the Moon. So, during the test observations, the astronomers wanted to make sure they could point Hubble to precisely the same target area.

This is the last time this century sky watchers can view Venus passing in front of the Sun. The next transit won’t happen until 2117. Venus transits occur in pairs, separated by eight years. The last event was witnessed in 2004.

Find more on how you can observe the Venus transit for yourself in this article by Tammy Plotner.

Source: HubbleSite

May 4, 2012December 23, 2015 by Nancy Atkinson

Moon Craters 3-D!

A young unnamed crater on the Moon west of Isaev crater. Credit: NASA/GSFC/Arizona State University; Anaglyph by Nathanial Burton-Bradford.

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While many are hoping to see a larger-than-usual view of the Moon this weekend, here’s some great 3-D closeups courtesy of the Lunar Reconnaissance Orbiter and imaging wizard Nathanial Burton Bradford. This great 3-D view (Red/Cyan glasses needed) shows quite an interesting young impact crater on the Moon, (17.682°S, 144.408°E) west of Isaev crater. Click on the image for a larger view, and in 3-D you can dive right in and see all the nooks and crannies – what scientists call complex crater morphology.

Below you can view a Digital Terrain Model, or DTM of this same crater, and find the specifics of how deep the various parts of the crater are and other information critical to scientific investigations of the Moon.

Another recent view released by the LRO camera team is of impact melt deposit on another unnamed crater on nearside highlands (38.112°N, 53.052°E; northeast of Mare Tranquillitatis). Again, Nathanial Burton-Bradford provides a 3-D view, and amazingly, the crater walls appear deceptively steep in 3-D as opposed to the regular 2-D view:

3d_impact_melt__crater_rim_near_side_by_nathanial_bb-d4yj6l4 — 3D anaglyph of rim impact melt deposit on Unnamed crater on nearside highlands (38.112°N, 53.052°E; northeast of Mare Tranquillitatis). Credit: NASA/GSFC/Arizona State University; anaglyph by Nathanial Burton-Bradford.

What is impact melt? “So much energy is released when an asteroid or comet slams into the Moon that some of target rock (the Moon) is melted,” wrote Lillian Ostrach on the LRCO website. “For large craters, such as Tycho or Copernicus, the impact event responsible for forming these craters was large enough to generate melt that coated and covered the crater floor, and ejected melt pooled and flowed outside the crater cavity.”

Ostrach says that LROC images show that impact melt is widespread and quite common to lunar impact craters — but as this image shows – take a close look to find channels, flows, and veneers across much of the region.

Here’s LROC’s regular view:

M170205366LE_new — Impact melt started to flow back into the crater cavity before it solidified. Image width is 500 m, from the LROC Narrow Angle Camera. Credit: NASA/GSFC/Arizona State University.

Find out more about these recent LRO images on the LROC website, and see more of Nathanial’s photography handiwork at his DeviantArt page.

May 2, 2012December 23, 2015 by Nancy Atkinson

Supermoon This Weekend

A 'side by side' comparison of 4 different shots taken over the period of 30 hours before the March 19, 2011 'SuperMoon'. It shows the progression of Moon in it's orbit until the closest point. Credit: Ramiz Qureshi, from Karachi, Pakistan.

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This weekend will provide the full Moon’s closest approach of the year to Earth. On Saturday, May 5, 2012 the Moon could appear as much as 14% bigger and 30% brighter than other full Moons of 2012, according to some calculations. Will you notice it? Not if you haven’t really been paying attention, or have a reference point to compare it to other full Moons. And it certainly won’t have any adverse effects on Earth, as this closest approach happens every year — just a fact of orbital mechanics. But perhaps a great way to celebrate Cinco de Mayo is to spend the evening gazing at the Moon!

Every month, as the Moon circles the Earth in its elongated orbit, its distance from the Earth varies. This weekend, the Moon is reaching what’s known as its perigee, the closest point to Earth in its orbit. It will be about 356,953 kilometers (221,802 miles) from Earth on Saturday. Apogee — when the Moon is farthest away — varies, but is around 405,000 km (252,000 miles) away.

