Estimates of the amount of water outgassed from Mars, based on the composition of the atmosphere, range from 6 to 160 m, as compared with 3 km for the Earth. In contrast, large flood features, valley networks, and several indicators of ground ice suggest that at least 500 m of water have outgassed. The two sets of estimates may be reconciled if early in its history, Mars lost part of its atmosphere by impact erosion and hydrodynamic escape.

Water on Mars

High-resolution gravity data obtained from the dual Gravity Recovery and Interior Laboratory (GRAIL) spacecraft show that the bulk density of the Moon's highlands crust is 2550 kilograms per cubic meter, substantially lower than generally assumed. When combined with remote sensing and sample data, this density implies an average crustal porosity of 12% to depths of at least a few kilometers. Lateral variations in crustal porosity correlate with the largest impact basins, whereas lateral variations in crustal density correlate with crustal composition. The low-bulk crustal density allows construction of a global crustal thickness model that satisfies the Apollo seismic constraints, and with an average crustal thickness between 34 and 43 kilometers, the bulk refractory element composition of the Moon is not required to be enriched with respect to that of Earth.

/pdf/the-crust-of-the-moon-as-seen-by-grail-1glf8bzv6k.pdf

The Crust of the Moon as Seen by GRAIL

Lunar sourcebook. A user's guide to the moon

Progress in probability density function methods for turbulent reacting flows

The Holy GRAIL? The gravity field of a planet provides a view of its interior and thermal history by revealing areas of different density. GRAIL, a pair of satellites that act as a highly sensitive gravimeter, began mapping the Moon's gravity in early 2012. Three papers highlight some of the results from the primary mission. Zuber et al. (p. 668, published online 6 December) discuss the overall gravity field, which reveals several new tectonic and geologic features of the Moon. Impacts have worked to homogenize the density structure of the Moon's upper crust while fracturing it extensively. Wieczorek et al. (p. 671, published online 6 December) show that the upper crust is 35 to 40 kilometers thick and less dense—and thus more porous—than previously thought. Finally, Andrews-Hanna et al. (p. 675, published online 6 December) show that the crust is cut by widespread magmatic dikes that may reflect a period of expansion early in the Moon's history. The Moon's gravity field shows that the lunar crust is less dense and more porous than was thought. High-resolution gravity data obtained from the dual Gravity Recovery and Interior Laboratory (GRAIL) spacecraft show that the bulk density of the Moon's highlands crust is 2550 kilograms per cubic meter, substantially lower than generally assumed. When combined with remote sensing and sample data, this density implies an average crustal porosity of 12% to depths of at least a few kilometers. Lateral variations in crustal porosity correlate with the largest impact basins, whereas lateral variations in crustal density correlate with crustal composition. The low-bulk crustal density allows construction of a global crustal thickness model that satisfies the Apollo seismic constraints, and with an average crustal thickness between 34 and 43 kilometers, the bulk refractory element composition of the Moon is not required to be enriched with respect to that of Earth.

The crust of the Moon as seen by GRAIL

In this paper, we would revisit the usability of microwave for lunar regolith sintering through an in-depth experiment, and examine the minimum materials and energy required for sintering based on the SinterHab design. This will include the minimum layers to print, estimated printing time, minimum energy required for the sintering process and the potential energy sources.

Estimation of Energy and Material Use of Sintering-Based Construction for a Lunar Outpost — With the Example of SinterHab Module Design

New oxygen isotopic measurements of IIEs and H chondrites are indistinguishable — strengthening a possible common origin for these groups. Combining oxygen results with mineralogy, the nature of their parent body or bodies can be explored.

/pdf/oxygen-isotopic-and-petrological-constraints-on-the-origin-3pl1z700jf.pdf

Oxygen Isotopic and Petrological Constraints on the Origin and Relationship of IIE Iron Meteorites and H Chondrites

C1XS Spectral Analysis Method

One of the important issues in lunar science relates to the understanding of the timing and duration of mare magmatism which has significant implications for the thermal evolution of the lunar interior through time. Remote sensing studies of the Moon have indicated existence of mare regions as old as 4 Ga and as young as 1 Ga. In contrast, most lab-based studies involving direct age dating of “returned” basaltic lunar samples (from Apollo and Luna missions, and lunar meteorites) by radiometric techniques have yielded much narrower age ranges for mare magmatism, typically in the time interval of 3.9 to 3.1 Ga. However, less attention have been given to some notable examples of ancient mare magmatism, samples of which exist in terms of 4.2 – 4.3 Ga basalts. Recently, a number of chronological investigations of basaltic lunar samples have revealed crystallization ages which are older, as well as, younger, than previously known range for mare basalt ages. These new findings have necessitated revisiting the topic of ages and duration of basalt volcanism on the Moon and the causes and consequences of it for the lunar evolution with implications for post-accretion planetary differentiation processes.

Timing and Duration of Mare Basalt Magmatism: Constraints from Lunar Samples

microscope of lunar meteorite Kalahari 009 – recording the oldest (4350 Ma) volcanism on the Moon! Top – whole thin-section view between crossed polars (XPL). Buttons at the bottom allow users to switch from plane polarized light (PPL) to a view between XPL, vary magnification, pan around the sample, zoom in an out of an area of interest, and measure the size of grains. Bottom – the two circular areas are rotation movies in PPL (left) and XPL (right). The user can rotate these two views simultaneously something not possible with a real microscope! SPACE EYEFUL: A VIRTUAL MICROSCOPE FOR EXTRATERRESTRIAL SAMPLES. M. Anand 1,2 , V. K. Pearson 1 , A. G. Tindle 1 , S. P. Kelley 1 , C. Koeberl 3 , C. L. Smith 2 , and P. C. Whalley 4 , 1 CEPSAR, Open University, Milton Keynes, MK7 6AA, UK (m.anand@open.ac.uk) 2 Department of Mineralogy, The Natural History Museum, London, SW7 5BD, UK. 3 Natural History Museum, Burgring 7, A-1010 Vienna, Austria. 4 Knowledge Media Institute, Open University, Milton Keynes, MK7 6AA, UK

Mahesh Anand

Papers

Estimation of Energy and Material Use of Sintering-Based Construction for a Lunar Outpost — With the Example of SinterHab Module Design

Oxygen Isotopic and Petrological Constraints on the Origin and Relationship of IIE Iron Meteorites and H Chondrites

C1XS Spectral Analysis Method

Timing and Duration of Mare Basalt Magmatism: Constraints from Lunar Samples

Space Eyeful: A Virtual Microscope for Extraterrestrial Samples