Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: April 23-29, 2012

Mars In Leo - Credit: John Chumack

[/caption]

Greetings, fellow SkyWatchers! What a great week to just enjoy some great unaided eye astronomy observations. Who can resist the beautiful appearance of Mars in Leo? Also this week, you’ll enjoy not one – but two – meteor showers as the Mu Virginids come to town mid-week and the Bootids light up the weekend. Get ready to enjoy bright stars, find planets, explore lunar features, learn some astronomy history and much more! When ever you’re ready, meet me in the back yard…

Monday, April 23 – Pioneer quantum physicist Max Planck was born on this day in 1858. In 1900, Max developed the Planck equation to explain the shape of blackbody spectra (a function of temperature and wavelength of emission). A “blackbody” is any object that absorbs all incident radiation – regardless of wavelength. For example, heated metal has blackbody properties because the energy it radiates is thermal. The blackbody spectrum’s shape remains constant, and the peak and height of an emitter can be measured against it – be it cosmic background radiation – or our own bodies.

Now, let’s put this knowledge into action. Stars themselves approximate blackbody radiators, because their temperature directly controls the color we see. A prime example of a “hot” star is Alpha Virginis, better known as Spica. Compare its color to the cooler Arcturus… What colors do you see? There are other astronomical delights that radiate like blackbodies over some or all parts of the spectrum as well. You can observe a prime example in a nebula such as M42, in Orion. By examining the radio portion of the spectrum, we find the temperature properly matches that of electrons involved in the process of fluorescence. Much like a common household fixture, this process is what produces the visible light we can see.

Tuesday, April 24 – Today in 1970, China launched its first satellite. Named Shi Jian 1, it was a successful technological and research craft. This achievement made China the fifth country to send a vessel into space.

Tonight see if you can spot the tender beginnings of the Moon after sunset. Observers take pleasure in sweeping the sky with small scopes and binoculars in hopes of finding the thinnest possible lunar crescent. And speaking of crescents, did you spot Venus close to the Moon? Why not take out your telescope and see what phase Venus is now in. If you don’t have a filter to cut its bright glare, try wearing sunglasses!

No telescope? No problem. You can still do some very awesome astronomy with just your eyes! Begin with locating the northern constellation of Ursa Major – most commonly known as the “Big Dipper”. Take note of the curve of the Dipper’s “handle” and trace it from the bottom of the cup and continue on the “Arc to Arcturus”. Keep moving, because now you’re going to “Speed on to Spica”! Once you’ve located this bright, blue/white star, simply look to its east/southeast (or upper left) for a yellow appearing “star”. That’s no star… That’s Saturn!

Now let’s have a look at 140 light-year distant Epsilon Hydrae – the northernmost star in the small circlet east of Procyon. While it and Rho will make a beautiful visual double for binoculars, Epsilon itself is a multiple system. Its A and B components are a tough split for any scope, but the 8th magnitude C star is easier. The D component is a dwarf star.

Wednesday, April 25 – Today marks the 15th anniversary of the deployment of Hubble Space Telescope. While everyone in the astronomical community is well aware of what this magnificent telescope “sees,” did you know that you can see it with just your eyes? The HST is a satellite that can be tracked and observed. Visit heavens-above.com and enter your location. This page will provide you with a list of visible passes for your area. Although you can’t see details of the scope itself, it’s great fun to track with binoculars or see the Sun glinting off its surface in a scope.

Tonight our first voyage is to the Moon’s surface. Look along the terminator in the southern quadrant and revisit ancient old crater Furnerius. Named for French Jesuit mathematician George Furner, this crater spans approximately 125 kilometers and is a lunar club challenge. Power up and look for two interior craters. The smaller is crater A and it spans a little less than 15 kilometers and drops to a depth of over 1000 meters. The larger crater C is about 20 kilometers in diameter, but goes far deeper, to more than 1400 meters. That’s about as deep as a coral will grow under the Earth’s oceans!

Keep a watch on the skies while you’re out as the Mu Virginid meteor shower reaches its peak at 7 to 10 per hour. With dark skies tonight, you still might catch one of these medium speed meteors radiating from a point near the constellation of Libra.