What is most interesting is that the timing of the perigee and full Moon is really, really close: The full moon occurs at 03:34 UTC on May 6 (11:34 p.m. EDT on May 5 )eastern and perigee follows at 03:35 UTC (11:35 p.m. EDT)

David Morrison, from NASA says “supermoon” is not an astronomical term and he confirms a supermoon has no effect on Earth, and that the change in size is hardly noticeable to the average person. If you miss it, the Moon will be very nearly as close at the next full Moon, and very nearly as close as it was at the last full Moon.

But even better is that two weeks after the “supermoon” on May 5th, the Moon will be at apogee as it lines up in front of the Sun for an amazing annular eclipse on May 20th. An annular eclipse occurs when the Sun and Moon are exactly in line, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or annulus, surrounding the outline of the Moon.

If you’re a photographer, take a picture of the Moon and send it to us. If we get a some good images, we’ll share them. Join our Flickr group, or send us your images by email (this means you’re giving us permission to post them). Please explain a little about it such as when you took it, the equipment you used, etc.

Here’s a video NASA put out about the Supermoon:

April 29, 2012December 23, 2015 by Fraser Cain

Pictures of the Moon

The Moon is one of the most familiar and beautiful objects in the night sky (and daytime too!). Let’s take a look at some beautiful images of the Moon. Of course, since Universe Today is a space and astronomy website, all of these pictures of the Moon were taken by spacecraft, or people on board spacecraft.

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Here’s one of the most important pics of the Moon ever captured. That’s because you can see the whole of the Earth as well. This picture of the Moon is called Earthrise, and it was taken by NASA’s astronauts on board Apollo 8 just after it completed its lunar insertion orbit.

The Moon at its nearest and furthest points of its orbit. Image credit: NASA

The Moon follows an elliptical orbit as it travels around the Earth. At some points in its orbit, the Moon is closer to the Earth than others. This picture of the Moon from NASA’s Galileo spacecraft shows the difference in sizes that the Moon can get.

The Earth and Moon, seen from the shuttle Discovery. Image credit: NASA

This is a picture of the Moon, but it’s also a picture of the Earth, seen from space as well as the space shuttle Discovery. This image of the Moon was captured during a mission in 1998.

Here’s a side of the Moon that very few people have ever seen with their own eyes. This photo of the Moon shows its far side. The image was taken by NASA’s Galileo spacecraft as it was speeding out on its journey to Jupiter.

And finally, this isn’t a photograph, but it’s an artist’s illustration of what might have happened during the formation of the Moon. In this image of the Moon, a Mars-sized object is crashing into the Earth. After this, the spray of debris from the collision orbited the Earth and eventually collected together to form the Moon.

Moon Landing Photos

Moon Landing Pictures — Apollo moon landing sites

For all you conspiracy buffs out there, here’s evidence that the Moon landings really happened. Here are some pictures of the lunar surface taken by NASA’s Lunar Reconnaissance Orbiter showing the location of all the lunar landings. The pictures are so high resolution, you can see the shadows of the lander and even the astronaut footprints.

This is a portrait of astronaut and scientist Harrison H. Schmitt standing beside the US flag on the Moon. While most astronauts were test pilots, Schmitt was an actual geologist. It was incredibly useful to have a scientist studying the lunar rocks and soil, searching for evidence.

This is astronaut Alan Bean standing on the surface of the Moon. He’s holding a special container that has lunar soil in it. This picture was taken in the vicinity of Sharp Crater.

Here’s a classic picture of Buzz Aldrin’s footprint on the Moon; he was the second person to set foot on the Moon. Because there’s no weather on the Moon, this footprint should remain here for millions of years.

This is a photo of Buzz Aldrin climbing down outside the Apollo 11 capsule, becoming the second person to set foot on the surface of the Moon. This picture was taken by Neil Armstrong, the first person on the Moon.

Full Moon Pictures

This is a stunning photo of full moon taken by the astronauts onboard the International Space Station during the Expedition 10 mission. The moon is the only natural satellite of the planet Earth.

This breathtaking photo moon and the earth’s atmosphere was taken from the International Space Station by an Expedition 10 crew member in October 2004. Expedition 10 crew members, Leroy Chiao and Salizhan Sharipov relieved the two Expedition 9 crew members, Mike Fincke and Gennady Padalka.

Here’s another amazing picture of the moon in full view. This image was taken by the Expedition 12 crew members onboard the International Space Station on February 12, 2006.

