Showing posts with label Bullialdus. Show all posts
Showing posts with label Bullialdus. Show all posts

Sunday, September 8, 2013

Signs of 'Life' on the Lunar Frontier

Bullialdus-Clementine-RGB
The lunar crater Bullialdus (20.7° S, 22.2° W; 60 km diameter), with water-bearing minerals identified in the central peaks.  Clementine false-color composite over LROC WAC monochrome mosaic base [NASA/DOD/GSFC/ASU].
Paul D. Spudis
The Once and Future Moon
Smithsonian Air & Space

Generally speaking, I hate “mop up” posts wherein stories, anecdotes, factoids and announcements are lumped together solely for the purpose of clearing the writer’s desk.  But that’s what I have here, so let’s get on with it.

Despite being written off by many as a dead letter topic, the Moon (an object of scientific and commercial interest and utility) continues to confound experts and frustrate naysayers.

You may have recently learned about yet another discovery of lunar water.  The “new” this time around is that we have apparently succeeded in identifying a form of hydration (i.e., the OH molecule) present in mineral structures in the central peak of the mid-latitude crater Bullialdus (20.7° S, 22.2° W; 60 km diameter).  Past identifications of lunar water involve either the polar dark regions or high-latitude, solar wind implanted OH and H2O molecules.

We’ve known about water-bearing minerals in the lunar samples for the past couple of years, but this is the first time we have identified them using remote sensing.  This water is present in extremely minute amounts (tens of parts per million); it has nothing to do with the possibility of extracting water for human use, but rather, is a clue to the hydration state of the deep interior, and ultimately, the origin of the Moon.

We are finding that the early Moon had its own indigenous water, not an obvious consequence of the giant impact origin model, and that this water participated in early melting events.  Water is an important compound in these processes by lowering the threshold temperatures of various significant reactions and creating an environment in which explosive, volatile-charged volcanic eruptions may occur.  Work continues on understanding the meaning and significance of this interior water to the geological processes of the Moon.

The latest edition of the Global Space Exploration Roadmap has been released and to the astonishment of the press and many other observers, human lunar return is still prominently featured (minus NASA) in the strategic pathways considered by the world’s space agencies.  This shouldn’t really surprise anyone – the international partners were taken aback (and angered) by the unilateral renunciation of lunar return by the U.S. in 2010.  They have remained firm and consistent in their belief and knowledge that the Moon is a critical step toward developing genuine space faring capability, a path which they have no intention of abandoning.  In this, our partners show more insight and sophistication than we do.  There are simply too many advantages in developing technology and practicing operational skills on the Moon, all applicable to future human missions beyond low Earth orbit.  In a sop to the reluctant Americans, human near-Earth asteroid missions are mentioned.  But in the minds of the international partners, the benefits of human lunar return will not be subsumed by a domestic political agenda.

I am an occasional member and contributor to the Lunar Exploration and Analysis Group (LEAG), an informal working group of lunar scientists, engineers and developers who have devised a “roadmap” (i.e., a sequenced, strategic plan) for lunar exploration.  This roadmap has been completed and we have developed a couple of ancillary products – an executive summary booklet (being readied for distribution), which will describe the major findings of the three-year road mapping exercise.  It will be illustrated by wonderful Technicolor artwork of missions and surface activities (the creation of pretty pictures and graphics we have down pat), and a one-page “fact sheet” describing the value and rationale for human lunar return. The compact fact sheet is particularly good.  It summarizes the main points about lunar return, its value to the nation and to science and society in general.  This roadmap follows a lot of the concepts about which I write.  If you visit Develop Cislunar Space Next, you will recognize many of the same themes and ideas.  I am very happy with this product; it is concise and well crafted.  I thank my LEAG colleagues for their scientific insight and technical acumen.

About 15 years ago, I wrote a reasonably well-received book published by the Smithsonian Institution Press titled The Once and Future Moon.  In it I described the then-recent findings from the Clementine and Galileo missions about the Moon’s processes and history, and summarized what we had learned about the Moon from the Apollo missions.  I also took the opportunity to make the case for a return to the Moon (some things never change) and how we might use it to create new capabilities in space.  That book is now out of print, as well as rendered somewhat antiquated by the explosion this last decade of new information from data returning from lunar robotic missions and subsequent studies.  Many have urged me to revise that book and I am considering writing an updated second edition.  Unfortunately, the Smithsonian Press terminated their “Library of the Solar System” series and is not interested in publishing a new edition (but will give me copyright to the material).  I am investigating the interest of other publishers and will keep you posted on what develops.

Next – an announcement.  For some time I have watched the progress of many of the Google Lunar XPRIZE competitors.  It’s a mixed bag, with some teams pretty much out of the running and some who have a decent chance to actually fly a mission.  I have been very impressed with the team and the approach of one company, Moon Express (MoonEx), located at NASA Ames Research Center in California.  Moon Express has plans for small and medium class lunar landers, using a soon-to-be-unveiled design that seems both robust and affordable.  I have agreed to be associated with them on a part-time basis as their Chief Scientist.  As such, I will evaluate possible mission scenarios and profiles, devise sample payloads, identify possible instruments and their investigators and vendors, and help define measurement requirements and operational scenarios.