Thursday, April 26 – On this date in 1920, the Shapely-Curtis debate raged in Washington on the nature of and distance to spiral nebulae. Shapely claimed they were part of one huge galaxy to which we all belonged, while Curtis maintained they were distant galaxies of their own. Thirteen years later on the same date, Arno Penzias was born. He went on to become a Nobel Prize winner for his part in the discovery of the cosmic microwave background radiation, through searching for the source of the “noise” coming from a simple horn antenna. His discovery helped further our understanding of cosmology in ways that Shapely and Curtis could have never dreamed of.

Perhaps they dreamed of Moon? We’ve got Moon! No matter, what we really want to do is revisit and study a changeable, sometimes transient, and eventually bright feature on the lunar surface – crater Proclus. At around 28 kilometers in diameter and 2400 meters deep, Proclus will appear on the terminator on the west mountainous border of Mare Crisium. For many viewers tonight, it will seem to be about 2/3 black, but 1/3 of the exposed crater will be exceptionally brilliant – and with good reason. Proclus has an albedo, or surface reflectivity, of about 16%, which is an unusually high value for a lunar feature. Watch this area over the next few nights as two rays from the crater will widen and lengthen, extending approximately 322 kilometers to both the north and south. Congratulations on another lunar club challenge!

Friday, April 27 – Tonight we’re heading towards the lunar surface to view a very fine old crater on the northwest shore of Mare Nectaris – Theophilus. Slightly south of mid-point on the terminator, this crater contains an unusually large multiple-peaked central mountain which can be spotted in binoculars. Theophilus is an odd crater, one that is a parabola – with no area on the floor being flat. It stretches across a distance of 100 kilometers and dives down 440 meters below the surface. Tonight it will appear dark, shadowed by its massive west wall, but look for sunrise on its 1400 meter summit!

Now, let’s try picking up a globular cluster in Hydra that is located about 3 fingerwidths southeast of Beta Corvus and just a breath northeast of double star A8612 – M68 (Right Ascension:12 : 39.5 – Declination: -26 : 45). This class X globular was discovered in 1780 by Charles Messier and first resolved into individual stars by William Herschel in 1786. At a distance of approximately 33,000 light-years, it contains at least 2000 stars, including 250 giants and 42 variables. It will show as a faint, round glow in binoculars, and small telescopes will perceive individual members. Large telescopes will fully resolve this small globular to the core!

While you’re out, have a look at 27 Hydrae about a fingerwidth southwest of Alpha. It’s an easy double for any equipment with its slightly yellow 5th magnitude primary and distant, white, 7th magnitude secondary. Although it is wide, the pair is a true binary system.

Saturday, April 28 – Today was a very busy day in astronomy history. Newton published his Principia in 1686 on April 28. In 1774, Francis Baily was born. He went on to revise star catalogs and explain the phenomenon at the beginning and ending of a total solar eclipse which we know as “Baily’s Beads.” 1900 saw the birth of Jan Hendrick Oort, who quantified the Milky Way’s rotation characteristics and envisioned the vast, spherical area of comets outside our solar system that we now call the Oort Cloud. Last, but not least, was the birth of Bart Jan Bok in 1906 who studied the structure and dynamics of the Milky Way.

Tonight’s outstanding lunar feature will be crater Maurolycus just southwest of the three rings of Theophilus, Cyrillus and Catharina. This lunar club challenge spans 114 kilometers and goes below the lunar surface by 4730 meters. Be sure to look for Gemma Frisius just to its north.

Now let’s check out a dandy little group of stars that are about a fistwidth southeast of Procyon and just slightly more than a fingerwidth northeast of M48. Called C Hydrae, this group isn’t truly gravitationally bound, but is a real pleasure to large binoculars and telescopes of all sizes. While they share similar spectral types, this mixed magnitude collection will be sure to delight you!

For SkyWatchers, no equipment is necessary to enjoy the Alpha Bootid meteor shower – despite the Moon. Pull up a comfortable seat and face orange Arcturus as it climbs the sky in the east. These slow meteors have a fall rate of 6 to 10 per hour and leave very fine trails, making an evening of quiet contemplation most enjoyable.

Sunday, April 29 – Before we explore space, let’s have a look at the Moon and the close apparition of Regulus and Mars! The three make a wonderful “line up” the night sky! Now, let’s start our lunar observations tonight as challenge craters Cassini and Cassini A come into view just south of the black slash of the Alpine Valley. The major crater spans 57 kilometers and reaches a floor depth of 1240 meters. The challenge is to also spot the central crater A, which is only 17 kilometers wide, yet drops down another 2830 meters below the surface.