Full Moon with Earth's Horizon and Airglow Visible at Left

This is an Expedition 14 picture of the full moon taken on December 4, 2006. The moon is the brightest object visible in the earth’s sky after the sun.

Here’s a nice photo of the earth’s moon generated from the 18 images captured by the Galileo spacecraft on December 7, 1992 on its way to Jupiter. The Moon is the only natural satellite of the earth. The moon’s surface, as seen on the image is composed of many impact craters.

New Moon Pictures

Almost New Moon with Venus. Image credit: Voobie

This is an image of the Moon when it was almost a new moon. The bright star in the picture isn’t a star at all but the planet Venus. This photo was taken by Voobie.

This is an image of a double conjunction, where the Moon was close in the sky to two planets, Jupiter and Venus.

New Moon with airplane. Image credit: Stefan Seip

Amateur astronomer Stefan Seip caught this amazing photograph of a passenger airplane passing in front of an almost perfect New Moon.

New moon with Venus. Image credit: James W. Young

Another great image of a new moon. This time the Moon is only 37 hours old. This picture was taken by James W. Young from the Table Mountain Observatory.

April 29, 2012December 23, 2015 by Tammy Plotner

Weekly SkyWatcher’s Forecast: April 30-May 6, 2012

Large Magellanic Cloud - Image Courtesy of NASA

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Greetings, fellow SkyWatchers! Are you ready for another week filled with bright planets, a meteor shower, challenging lunar features, interesting stars and astronomy history? Then you have come to the right place! Bring along your telescopes and binoculars and meet me in the backyard…

Monday, April 30 – Karl Frederich Gauss was born on this day in 1777. Known as the “Prince of Mathematics,” Gauss contributed to the field of astronomy in many ways – from computing asteroid orbits to inventing the heliotrope. Out of Gauss’ many endeavors, he is most recognized for his work in magnetism. We understand the term “gauss” as a magnetic unit – a refrigerator magnet carries about 100 gauss while an average sunspot might go up to 4000. On the most extreme ends of the magnetic scale, the Earth produces about 0.5 gauss at its poles, while a magnetar can produce as much as 10 to the 15th power in gauss units!

While we cannot directly observe a magnetar, those living in the Southern Hemisphere can view a region of the sky where magnetars are known to exist – the Large Magellanic Cloud – or you can use the projection method to view a sunspot! If you have a proper solar filter, magnetism distorts sunspots as they near the limb – called the “Wilson Effect”

Tuesday, May 1 – On this day in 1949 Gerard Kuiper discovered Nereid, a satellite of Neptune. If you’re game, you can find Neptune – usually hanging around in Capricornus – about an hour before dawn. While it can be seen in binoculars as a bluish “star,” it takes around a 6″ telescope and some magnification to resolve its disc. Today’s imaging technology can even reveal its moons!

While you’re out this morning, keep an eye on the sky for the peak of the Phi Bootid meteor shower, whose radiant is near the constellation of Hercules. While the best time to view a meteor shower is around 2:00 a.m. local time, you will have best success watching for these meteors when the Moon is as far west as possible. The average fall rate is about 6 per hour.

Our lunar mission for tonight is to move south, past the crater rings of Ptolemaeus, Alphonsus, Arzachel, and Purbach, until we end up at the spectacular crater Walter.

Named for Dutch astronomer Bernhard Walter, this 132- by 140-kilometer-wide lunar feature offers up amazing details at high power. It is worthwhile to take the time to study the differing levels, which drop to a maximum of 4,130 meters below the surface. Multiple interior strikes abound, but the most fascinating of all is the wall crater Nonius. Spanning 70 kilometers, Nonius would also appear to have a double strike of its own—one that’s 2,990 meters deep!

Wednesday, May 2 – On the lunar surface, we can enjoy a strange, thin feature. If you used last night’s map, you’re well acquainted with this area! Look toward the lunar south where you will note the prominent rings of craters Ptolemaeus, Alphonsus, Arzachel, Purbach, and Walter descending from north to south. Just west of them, you’ll see the emerging Mare Nubium. Between Purbach and Walter you will see the small, bright ring of Thebit with a crater caught on its edge. Look further west and you will see a long, thin, dark feature cutting across the mare. Its name? Rupes Recta – better known as The Straight Wall, or sometimes Rima Birt. It is one of the steepest known lunar slopes rising around 366 meters from the surface at a 41 degree angle.

