An Oval Crater on Harvey's Wall

A bolide impacting into the sloping south wall of Harvey crater formed an oval rather than circular crater. A 1.32 km-wide field of view cropped from LROC Narrow Angle Camera (NAC) observation M191567120R, LRO orbit 13268, May 13, 2012; 56.78° angle of incidence, resolution 1.36 meters from 136.22 km [NASA/GSFC/Arizona State University].

Lillian Ostrach
LROC News System

Non-circular (oval or elliptical) impact craters can form when the impacting bolide trajectory to the surface is less than 15° from horizontal or when the bolide impacts a sloped region on the (or some combination of both factors). 

This young crater (18.855°N, 213.180°E) formed on the sloping southern wall of Harvey crater, which is very degraded, and may be an example in which target surface slope controlled final crater shape (as opposed to impact angle). The crater is oval-shaped, measuring ~735 m across and ~780 m in the north-south direction.

A closer look, under a higher sun, allows a detailed view of the bright ejecta of the crater of interest. (View the very large, full-sized mosaic HERE.) Full 3 km-width field of view from LROC NAC M138506456L, orbit 5545, September 7, 2010; 29.65° angle of incidence, resolution 66 cm from 63.83 km [NASA/GSFC/Arizona State University].

The southern half of the crater has a well-defined, sharp rim with some concentric fractures (particularly visible on the southwestern rim area) while the northern rim is ill-defined.

LROC Wide Angle Camera (WAC) monochrome mosaic of Harvey crater (19.35°N, 213.49°E, ~60 km diameter). The fresh, oblique impact shown in the LROC Featured Image is on the crater wall, "like flour dropped on the floor," is below left center [NASA/GSFC/Arizona State University].

The poorly-developed northern rim indicates that the impact trajectory probably traveled from the south/southwest toward the north/northeast. In a lower incidence angle image (Sun approaches "noon" position overhead), the albedo variations emphasize the high-reflectance ejecta blanket (observed in the WAC mosaic below) and observations of the ejecta blanket, including the zone of avoidance, help confirm the bolide trajectory.

Harvey, in strategraphic context, itself nested on the northeastern rim of Mach. An arch rim of of an older crater can be seen to the north. The region is further effected by secondary craters from the Mare Orientale impact and elsewhere. LROC WAC-derived digital terrain model [NASA/GSFC/Arizona State University].

LROC NAC images reveal the presence of unexpected ponds of impact melt in small lunar craters. Taking a look at the northern portion of this small crater, there is a smooth deposit with slightly lower reflectance than the surrounding materials. This smooth material is probably a small pond of impact melt, generated during impact. Impact melt is likely distributed elsewhere within the crater as thin veneers, perhaps on the southern wall where there are lower-reflectance smooth streaks, and probably mixed in with the fragmented debris that were not ejected from the crater.

Explore this oval crater for yourself in the full LROC NAC image, HERE.

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Inertia curves a Far Side boulder uphill?

Looking through the images and data released to the Planetary Data Systemas part of an informal test by the Lunar Reconnaissance Orbiter Camera (LROC) team at Arizona State University, we poured over a rich boulder landslide field near 233.93°E, 24.46°S, or approximately 100 kilometers west by southwest of the Gerasimovich Swirl. We almost missed it, but our eyes were eventually drawn deep into the long shadows before sunset under LRO Orbit 347. Among many boulder trails we seem to have found one that's a little different. A rather sizable boulder appears to have rolled first downhill, as part of a larger chunk of debris. Part of it seems to actually have rebounded briefly and curved on a terrace back uphill. It then seems to have become lodged into the grade and then afterward become dislodged again, tipping forward where now rests [NASA/GSFC/Arizona State University].

Far Side's Sea of Moscow, from Kaguya

Although Charles Wood at LPOD was first to give us heads up on Japan's spectacular Kaguya Terrain Camera tour of Mare Moscoviense (Sea of Moscow), Juna Terazono can be credited with being the first to officially notify us about its existance, in an Email sent out to the "Lunatics" on the Lunar-L, Sunday, February 8.

The reduced image accompanying this post, as spectacular as it might seem, does no justice whatsoever, either to the still image or the MPEG that is available for full screen downloading, unzipping and full screen viewing immediately, from the Japanese language side of the newly renovated Kaguya Image Gallery.

Fortunately for those who make a daily stop at LPOD, Charles Wood let us in on the update on December 10. From that LPOD posting, you can immediately be treated to a larger version of the image here, and, trust me, it's worth it. Charles Wood also provide his own unique background at the LPOD site, into this "window into the interior of the Moon," where Japan's investigators have found signs of "relatively" recent lunar morphology, particularly volcanism.