I like working with small missions (my first mission experience was with Clementine (1994) a small DOD-NASA mission, and I was the Principal Investigator for the Mini-SAR radar experiment on India’s Chandrayaan-1 mission) and believe that these small missions deliver a lot of scientific and exploratory bang for a reasonably small amount of bucks.  I have worked previously on projects with some of the Moon Express personnel, including Principal Systems Engineer Steve Bailey on the world’s first private lunar lander project (Blastoff.com in the late 1990s) and with CEO Bob Richards, when we were both affiliated with Odyssey Moon a few years ago.  I am also happy that my longtime colleague and NASA Advisory Council member Jack Burns has joined the company on a similar part time basis as Chair of the Moon Express Science Advisory Board.  I look forward to helping Moon Express achieve their goal of winning the Google Lunar XPRIZE and developing a truly commercial system to deliver payloads to the Moon.

Look for an article on the origin of the Moon written by yours truly, coming soon to a special web-based edition of Astronomy magazine.  I’ll post the information when it appears.  My recent post here at Air & Space describes the call for small lunar lander missions.  The last of the (currently planned) NASA missions to the Moon (was launched Friday, September 6, 2013.  Here’s wishing LADEE a safe, successful and productive journey.

So I’m happy to report that there are signs of “life” about our future on the lunar frontier.

Related Posts:
More water at lunar equator, hints of water below (August 27, 2013)
GSFC releases LEND lunar water demonstration (June 3, 2013)
Earth and Moon share primal water source (May 10, 2013)
Water found in the Apollo 15 'Genesis Rock' (February 19, 2013)
Bullialdus central peak oblique (January 23, 2013)
Reflecting on the ice of Mercury and the Moon (December 3, 2012)
Water from the Sun (October 17, 2012)
Central peak of Bullialdus (May 12, 2010)

Originally published September 5, 2013 at his Smithsonian Air & Space blog The Once and Future Moon, Dr. Spudis is a senior staff scientist at the Lunar and Planetary Institute. The opinions expressed are those of the author but are better informed than average.  

Tuesday, August 27, 2013

More water at lunar equator, hints of water below

Bullialdus Interior Oblique
Investigations of the central peaks (where the deepest material these kinds of craters excavate is deposited) of nearside equatorial crater Bullialdus (60.7 km, 20.7°S, 337.8°E) have detected rocks composed of magmatic water of a kind collected by Apollo using the NASA M3 radar instrument aboard the ISRO orbiter Chandrayaan-1. LROC Narrow Angle Camera (NAC) oblique observation M1099038207LR, spacecraft orbit 14313, August 8, 2012; overall resolution 2.4 meters, angle of incidence 48.8° with spacecraft and camera slewed 63.4° west of nadir, 73.65 kilometers over 20.96°S, 331.93°E [NASA/GSFC/Arizona State University].
NASA-funded lunar research has yielded evidence of water locked in mineral grains on the surface of the moon from an unknown source deep beneath the surface.

Using data from NASA's Moon Mineralogy Mapper (M3) instrument aboard the Indian Space Research Organization (ISRO) Chandrayaan-1 spacecraft, scientists remotely detected magmatic water, or water that originates from deep within the moon's interior, on the surface of the moon.

The findings, published by letter, August 25, in Nature Geoscience, represent the first detection of this form of water from lunar orbit. Earlier studies had shown the existence of magmatic water in lunar samples returned during the Apollo program.

M3 imaged the lunar impact crater Bullialdus, which lies near the lunar equator. Scientists were interested in studying this area because they could better quantify the amount of water inside the rocks due to the crater's location and the type of rocks it held. The central peak of the crater is made up of a type of rock that forms deep within the lunar crust and mantle when magma is trapped underground.

"This rock, which normally resides deep beneath the surface, was excavated from the lunar depths by the impact that formed Bullialdus crater," said Rachel Klima, a planetary geologist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

"Compared to its surroundings, we found that the central portion of this crater contains a significant amount of hydroxyl - a molecule consisting of one oxygen atom and one hydrogen atom -- which is evidence that the rocks in this crater contain water that originated beneath the lunar surface," Klima said.

LROC Wide Angle Camera (WAC) 100 meter per pixel mosaic of Bullialdus, an illustration for the post "Bullialdus Central Peak Oblique," January 23, 2013 [NASA/GSFC/Arizona State University].
In 2009, M3 provided the first mineralogical map of the lunar surface and discovered water molecules in the polar regions of the moon. This water is thought to be a thin layer formed from solar wind hitting the moon's surface. Bullialdus crater is in a region with an unfavorable environment for solar wind to produce significant amounts of water on the surface.

"NASA missions like Lunar Prospector and LCROSS (the Lunar Crater Observation and Sensing Satellite) and instruments like M3 have gathered crucial data that fundamentally changed our understanding of whether water exists on the surface of the moon," said S. Pete Worden, center director at NASA's Ames Research Center in Moffett Field, Calif. "Similarly, we hope that upcoming NASA missions such as the Lunar Atmosphere and Dust Environment Explorer, or LADEE, will change our understanding of the lunar sky."