Be sure to mark your lunar challenge notes and we’ll visit this feature again!

Another great target for a bright night is Delta Corvi. 125 light-years away, it displays a yellowish color primary and slightly blue secondary that’s an easily split star in any telescope, and a nice visual double with Eta in binoculars. Use low power and see if you can frame this bright grouping of stars in the same eyepiece field.

Before you put the telescope away for the evening, be sure to visit with Mars. If you’ve been keeping track, the red planet is slowly moving away from us and dimming even more. Tonight it should have reached an apparent -0.0 magnitude. Compare it to other nearby stars and gauge its brightness for yourself. How has its apparent position against the background stars changed over the weeks? Have you noted features like Syrtis Major or Amazonis Planitia? How have the polar caps changed?

Thursday, May 3 – Tonight we’ll use what we learned previously to locate another unusual feature – Montes Recti or the “Straight Range.” You’ll find this curiosity tucked between Plato and Sinus Iridum on the north shore of Mare Imbrium.

To binoculars or small scopes at low power, this isolated strip of mountains will appear as a white line drawn across the grey mare. It is believed this feature may be all that is left of a crater wall from the Imbrium impact. It runs for a distance of around 90 kilometers, and is approximately 15 kilometers wide. The Straight Range and some of its peaks reach up to 2072 meters! Although this doesn’t sound particularly impressive, that’s over twice as tall as the Vosges Mountains in central western Europe, and on the average very comparable to the Appalachian Mountains in the eastern United States.

Friday, May 4 – Tonight you are on your own without a map. Lunar features are easy when you become acquainted with them! Return to the Moon and explore with binoculars or telescopes the area to the south around another easy and delightful lunar feature you should recognize, the crater Gassendi. At around 110 kilometers in diameter and 2010 meters deep, this ancient crater contains a triple mountain peak in its center. As one of the most “perfect circles” on the Moon, the south wall of Gassendi has been eroded by lava flows over a 48 kilometer expanse and offers a great amount of detail to telescopic observers on its ridge- and rille-covered floor. For those observing with binoculars? Gassendi’s bright ring stands on the north shore of Mare Humorum…an area about the size of the state of Arkansas!

Northeast of Regulus by about a fistwidth is 2.61 magnitude Gamma Leonis – also known as Algieba. This is one of the finest double stars in the sky, but a little difficult at low power since the pair is both bright and close. Separated by about twice the diameter of our own solar system, this 90 light-year distant pair is slowly widening.

Another two fingerwidths north is 3.44 magnitude Zeta Leonis – also named Aldhafera. Located about 130 light-years away, this excellent star has an optical companion which is viewable in binoculars – 35 Leonis. Remember this pair, because it will lead you to galaxies later!

Saturday, May 5 – In 1961 Alan Shepard became the first American in “space” (as we now refer to that region above the sky), taking a 15 minute suborbital ride aboard the Mercury craft Freedom 7.

Return to the Moon tonight to have a look on the terminator near the southern cusp for two outstanding features. The easiest is crater Schickard – a class V mountain-walled plain that spans 227 kilometers. Named for German astronomer Wilhelm Schickard, this beautiful old crater with the subtle interior details has another crater caught on its northern wall named Lehmann.

Look further south for one of the Moon’s most incredible features – Wargentin. Among the many strange things on the lunar surface, Wargentin is unique. Once upon a time, it was a very normal crater and had been that way for hundreds of millions of years – then it happened. Either a fissure opened in its interior, or the meteoric impact that formed it caused molten lava to begin to rise. Oddly enough, Wargentin’s walls were without large enough breaks to allow the lava to escape and it continued to fill the crater to the rim. Often referred to as “the Cheese,” enjoy Wargentin tonight for its unusual appearance and be sure to note Nasmyth and Phocylides as well!

Before we leave, let’s have a look east at 3.34 magnitude Theta Leonis. Also known as Chort, mark this one in your memory, as well as 3.94 magnitude Iota to the south as markers for a galaxy hop. Last is easternmost 2.14 magnitude Beta. Denebola is the “Lion’s Tail” and has several faint optical companions.