The Kaguya Terrain Camera MPEG is available HERE, Juna reminds us, "Please click the "MPEG-2" button to download the ZIP archived video. Like other movies," those hung up on "some platforms, (may) experience some difficulties in playing" the MPEG.

I experienced no difficulties, whatsoever, except the need to keep my tongue off my chin, as I was taken downward, into the image here, for a slow flyover of the submerged craters lined up in
the lower left, a swing around Titov Crater and around the rim, again slowly, to finally end up with a detail look into the rectilinear formation just to the right. If the latter had been imaged alone and presented to me as a holy place of the Navaho, I would have probably believed it.

My only twiddling disappointment was in noting my best attempts to identify any distinct Swirl Albedo formations was frustrated by the prominent rim shadowing the mare "sea floor" at the upper left of the formation. The best candidates fall directly inside that shadow.

Regardless of your level of familiarity with lunar cratering, volcanism, domes, lava tubes, "sea" formation, or of the Moon as a whole, this being a very exceptional formation for the Far Side, characterized by bright anorthositic highland craters, like those seen between the seas on the Earth-facing Near Side, you are bound to enjoy this tour.

I hope this is just a taste of the kinds of materials made possible by the collected Kaguya data long after the probe is de-orbited later this year.

Naval Research Laboratory to design Farside DALI

The Dark Age Lunar Interferometer (DALI) apparently planned for multi-robot deployment from Tsiolkovsky

Contact: Donna McKinney
(202) 767-2541
Naval Research Laboratory

A team of scientists and engineers led by the Naval Research Laboratory (NRL) will study how to design a telescope on the Moon for peering into the last unexplored epoch in the Universe’s history. NASA has announced that it will sponsor a series of studies focusing on next-generation space missions for astronomy. These studies will contribute to the Decadal Survey, an effort undertaken every 10 years by astronomers and physicists to help establish priorities for future research directions in astronomy and astrophysics. The upcoming Decadal Survey occurs over the next two years.

Among the missions to be studied is the Dark Ages Lunar Interferometer (DALI), the NRL-led concept for a telescope based on the Moon and studying an era of the young Universe, during the first 100 million years of its existence. Although the night sky is filled with stars, these stars did not form instantaneously after the Big Bang. There was an interval, now called the “Dark Ages,” in which the Universe was unlit by any star. The most abundant element in the Universe, and the raw material from which stars, planets, and people are formed, is hydrogen. Fortunately, the hydrogen atom can produce a signal in the radio-wavelength part of the spectrum, at 21 cm; a wavelength far longer than what the human eye can detect. If these first signals from hydrogen atoms in the Dark Ages can be detected, astronomers can essentially probe how the first stars, the first galaxies, and ultimately the modern Universe evolved.

Because the Universe is expanding, the signals from these distant hydrogen atoms will be stretched (or redshifted) to much longer wavelengths, as large as several meters. While astronomical observations at radio wavelengths have a long history, this portion of the electromagnetic spectrum is now heavily used for various civil and military transmissions, all of which are millions of times brighter than the hydrogen signal that astronomers seek to detect. Additionally, the upper layers of the Earth’s atmosphere are ionized (the ionosphere), which introduce distortions into astronomical signals as they pass through on their way to telescopes on the ground.

With no atmosphere and shielding from the Earth, the far side of the Moon presents a nearly ideal environment for a sensitive Dark Ages telescope. In NRL’s DALI concept, scientists and engineers will investigate novel antenna constructions, methods to deploy the antennas, electronics that can survive in the harsh lunar environment, and related technology in preparation for developing a roadmap for research and development of a lunar telescope over the next decade. The team will also build on their experience in developing the Radio Observatory for Lunar Sortie Science, a NASA-funded study of a pathfinding array that would be located on the near side of the Moon.

The project leader at NRL, Dr. Joseph Lazio, pointed out that DALI will be one of the most powerful telescopes ever built and will bring us closer than we have ever been to understanding where our Universe came from and where it is going. “Probing the Dark Ages presents the opportunity to watch the young Universe evolve,” Dr. Lazio said. “Just as current cosmological studies have both fascinated and surprised us, I anticipate that DALI will lead both to increased understanding of the Universe and unexpected discoveries.”

When asked about the program, NRL Senior Astronomer Dr. Kurt Weiler remarked: “Building telescopes on the Moon is clearly a long-term project, but I am very excited about us getting started on this proposal.”
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Scientists and engineers from institutions and NASA centers around the country are participating in the Dark Ages Lunar Interferometer study, including NASA/Goddard Space Flight Center, Caltech/Jet Propulsion Laboratory, the University of Colorado, the Smithsonian Astrophysical Observatory, the National Radio Astronomy Observatory, University of California-Los Angeles, University of California-Berkeley, the University of New Mexico, and Virginia Polytechnic Institute and State University (VA Tech).