While we’re out, have a look at R Hydrae about a fingerwidth east of Gamma – which is a little more than fistwidth south of Spica. R is a beautiful, red, long-term variable first observed by Hevelius in 1662. Located about 325 light-years from us, it’s approaching – but not that fast. Be sure to look for a visual companion star as well!

Until next week? Dreams really do come true when you keep on reaching for the stars!

Many thanks to John Chumack of Galactic Images for his outstanding photo of “Leo In Mars”!

Posted on by Jason Major

Scientists Suggest Evidence of Recent Lunar Volcanism

There may be a volcanic vent on the central peak of Tycho crater, according to an Indian research team. (Image: NASA Goddard/Arizona State University)

[/caption]

A team of researchers at India’s Physical Research Laboratory (PRL) claims it has found evidence of relatively recent volcanic activity on the Moon, using data from NASA’s Lunar Reconnaissance Orbiter and the Chadrayaan-1 spacecraft. According to the findings the central peak of Tycho crater contains features that are volcanic in origin, indicating that the Moon was geologically active during the crater’s formation 110 million years ago.

In an article by the Deccan Herald, a Bangalore-based  publication, the PRL researchers claim that vents, lava channels and solidified flows of inner crustal material found within Tycho were made as recently as 100 million years ago — after the creation of the crater.

This could indicate that there was pre-existing volcanic activity within the Moon at the site of the Tycho impact, lending credence to the idea that the Moon was recently geologically active.

In addition, large boulders ranging in size from 33 meters to hundreds of yards across have been spotted on Tycho’s central peaks by LRO, including one 400-foot (120-meter) -wide specimen nestled atop the highest summit. How did such large boulders get there and what are they made of?

A 400-foot-wide boulder within the central peak of Tycho. (NASA/GSFC/LROC)

The researchers hint that they may also be volcanic in origin.

“A surprise findings revealed the  presence of large boulders–about 100 meter in size –on top of the peak. Nobody knew how did they reach the top,” said Prakash Chauhan, a PRL scientist.

Without further studies it’s difficult to determine the exact origin and ages of these lunar formations. The team awaits future research by Chandrayaan-II, which will examine the Moon from orbit as well as land a rover onto the lunar surface. Chandrayaan-II is expected to launch in early 2014.

The PRL team’s findings were published in the April 10 issue of Current Science.

Read the article in the Deccan Herald here.

Posted on by Jason Major

What’s the Moon Made Of? Earth, Most Likely.

continents
An impact between a Mars-sized protoplanet and early Earth is the most widely-accepted origin of the Moon. Did smaller impacts seed the formation of continents? (NASA/JPL-Caltech)

[/caption]

Recent research on lunar samples has shown that the Moon may be made of more Earth than green cheese — if by “green cheese” you mean the protoplanet impactor that was instrumental in its creation.

It’s an accepted hypothesis that Earth’s moon was created during an ancient, violet collision between our infant planet and a Mars-sized world called Theia, an event that destroyed Theia and sent part of Earth’s crust and upper mantle into orbit as a brief-lived ring of molten material. This material eventually coalesced to form the Moon, and over the next 4.5 billion years it cooled, became tidally locked with Earth, accumulated countless craters and gradually drifted out to the respectable distance at which we see it today.

Theia’s remains were once assumed to have been a major contributor to the material that eventually formed the Moon.   Lunar samples, however, showed that the ratio of oxygen isotopes on the Moon compared to Earth were too similar to account for such a formation. Now, further research by a team led by scientists from The University of Chicago shows that titanium isotopes — an element much more refractive than oxygen — are surprisingly similar between the Moon and Earth, further indicating a common origin.

“After correcting for secondary effects associated with cosmic-ray exposure at the lunar surface using samarium and gadolinium isotope systematics, we find that the 50Ti/47Ti ratio of the Moon is identical to that of the Earth within about four parts per million, which is only 1/150 of the isotopic range documented in meteorites,” wrote University of Chicago geophysicist Junjun Zhang, lead author of the paper published in the journal Nature Geoscience on March 25.

If the Moon is more Earth than Theia, then what happened to the original impacting body? Perhaps it was made of heavier stuff that sunk deeper into the Moon, or was assimilated into Earth’s mantle, or got lost to space… only more research will tell.

But for now, you can be fairly sure that when you’re looking up at the Moon you’re seeing a piece of Earth, the cratered remnants of a collision that took place billions of years ago.