Combined data for the Bullialdus area
Figure 5 from "One Moon, Many Measurements 3: Spectral reflectance," Science Direct (Icarus, Vol 226, #1, Sept.-Oct. 2013) Combined data for the Bullialdus area. (a) Location of available datasets of the Bullialdus region: gray scale base map, MI; red dots, SP traverses; blue shading, M3 scene width; light-blue dots, SIR-2 traverses. SP/M3/SIR-2 datasets within the white box are presented in this figure. The white box corresponds to the area shown in (b) and (c). TC data cover the entire area. Data included in Table 2 for SP are indicated in yellow, and those for SIR-2 are solid light blue. (b) M3 color-composite image. Band assignments are integrated band depth at 1 μm (red), integrated band depth at 2 μm (green), and 1.5 μm albedo (blue). A manual shadow mask has been applied, primarily on the west (left) crater wall. (c) MI color-composite image. Red denotes the continuum-removed absorption depth of 0.95 μm, green denotes that of 1.05 μm, and blue denotes that of 1.25 μm. (d) TC image of the central part of the Bullialdus central peak. (e) MI 750 nm-band image after photometric correction using local topographic information. (f) MI color-composite image of the center of the Bullialdus central peak. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

The detection of internal water from orbit means scientists can begin to test some of the findings from sample studies in a broader context, including in regions that are far from where the Apollo sites are clustered on the near side of the moon. For many years, researchers believed that the rocks from the moon were bone-dry and any water detected in the Apollo samples had to be contamination from Earth.

"Now that we have detected water that is likely from the interior of the moon, we can start to compare this water with other characteristics of the lunar surface," said Klima. "This internal magmatic water also provides clues about the moon's volcanic processes and internal composition, which helps us address questions about how the moon formed, and how magmatic processes changed as it cooled."

APL is a not-for-profit division of Johns Hopkins University. Joshua Cahill and David Lawrence of APL and Justin Hagerty of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Arizona co-authored the paper.

NASA's Lunar Advanced Science and Engineering Program, the NASA Lunar Science Institute (NLSI) at Ames and the NASA Planetary Mission Data Analysis Program supported the research. NLSI is a virtual organization jointly funded by NASA's Science Mission Directorate and NASA's Human Exploration and Operations Mission Directorate in Washington, to enable collaborative, interdisciplinary research in support of NASA lunar science programs.

Wednesday, January 23, 2013

Bullialdus Central Peak Oblique

The central peak of Bullialdus rises above the crater floor with the crater wall in the background. LROC Narrow Angle Camera (NAC) oblique (63.36° slew from nadir) M1099038207LR, LRO orbit 14313, August 8, 2012 (north to the left) resolution in foreground 2.31 meters from 73.65° over 20.96°S, 331.93°E [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

Bullialdus is a complex crater located in the western part of Mare Nubium, at 20.7°S, 337.8°E (60.7 km diameter). Like all complex craters, Bullialdus has terraced inner walls and a central peak. The Featured Image shows an oblique view, taken from the West looking east at the eastern crater wall (north is to the left). The central peak towers 1.1 km above the flat crater floor. This NAC pair was taken while LRO was ~74 km above the lunar surface. This central peak may hold clues to the composition of materials deep within the Moon's crust.

Large complex craters excavate material from great depths in the lunar crust. The central peak is formed shortly after the bolide impact. While material is excavated and ejected to form the crater cavity, the ground at the center of the impact elastically rebounds after the shock and pressure. The material in the central peak originates from the deepest point in the lunar crust compared to the ejecta and rim material. These central peaks give scientists an opportunity to study the composition of the lower crust and upper mantle in order to understand how planets form and evolve over time.

LROC Wide Angle Camera (WAC) 100 meter per pixel mosaic of Bullialdus [NASA/GSFC/Arizona State University].
While the circular shape of the crater rim is degraded by slumping, the morphology of the crater's ejecta blanket is still visible. The persistence of the ejecta blanket morphology is an indicator that helps scientists estimate the age of the crater. Since the ejecta blanket hasn't been destroyed by subsequent impacts (micrometeorites and larger bolides), it means that Bullialdus is Eratosthenian in age (somewhere between 1.1 and 3.2 billion years old). You can compare the differences between Bullialdus and the crater Tycho, which is only 110 million years old. In the WAC context image (above) and digital terrain image (below) a smaller crater can be seen along the southeastern rim of Bullialdus. This crater (Bullialdus A) is clearly older than Bullialdus since ejecta from Bullialdus partially fills the interior of Bullialdus A. Bullialdus A is also non-circular in shape and it may have been deformed by the impact that created Bullialdus.

Colorized topography of Bullialdus [NASA/GSFC/Arizona State University].
Explore the entire oblique NAC, HERE.

Related Images:
New oblique view of Tsiolkovskiy Central Peak
Aristarchus Cobra Head

Icarus
Central Peak of Bullialdus Crater
Southside, Aristarchus Crater
Tycho Central Peak Spectacular!
Aitken Central Peak, Seen Obliquely