Telescopes on the Far Side of the Moon

A follow up to the series, such as it is, by Washington Post staff writer Marc Kaufman

"Since the beginning of the space age, astromers have dreamed of putting telescopes and other instruments on the far side of the moon, and now with NASA planning to send astronauts back to the moon sometime after 2019, those dreams of a radio telescope looking out through the galaxies from the protected side of the moon have been revived."

Readers Joined Kaufman on Tuesday for a discussion about the latest news, which he reports in the Monday Science Page story.

A transcript follows.

Poster answered by Knight Tracker on Farside LARC

LNEDNOTE: The poster below obviously isn't looking very hard for the news about MIT's Farside Radio Astronomy project, and from what follows appears also to have failed even to read MIT's original News Release: LARC is tentatively planned as strikingly simple, robot-deployed project. Also, the final $1 Billion price tag picked from thin air, apparently, is based on the development of the kind of robot that will eventially be needed throughout the field of Selenology, and in the immediate future. It is also less than the cost of a single Shuttle flight. (Anyone for Mass production, perhaps on the Moon itself? It would certainly be cheaper than lobbing them up and out of Earth's Gravity Well.)

Put more simply, Farside radio astronomy is coming, sooner or later. LARC will be only the beginning of what is bound to become a intregral part of a new, incredibly sensitive and practical space-based, Earth-based and Moon-based Ultra-Ultra Long Baseline Interferometry and new Deep Space Network.

ORIGINAL POST: MIT has a press release out saluting itself for winning part of a $500,000 grant to scope out a plan by some of its astronomy and physics professors to install, on the quiet side of the moon (away from civilization’s electromagnetic cacophony), a scattering of radio receivers. It’d be LARC, for Lunar Array for Radio Cosmology. There they would pick up long wavelength emissions left over from the early universe’s dark ages. That’s the span between the fading of the big bang’s explosive glow and the appearance of starry galaxies. One might learn clues to how early mass fluctuations organized themselves on a large scale.

This would neatly fill a hole in astronomy’s instrument lineup. Not many outlets, so far, have picked it up - and there’s no big reason to give such a tentative exploration of a possible project big play. The Tracker could find but two stories, each just this side of a brief.

But those of us of suspicious mind might enjoy some deeper inspection of this plan, one of several proposals knocking about and given longterm analysis money by NASA recently. The question is whether the proposal in any way would depend on, or just benefit from, astronauts as construction workers and maybe as technician-repair crews. Which is to say, is there any way such a worthy, if costly (estimated $1 billion) project’s prospects will get tangled up in NASA’s Constellation program to get people back on the moon? It is an ambition that seems sure to get reinspection upon arrival of a new administration in less than a year. More generally, the whole, winding and roundabout way that NASA’s mega-dollar projects go from blue-sky idea to launch pad could use a little more, if only occasional, media attention.

Read the Screed

Boston Herald Mike Underwood ; Wired John Borland ;
MIT Press Release ; NASA Press Release on full, recent round of long range study contracts.

And MIT's Knight Science Tracker sets the record straight well today HERE.

Telescopes on Lunar FarSide 'Revived'

By Marc Kaufman
Washington Post Staff Writer

"Not only would that avoid all the distortions and disturbances caused by Earth's turbulent atmosphere, but equally important, the moon's mass would block the noisy torrent of radio signals emanating from Earth. Only in the moon's radio "shadow" could the farseeing radio telescopes envisioned for the future pick up the extremely faint signals left over from the early universe, signals that would otherwise be drowned out by the broadcast barrage from Earth."

LNBLOG EDITORS NOTE: Some of us never stopped thinking about the Farside's "radio-quiet" as the place to begin direct and 400,000 kilometer long baseline interferometry. How, then, is this concept "revived?" And weren't Farside landings well within the capabilities of the Apollo Program, perhaps at Coriolis and other likely Farside equatorial spots? The problem of how to relay the data from such a site and the limitations placed on the instrument package by weight, 1969 sophistication and size would have presented quite a quandary. And high-end frequency communication we take for granted in the GHz range was barely the stuff of Extra-Class ham radio experiments at the time. Imagine, however, where the state of both radio astronomy and perhaps Lunar exploration might have been if this unoriginal idea had been followed through, at the expense of trusting experimental landings to astronauts with buggy, unimaginably slow computers without the aid of Houston's watchful eye. Though admittedly difficult, and a likely cause very high groundside anxiety, it still seems a Farside landing might well have been within the realm of possibility for Apollo -if it had been a priority.