See the team’s paper here.

Image credit: NASA / JPL-Caltech

Posted on by Nancy Atkinson

Astrophotos: A Colorful Moon

An unusual false color view of our Moon. Credit: César Cantú

[/caption]

Recognize this? Yes, it is our own Moon, but using Photoshop, the photographer, César Cantú from the Chilidog Observatory in Monterrey, Mexico extracted the Moon’s colors and exaggerated them just a bit. “Although exaggerated, the color components are the real highlights,” César said, “with blue indicating a significant amount of titanium, and the orange areas with little iron or titanium. These colorful images are more easy to perform That thanks to digital cameras that detect colors — where with analog cameras, it is still impossible.”

César took the image on April 6, 2012. See his website for more details.

Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Posted on by Ken Kremer

1st Student Selected MoonKAM Pictures Look Inspiringly Home to Earth

Student-run MoonKAM Imager Looks Homeward. This image of the far side of the lunar surface, with Earth in the background, was taken by the MoonKAM system board the Ebb spacecraft as part of the first image set taken from lunar orbit from March 15 – 18, 2012. A little more than half-way up and on the left side of the image is the crater De Forest. Due to its proximity to the southern pole, DeForest receives sunlight at an oblique angle when it is on the illuminated half of the Moon. NASA/Caltech-JPL/MIT/SRS

[/caption]

The first student selected photos of the Moon’s surface snapped by NASA’s new pair of student named Lunar Mapping orbiters – Ebb & Flow – have just been beamed back and show an eerie view looking back to the Home Planet – and all of Humanity – barely rising above the pockmarked terrain of the mysterious far side of our nearest neighbor in space.

Congratulations to Americas’ Youth on an outstanding and inspiring choice !!

The student photo is reminiscent of one of the iconic images of Space Exploration – the first full view of the Earth from the Moon taken by NASA’s Lunar Orbiter 1 back in August 1966 (see below).

The images were taken in the past few days by the MoonKAM camera system aboard NASA’s twin GRAIL spacecraft currently circling overhead in polar lunar orbit, and previously known as GRAIL A and B. The formation-flying probes are soaring over the Moon’s north and south poles.

The nearly identical ships were rechristened as Ebb and Flow after Fourth grade students from the Emily Dickinson Elementary School in Bozeman, Mont., won the honor to rename both spacecraft by submitting the winning entries in a nationwide essay competition sponsored by NASA.

“The Bozeman 4th graders had the opportunity to target the first images soon after our science operations began,” said Maria Zuber, GRAIL principal investigator of the Massachusetts Institute of Technology in Cambridge, Mass., to Universe Today.

“It is impossible to overstate how thrilled and excited we are !”

The initial packet of some 66 student-requested digital images from the Bozeman kids were taken by the Ebb spacecraft from March 15-17 and downlinked to Earth March 20. They sure have lots of exciting classwork ahead analyzing all those lunar features !

“GRAIL’s science mapping phase officially began on March 6 and we are collecting science data,” Zuber stated.

Far Side of Moon Imaged by MoonKAM
This image of the lunar surface was taken by the MoonKAM system onboard NASA’s Ebb spacecraft on March 15, 2012. The 42.3-mile-wide (68-kilometer-wide) crater in the middle of the image (with the smaller crater inside) is Poinsot. Crater Poinsot, named for the French mathematician Louis Poinsot, is located on the northern part of the moon's far side. The target was selected by 4th grade students at Emily Dickinson Elementary School in Montana who had the honor of choosing the first MoonKAM images after winning a nationwide contest. NASA/Caltech-JPL/MIT/SRS

GRAIL’s science goal is to map our Moon’s gravity field to the highest precision ever. This will help deduce the deep interior composition, formation and evolution of the Moon and other rocky bodies such as Earth and also determine the nature of the Moon’s hidden core.

Engaging students and the public in science and space exploration plays a premier role in the GRAIL project. GRAIL is NASA’s first planetary mission to carry instruments – in the form of cameras – fully dedicated to education and public outreach.

Over 2,700 schools in 52 countries have signed up to participate in MoonKAM.