Sunday, May 6 – Earlier we learned about awesome magnetic energy, but what happens when you find magnetism in a very unlikely place? Tonight might be Full Moon, but we can still have a look at the lunar surface just a little southeast of the grey oval of Grimaldi. The area we are looking for is called the Sirsalis Rille and on an orb devoid of magnetic fields – it’s magnetic! Like a dry river bed, this ancient “crack” on the surface runs 480 kilometers along the surface and branches in many areas.

For those who like curiosities, our target for tonight will be 1.4 degrees northwest of 59 Leonis, which is itself about a degree southwest of Xi. While this type of observation may not be for everyone, what we are looking for is a very special star – a red dwarf named Wolf 359 (RA 10 56 28.99 Dec +07 00 52.0).

Discovered photographically by Max Wolf in 1959, charts from that time period will no longer be accurate because of the star’s large proper motion. It is one of the least luminous stars known, and we probably wouldn’t even know it was there except for the fact that it is the third closest star to our solar system. Located only 7.5 light-years away, this miniature star is about 8% the size of our Sun – making it roughly the size of Jupiter. Oddly enough, it is also a “flare star” – capable of jumping another magnitude brighter at random intervals. It might be faint and difficult to spot in mid-sized scopes, but Wolf 359 is definitely one of the most unusual things you will ever observe!

Until next week? Ask for the Moon, but keep on reaching for the stars!

April 25, 2012December 23, 2015 by Nancy Atkinson

Ancient Asteroids Kept Pelting Earth in a ‘Late-Late’ Heavy Bombardment

This is an artist’s depiction of a 10-kilometer (6-mile) diameter asteroid striking the Earth. New evidence in Australia suggests an asteroid 2 to 3 times larger than this struck Earth early in its life. Credit: Don Davis/Southwest Research Institute.

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Even though the Late Heavy Bombardment is somewhat of a controversial idea, new research has revealed this period of impacts to the Earth-Moon system may have lasted much longer than originally estimated and well into the time when early life was forming on Earth. Additionally, this “late-late” period of impacts — 3.8 billion to 2.5 billion years ago — was not for the faint of heart. Various blasts may have rivaled those that produced some of the largest craters on the Moon, and could have been larger than the dinosaur-killing impact that created the Chicxulub crater 65 million years ago.

“Our work provides a rationale that the last big impacts hit over an extended time,” said William Bottke principal investigator of the impact study team at the NASA Lunar Science Institute’s Center of Lunar Origin and Evolution (CLOE), based at the Southwest Research Institute (SwRI) in Boulder, Colorado.

The evidence for these prodigious impacts comes from bead-like impact ‘spherules’ found in millimeter- to centimeter-thick rock layers on Earth and date from the Archean period of Earth’s history, more recent than the estimated LHB period of 4.1 to 3.8 billion years ago.

“The beds speak to an intense period of bombardment of Earth,” Bottke said. “Their source long has been a mystery.”

The circles seen in the image above are all formerly molten droplets ejected into space when an asteroid struck the Earth about 2.56 billion years ago. The droplets returned to Earth and were concentrated at the base of the Reivilo layer in South Africa.

The spherules still contain substantial extraterrestrial material, such as iridium (176 parts per million), which rules out alternative sources for the spherules, such as volcanoes, according to Bruce Simonson, a geologist from the Oberlin College and Conservatory who has studied these ancient layers for decades.

The timing of these impacts also coincides with a record of large lunar craters being created more recently than 3.8-billion years ago.

At least 12 spherule beds deposited between 3.47 and 1.7 billion years ago have been found in protected areas on Earth, such as in shales deposited on the seafloor below the reach of waves.

From these beds, the team found evidence of approximately 70 impacts on Earth during this time period that were likely larger than the Chicxulub impact.

In their paper, which was published in Nature, the team created a computer model of the ancient main asteroid belt and tracked what would have happened when the orbits of the giant planets changed. They extended the work of the Nice Model, which supports the theory that Jupiter, Saturn, Uranus and Neptune formed in different orbits nearly 4.5 billion years ago and migrated to their current orbits about 4 billion years ago, triggering a solar system-wide bombardment of comets and asteroids called known as the LHB.

postlc-solar-system — This image shows a representation of how the giant planets have migrated to the current orbits, destabilizing the extension of the primordial asteroid belt closest to Mars. This drove numerous big impactors onto orbits where they could hit the terrestrial planets, though over a long enough time span that this drawn-out barrage may have lasted more than a billion years. The frequency of these impacts on Earth was enough to reproduce the known impact spherule beds. Image Courtesy David Kring, Center for Lunar Science and Exploration, and the Lunar and Planetary Institute

The new computer model shows that the innermost portion of the asteroid belt could have become destabilized, delivering numerous big impacts to Earth and Moon over longer time periods.