As future problems arise (such as sticky questions like how to retrieve and restore the Apollo 11 ascent stage blow-over of the original American Flag placed at Tranquillity by Neil Armstrong and Edwin Aldrin in July 1969, without disturbing those historic first foot prints) Lunar Networks will be asked to review present day news to discover such dilimia. In the case of the long-acknowledged distinctly anthropomorphic radio-quiet for radio astronomy on the Lunar Farside, how much of a problem will the inherently unstable orbits and spurious emissions from LPS/Cellular satellites needed for exploration of the Moon become for the planned (and important) Deep Space Radio Telescopes, and their controllers?

Answers to such questions are welcome.

Meanwhile, read the remainder of this late article from today's Washington Post.

MIT To Lead Development Of New Radio Telescope Array On Lunar Farside

by David Chandler
MIT News
Boston - NASA has selected a proposal by an MIT-led team to develop plans for an array of radio telescopes on the far side of the moon that would probe the earliest formation of the basic structures of the universe. The agency announced the selection and 18 others related to future observatories on Friday, Feb.15.

The new MIT telescopes would explore one of the greatest unknown realms of astronomy, the so-called "Dark Ages" near the beginning of the universe when stars, star clusters and galaxies first came into existence.

This period of roughly a billion years, beginning shortly after the Big Bang, closely followed the time when cosmic background radiation, which has been mapped using satellites, filled all of space.

Learning about this unobserved era is considered essential to filling in our understanding of how the earliest structures in the universe came into being.

The Lunar Array for Radio Cosmology (LARC) project is headed by Jacqueline Hewitt, a professor of physics and director of MIT's Kavli Institute for Astrophysics and Space Science. LARC includes nine other MIT scientists as well as several from other institutions.

It is planned as a huge array of hundreds of telescope modules designed to pick up very-low-frequency radio emissions. The array will cover an area of up to two square kilometers; the modules would be moved into place on the lunar surface by automated vehicles.

Observations of the cosmic Dark Ages are impossible to make from Earth, Hewitt explains, because of two major sources of interference that obscure these faint low-frequency radio emissions. One is the Earth's ionosphere, a high-altitude layer of electrically charged gas. The other is all of Earth's radio and television transmissions, which produce background interference everywhere on the Earth's surface.

The only place that is totally shielded from both kinds of interference is the far side of the moon, which always faces away from the Earth and therefore is never exposed to terrestrial radio transmissions.

Besides being the top priority scientifically for a telescope on the moon, this low-frequency radio telescope array will also be one of the easiest to build, Hewitt says.

That's because the long wavelengths of the radio waves it will detect don't require particularly accurate placement and alignment of the individual components. In addition, it doesn't matter if a few of the hundreds of antennas fail, and their performance would not be affected by the ever-present lunar dust.

The new lunar telescopes would add greatly to the capabilities of a low-frequency radio telescope array now under construction in Western Australia, one of the most radio-quiet areas on Earth. This array, which also involves MIT researchers, will be limited to the upper reaches of the low-frequency radio spectrum, and thus will only be able to penetrate into a portion of the cosmic Dark Ages.

According to prevailing theory, this unobserved span of time in the universe's infancy includes a period when dark matter--an unknown component of the universe that accounts for a majority of all matter--collapsed from a uniform soup of particles into clumps that formed the scaffolding for all the structures that emerged later, from stars and black holes to entire galaxies.

All astronomical observations made so far only reveal the results of that whole formation process--except the cosmic background radiation, which only shows the raw material before the process began. The whole gestation and birth of all the kinds of objects seen in space today, which all took place in the Dark Ages, has so far been hidden from view.

The new observations could test current theories about how the universe formed and evolved into its present state, including the theory of cosmic inflation first proposed by MIT Professor Alan Guth.

In addition to their primary mission, the new telescopes would also be useful for studying huge eruptions from the sun, called coronal mass ejections, which can sometimes disrupt communications and electrical grids on Earth. They could also study space weather, the radio emissions from other planets and emissions from collisions between galaxies.

The present plan is for a one-year study to develop a detailed plan for the telescope array, whose construction would probably not begin until sometime after the year 2025, and is expected to cost more than $1 billion.
The project to develop the plan is led by MIT's Hewitt, with a team that includes MIT professors Jeffrey Hoffman of the Department of Aeronautics and Astronautics and Maria Zuber, chair of the Department of Earth, Atmospheric and Planetary Sciences, as well as others from MIT and scientists from Harvard, the National Radio Astronomy Observatory, the University of California at Berkeley, University of Washington and NASA's Jet Propulsion Laboratory.
To develop this detailed plan, NASA is awarding a grant of $500,000, to be divided between the MIT-led team and a second team that is independently developing a similar proposal, headed by scientists at the Naval Research Laboratory.