Ebb and Flow - New Names for the GRAIL Twins in Lunar Orbit
4th Grade Students from Bozeman, Montana (inset) won NASA’s contest to rename the GRAIL A and GRAIL B spacecraft and also chose the first lunar targets to be photographed by the onboard MoonKAM camera system. Artist concept of twin GRAIL spacecraft flying in tandem orbits around the Moon to measure its gravity field Credit: NASA/JPL -M ontage: Ken Kremer

5th to 8th grade students can send suggestions for lunar surface targets to the GRAIL MoonKAM Mission Operations Center at UC San Diego, Calif. Students will use the images to study lunar features such as craters, highlands, and maria while also learning about future landing sites.

NASA calls MoonKAM – “The Universe’s First Student-Run Planetary Camera”. MoonKAM means Moon Knowledge Acquired by Middle school students.

The MoonKAM project is managed by Dr Sally Ride, America’s first female astronaut.

“What might seem like just a cool activity for these kids may very well have a profound impact on their futures,” Ride said in a NASA statement. “The students really are excited about MoonKAM, and that translates into an excitement about science and engineering.”

“MoonKAM is based on the premise that if your average picture is worth a thousand words, then a picture from lunar orbit may be worth a classroom full of engineering and science degrees,” says Zuber. “Through MoonKAM, we have an opportunity to reach out to the next generation of scientists and engineers. It is great to see things off to such a positive start.”

MoonKAM image from NASA’s Ebb Lunar Mapping orbiter. This lunar target was selected by the 4th graders at Emily Dickinson Elementary School in Montana who won the contest to rename the GRAIL probes in a nationwide essay contest. NASA/Caltech-JPL/MIT/SRS

Altogether there are eight MoonKAM cameras aboard Ebb and Flow – one 50 mm lens and three 6 mm lenses. Each probe is the size of a washing machine and measures just over 3 feet in diameter and height.

Snapping the first images was delayed a few days by the recent series of powerful solar storms.

“Due to the extraordinary intensity of the storms we took the precaution of turning off the MoonKAMs until the solar flux dissipates a bit,” Zuber told me.

“GRAIL weathered the storm well. The spacecraft and instrument are healthy and we are continuing to collect science data.”

The washing-machine sized probes have been flying in tandem around the Moon since entering lunar orbit in back to back maneuvers over the New Year’s weekend. Engineers spent the past two months navigating the spaceship duo into lower, near-polar and near-circular orbits with an average altitude of 34 miles (55 kilometers) that are optimized for science data collection and simultaneously checking out the spacecraft systems.

Ebb and Flow were launched to the Moon on September 10, 2011 aboard a Delta II rocket from Cape Canaveral, Florida and took a circuitous 3.5 month low energy path to the moon to minimize the overall costs.

The Apollo astronauts reached the Moon in just 3 days. NASA’s next generation Orion space capsule currently under development will send American astronauts back to lunar orbit by 2021 or sooner.

NASA has just granted an extension to the GRAIL mission. Watch for my follow-up report detailing the expanded science goals of GRAIL’s extended lunar journey.

One of the first two remote images of Earth taken from the distance of the Moon on August 23, 1966 by NASA’s Lunar Orbiter 1 spacecraft. Credit: NASA

…….

March 24 (Sat): Free Lecture by Ken Kremer at the New Jersey Astronomical Association, Voorhees State Park, NJ at 830 PM. Topic: Atlantis, the End of Americas Shuttle Program, Orion, SpaceX, CST-100, Moon and the Future of NASA Human & Robotic Spaceflight

Posted on by Ken Kremer

Orion Crew Capsule Targeted for 2014 Leap to High Orbit

The Orion Exploration Flight Test-1 (EFT-1) is scheduled to launch the first unmanned Orion crew cabin into a high altitude Earth orbit in 2014 atop a Delta 4 Heavy rocket from Cape Canaveral, Florida. Artist’s concept. Credit: NASA

[/caption]

NASA is on course to make the highest leap in human spaceflight in nearly 4 decades when an unmanned Orion crew capsule blasts off from Cape Canaveral, Fla., on a high stakes, high altitude test flight in early 2014.

A new narrated animation (see below) released by NASA depicts the planned 2014 launch of the Orion spacecraft on the Exploration Flight Test-1 (EFT-1) mission to the highest altitude orbit reached by a spaceship intended for humans since the Apollo Moon landing Era.

Orion is NASA’s next generation human rated spacecraft and designed for missions to again take humans to destinations beyond low Earth orbit- to the Moon, Mars, Asteroids and Beyond to deep space.