Have there been any previous indications about this period of impacts?

“The problem is that we have almost no Archean rocks,” Bottke told Universe Today. “The oldest terrestrial craters, Sudbury and Vredefort, are 1.85 and 2.02 billion years old. The spherule beds are our only window into impacts prior to this time.”

Also, Bottke said, the number of people who look for impact spherules is almost equally scarce. “People such as Bruce Simonson, Don Lowe, Gary Byerly, and Frank Kyte, have been carrying on a long, lonely quest to try to get people to consider the implications of their work, which are deeply profound, in my opinion,” Bottke said.

As for finding evidence of this later period of impacts on the Moon, Bottke said the problem there is the lack of solid ages for most impact events.

“This means it is difficult say anything definitive about the timing of major impacts,” Bottke said. “We are working this problem now with Michelle Kirchoff, who is counting craters on top of large lunar craters. This can be done now that we have LRO data.” (Listen to a podcast interview of Kirchoff on the 365 Days of Astronomy.)

Still, Bottke said, without using “fancy dynamics,” they can address some issues.

“Studies in the post-Apollo era suggested that the Moon has four 160-300 km craters that formed after Orientale, whose age is 3.7-3.8 billion years ago and (i.e., K/T-sized events or larger),” he said. “Crater counts from the Galileo mission and Apollo-era geologic analyses suggest at least one of these events took place near 3.2-3.5 billion years ago. If we account for the gravitational cross section of the planets, we know that for every lunar event, we should get about 20 on the Earth. So, from this argument alone, one should get a lot of big impacts on the Earth after the formation of Orientale.”

The new study fits with the available constraints about impacts on the Moon as well as finding the right distribution of spherule beds on Earth.

The best way to confirm everything, however, Bottke said, would be if more lunar rocks from various locations were available for study.

Read the team’s paper in Nature.

Further reading:
Press release from SwRI.
NLSI press release

April 24, 2012December 23, 2015 by Jason Major

Lunar Satellite Reveals Apollo 16 Remains

LROC image of the Apollo 16 site showing the Orion LM. (NASA/GSFC/Arizona State University)

NASA’s Lunar Reconnaissance Orbiter (LRO) made a low pass over the Apollo 16 site last fall, capturing images of the leftovers from John Young and Charlie Duke’s 1972 exploration of the Descartes Highlands. The video above takes us on a tour of the Apollo 16 site from lunar orbit, and includes audio from the original communications and some very nice comparative photos and video clips showing the same features from ground level.

The goal of Apollo 16 was to explore for the first time a lunar highlands location, and collect samples of what were initially thought to be volcanic rocks. The rocks were believed to be of a different material than what was collected during previous missions.

As it turned out, the rocks collected by Duke and Young weren’t volcanic in origin at all; they ended up being breccias — cemented-together chunks ejected from ancient cratering events hundreds of miles away.

Apollo 16 also set up various experiment packages to study lunar geology, magnetism and the solar wind. The Lunar Roving Vehicle (LRV) allowed Young and Duke to travel across a much wider area than they would have otherwise been able to on foot. It was the second mission to use an LRV, and the rover — as well as its tracks — are still there today, looking exactly as they did when they were left 40 years ago.

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The Apollo 16 ascent stage lifted off from the lunar surface on the evening of April 23, 1972 and docked with the Command Module containing Ken Mattingly. The following day the astronauts began their trip back to Earth, completing the 250,000-mile traverse three days later on April 27.

The Moon would be visited again in December of that same year during Apollo 17, the last mission of the program and the last time that humans would walk on the surface of another world. Now, 40 years later, satellites orbiting the Moon take pictures of what was left behind by these historic events. Perhaps someday soon the sites will be visited from ground level… maybe even by a new generation of astronauts.

Apollo16_pan — Panorama of the Descartes Highlands site made from 3 Hasselblad film image scans combined together. (NASA/JSC/J. Major)

Read more about this on Arizona State University’s LROC site, and explore the full-frame Narrow-Angle Camera image from the LROC here.

