Initial results from the Optical High-Resolution camera (OHRC) onboard Chandrayaan-2

<p>Chandrayaan-2 Orbiter carries eight experiments for studies, including morphology, surface geology, composition, and exospheric measurements based upon the understanding and information from the previous lunar orbital missions. Orbiter high-resolution camera (OHRC), one of the payloads, has a very high spatial resolution of 0.25 m. It operates in a visible panchromatic (PAN) band with a swath of 3 km from an altitude of 100 km. OHRC will search for hazard-free zones and map the landing site for future human missions. This work presents the initial impressions from the first data release of the OHRC on-board Chandrayaan-2. Here the OHRC image is analyzed for large-scale features like boulders, ridges, and craters on the lunar surface. Classification and visual analysis have been carried out to check the shape (morphology) and location of many impact craters. As seen from OHRC images, the lunar surface near to Hagecius lunar impact crater is dominated by the repetitive and frequent bombardment of small meteorites varying from millimeters to centimeters. The extent of degradation and erosion of a few large craters due to space weathering or the continuous meteorite bombardment is clearly observed. The results provide more clarification towards the ongoing physical processes on the moon. OHRC image provides a much detailed understanding of lunar topography and morphology. </p>

Lunar samples record an impact 4.2 billion years ago that may have formed the Serenitatis Basin

Impact cratering on the Moon and the derived size-frequency distribution functions of lunar impact craters are used to determine the ages of unsampled planetary surfaces across the Solar System. Radiometric dating of lunar samples provides an absolute age baseline, however, crater-chronology functions for the Moon remain poorly constrained for ages beyond 3.9 billion years. Here we present U–Pb geochronology of phosphate minerals within shocked lunar norites of a boulder from the Apollo 17 Station 8. These minerals record an older impact event around 4.2 billion years ago, and a younger disturbance at around 0.5 billion years ago. Based on nanoscale observations using atom probe tomography, lunar cratering records, and impact simulations, we ascribe the older event to the formation of the large Serenitatis Basin and the younger possibly to that of the Dawes crater. This suggests the Serenitatis Basin formed unrelated to or in the early stages of a protracted Late Heavy Bombardment.

Two light sensors decode moonlight versus sunlight to adjust a plastic circadian/circalunidian clock to moon phase

Many species synchronize their physiology and behavior to specific hours. It is commonly assumed that sunlight acts as the main entrainment signal for ~24h clocks. However, the moon provides similarly regular time information, and increasingly studies report correlations between diel behavior and lunidian cycles. Yet, mechanistic insight into the possible influences of the moon on ~24hr timers is scarce. We studied Platynereis dumerilii and uncover that the moon, besides its role in monthly timing, also schedules the exact hour of nocturnal swarming onset to the nights′ darkest times. Moonlight adjusts a plastic clock, exhibiting <24h (moonlit) or >24h (no moon) periodicity. Abundance, light sensitivity, and genetic requirement indicate Platynereis r-Opsin1 as receptor to determine moonrise, while the cryptochrome L-Cry is required to discriminate between moon- and sunlight valence. Comparative experiments in Drosophila suggest that Cryptochrome′s requirement for light valence interpretation is conserved. Its exact biochemical properties differ, however, between species with dissimilar timing ecology. Our work advances the molecular understanding of lunar impact on fundamental rhythmic processes, including those of marine mass spawners endangered by anthropogenic change.