Orion Video Caption – Orion: Exploration Flight Test-1 Animation (with narration by Jay Estes). This animation depicts the proposed test flight of the Orion spacecraft in 2014. Narration by Jay Estes, Deputy for flight test integration in the Orion program.

Lockheed Martin Space Systems is making steady progress constructing the Orion crew cabin that will launch atop a Delta 4 Heavy booster rocket on a two orbit test flight to an altitude of more than 3,600 miles and test the majority of Orion’s vital vehicle systems.

The capsule will then separate from the upper stage, re-enter Earth’s atmosphere at a speed exceeding 20,000 MPH, deploy a trio of huge parachutes and splashdown in the Pacific Ocean off the west coast of California.

Lockheed Martin is responsible for conducting the critical EFT-1 flight under contract to NASA.

Orion will reach an altitude 15 times higher than the International Space Station (ISS) circling in low orbit some 250 miles above Earth and provide highly valuable in-flight engineering data that will be crucial for continued development of the spaceship.

Orion Exploration Flight Test One Overview. Credit: NASA

“This flight test is a challenge. It will be difficult. We have a lot of confidence in our design, but we are certain that we will find out things we do not know,” said NASA’s Orion Program Manager Mark Geyer.

“Having the opportunity to do that early in our development is invaluable, because it will allow us to make adjustments now and address them much more efficiently than if we find changes are needed later. Our measure of success for this test will be in how we apply all of those lessons as we move forward.”

Lockheed Martin is nearing completion of the initial assembly of the Orion EFT-1 capsule at NASA’s historic Michoud Assembly Facility (MAF) in New Orleans, which for three decades built all of the huge External Fuel Tanks for the NASA’s Space Shuttle program.

In May, the Orion will be shipped to the Kennedy Space Center in Florida for final assembly and eventual integration atop the Delta 4 Heavy rocket booster and launch from Space Launch Complex 37 at nearby Cape Canaveral. The Delta 4 is built by United Launch Alliance.

The first integrated launch of an uncrewed Orion is scheduled for 2017 on the first flight of NASA’s new heavy lift rocket, the SLS or Space Launch System that will replace the now retired Space Shuttle orbiters

Continued progress on Orion, the SLS and all other NASA programs – manned and unmanned – is fully dependent on the funding level of NASA’s budget which has been significantly slashed by political leaders of both parties in Washington, DC in recent years.

…….

March 24 (Sat): Free Lecture by Ken Kremer at the New Jersey Astronomical Association, Voorhees State Park, NJ at 830 PM. Topic: Atlantis, the End of Americas Shuttle Program, Orion, SpaceX, CST-100 and the Future of NASA Human & Robotic Spaceflight

Posted on by Amy Shira Teitel

New Data Find a Silver Lining of Cosmic Radiation

Artist's illustration of the Lunar Reconnaissance Orbiter. CRaTER is the instrument center-mounted at the bottom of LRO. Credit: Chris Meaney/NASA.

[/caption]

Cosmic radiation, it seems, may be a blessing and a curse. A team of scientists based at the University of New Hampshire have used data from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on NASA’s Lunar Reconnaissance Orbiter (LRO) to measure radiation on the Moon’s surface. They’ve found that while radiation is fatal, it can also cause the chemical changes that form the foundations of biological structures. 

CRaTER was designed to measure and characterize radiation on the Moon. It uses plastic and silicon detectors that mimic human flesh to give scientists an idea of how damaging the environment is to humans; the radiation in this case is from both galactic cosmic rays and solar energetic particles. Both these types of radiation pose a known threat to astronauts and robotic spacecraft alike.

An illustration showing the natural barrier Earth gives us against solar radiation. Credit: NASA.

NASA’s LRO has managed to gather remarkably good data. Its recent measurements were made during a quiet solar period. The lower power, pressure, fluctuations, and magnetic fluctuations of the solar wind means less interruptions. The galactic cosmic rays and solar energy particles have been able to interact more readily with detectors. Since the instruments orbit the Moon, there isn’t even an atmosphere present to shield the blow of these rays and particles.

This is a unique occurrence that has given scientists with sufficient data to validate their models of cosmic radiation. “Now we can… project GCR dose rates from the present period back through time when different interplanetary conditions prevailed,” says Nathan Schwadron, associate professor of physics at the UNH Space Science Center within the Institute for the Study of Earth, Oceans, and Space. These types of projections provide a clearer picture of the effects of cosmic rays on airless bodies throughout the Solar System’s history.