Video: NASA/GSFC/Arizona State University

April 24, 2012December 23, 2015 by Jason Major

The Family that Went to the Moon

A picture of a photograph: the family photo that Charlie Duke left on the Moon on April 23, 1972. (NASA)

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Well, the family photo, anyway.

On April 23, 1972, Apollo 16 astronauts Charlie Duke and John Young embarked on the third and final EVA of the mission, exploring the Descartes Highlands via Lunar Roving Vehicle. During the EVA, before setting up a Solar Wind Collector, Duke placed a small family photo he had brought along onto the lunar surface and snapped a few photos of it with his Hasselblad film camera. This is one of the photos.

The portrait shows Charlie, his wife Dorothy, and their two sons Charles and Thomas. It looks like they are sitting on a bench in the summertime.

The family photo, gingerly wrapped in clear plastic and slightly crumpled from being stashed in the pocket of a space suit, was left on the Moon. It presumably still sits there today, just inches away from Charlie’s boot print — which, presumably, is also there.

At the time of this writing it’s been exactly 40 years to the day that this photo was taken.

Image: NASA/JSC scan

I came across this image while looking through the Project Apollo Image Archive for some relevant images from the Apollo 16 mission. Amid scans of Hasselblad photos showing lunar samples, experiments and scenes from LRV jaunts, which are all fascinating in their own right, I came across this poignant image and couldn’t resist sharing it. To know that a family photo is resting upon the surface of another world is nothing short of amazing… while the missions to the Moon were a testament to human endeavor, it’s small things like this that remind us of the people that made it all possible.

April 23, 2012December 23, 2015 by Nancy Atkinson

Join the Million Crater Challenge

Like a challenge? Right now you can join in a contest to mark a million craters, as part of the Moon Mappers project. “Our challenge to you is to try and observe 1 million craters on the Moon before the full Moon again rises in the evening sky on May 5,” said Dr. Pamela Gay, who leads the Cosmoquest program of citizen science project. “Help us ‘illuminate’ the Moon with new scientific discoveries one crater at a time.”

As an enticement to join in, there are prizes!

There will be prizes for the ten CosmoQuest community members who make the observations closest to each interval of 100,000, and for 10 additional randomly selected community members who participate in this challenge. Prizes include Surly Amy pendants, Astrosphere posters, and Lunar Reconnaissance Orbiter lithographs.

Are there a million craters on the Moon? Dr. Gay said that with LRO, craters the size on 1 meter can be seen. But for Moon Mappers, participants are asked to identify craters nine meters in diameter. “There are literally millions of craters at that size,” she said.

Moon Mappers is not only fun, but your contributions help build a new scientific understanding of the Moon. The Moon Mappers team has already published their first scientific paper based on the work done by citizen scientists, so help them keep going to discover as much as we can about the Moon.

Check out Moon Mappers!

April 23, 2012December 23, 2015 by Jason Major

Earthrise, Revisited

The first color photo of Earth taken from orbit around the Moon. (NASA)

On December 24, 1968, Apollo 8 astronauts Frank Borman, William Anders and Jim Lovell were the first humans to witness an Earthrise as our home planet came up over the lunar horizon. The photos they captured were the first of their kind, instantly inspiring the imaginations of millions and highlighting the beauty and fragility of our world.

Now, NASA has used modern satellite data to recreate the scenes that the Apollo 8 astronauts saw 44 years ago and combined them with their historic photographs to present a new “Earthrise”… version 2.0.

Created in recognition of Earth Day 2012, the Earthrise animation was made from data acquired by NASA’s Lunar Reconnaissance Orbiter’s laser altimeter, as well as the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra Earth-observing satellite.

“This visualization recreates for everyone the wondrous experience of seeing Earth from that privileged viewpoint,” says LRO Project Scientist Rich Vondrak of NASA’s Goddard Space Flight Center.

Animator Ernie Wright recreated the scene using Apollo mission reports and photos taken by the crew. The audio is a recording of original communication from the astronauts.

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“I think the one overwhelming emotion that we had was when we saw the earth rising in the distance over the lunar landscape… it makes us realize that we all do exist on one small globe. For from 230,000 miles away it really is a small planet.”

— Frank Borman, Apollo 8 Commander

Read the release on the NASA LRO site here.

Video: NASA/GSFC