These new, more accurate models can also effectively predict radiation hazards spawned by cosmic rays and solar particles. Schwadron says that these “validated models will be able to answer the question of how hazardous the space environment is and could be during these high-energy radiation events.” Being able to anticipate high radiation events and environments will be necessary for any manned space exploration planned to go beyond low-Earth orbit.

A bootprint on the lunar regolith. Credit: NASA.

But CRaTER’s most recent finding revealed something else interesting: cosmic radiation has another important effect on the bodies it hits. While fatal to humans and damaging to robots, cosmic radiation irradiates water and ice to cause chemical alterations. The process releases oxygen atoms from water ice, which are then free to bind with carbon to form large molecules that are “prebiotic” organic molecules. The radiation process also causes the lunar soil, regolith, to darken over time. This is important in understanding the geologic history of the moon.

The data recorded on radiation environments support the current models of Earth-Moon-Mars interplanetary space. The full paper, titled “Lunar Radiation Environment and Space Weathering from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER),” was written by Schwadron and the director of EOS and lead scientist for the CRaTER instrument Harlan Spence and is published online in the American Geophysical Union’s Journal of Geophysical Research.

Source: University of New Hampshire

Posted on by Nancy Atkinson

Moon Mappers! Contribute to Lunar Science

Want to contribute to lunar science? The MoonMappers citizen science project is now live at CosmoQuest.org, and you can become part of the Lunar Reconnaissance Orbiter’s science team by exploring high-resolution Lunar images and mapping out scientifically interesting features. MoonMappers has been in a testing phase since January, and during the beta period, early participants marked over 150,000 craters and more than 4,000 other interesting features. With your help, scientists will be able to better determine ages of different regions, find historic spikes in the impact rate, determine lunar regolith depth and what may lie under the crust, and make conclusions about the physics of giant explosions on the Moon’s surface.

“Craters can reveal all sorts of different properties about the Moon and planetary surfaces in general,” said project co-science lead Stuart Robbins, from the Southwest Research Institute.
Continue reading “Moon Mappers! Contribute to Lunar Science”

Posted on by Ray Sanders

Solving the Puzzle of Apollo 12’s Mysterious Magnetic Moon Rocks

The moon's largest grouping of magnetic anomalies, on the left, is near the northern rim of the South Pole-Aitken basin, which scientists believe was created by the impact of a massive asteroid about 4.5 billion years ago. Image Credit: NASA/LRO/Science/AAAS

[/caption]

Ever since their discovery by the Apollo 12 crew, scientists have been puzzled by strongly magnetized rocks found on the Moon. Most Moon rocks that were brought back by the Apollo missions have very little iron, and therefore lack the ability to be strongly magnetized. At first, the magnetic oddities didn’t appear to be related to any lunar geology such as craters or lava flows. Over time, additional lunar missions have provided more data showing that only some portions of the Moon’s crust have magnetic fields. A team of scientists now theorize that the magnetized “patches” on the lunar surface may be the remains of an asteroid that crashed into the Moon shortly after its formation nearly 4.5 billion years ago. The impact crater, known as the South Pole-Aitken basin is one of the largest known in our Solar System.

Mark Wieczorek (Paris Institute for Global Physics), describes the South Pole-Aitken basin as, “this huge, whopping crater that’s roughly half the size of the U.S,” and says it may hold the answers to the mystery of the Apollo 12 rocks.

The Apollo 12 landing site as seen by LRO. Credit: NASA/GSFC/Arizona State University

Studies of the basin show that it is elliptical which suggests the impact was by a large object that hit at an oblique angle. Wieczorek speculates that the impactor was 10% to 30% iron by weight and about 100 times more magnetic than the lunar regolith. Interestingly enough, the theorized impact angle would have flung debris from the object in a pattern very similar to the observed magnetic anomalies. The material could have been magnetized as it cooled by a magnetic field that may have existed early in our Moon’s history.

Wieczorek and his team set out to test their theories with computer simulations of different types of impacts. The research led to a scenario where an object struck the Moon at about a 45 degree angle with a velocity of 15 kilometers per second. The team’s best impact model was described as normal by Wieczorek who stated, “We don’t require improbable conditions.”

Now the team needs to address one other question: How and when did a magnetic field develop on the Moon?

Wieczorek offers a simple solution: Go back to the moon and collect samples.

Source: NASA Lunar Science Institute