Poster presentations and abstracts

The Lunar Laser Ranging (LLR) investigations have provided time high-precision measurements of geodesy, dynamics and distance of the Earth-Moon system, and inferences about lunar interior and gravitational physics. LLR studies are supported by a total of five passive Laser Retro-Reflectors (LRR) placed on the Moon surface by the past missions Apollo-11, -14, -15 and Luna-17 and -21. The detection of their positions is decisive to improve the measurement accuracy and the data from alternative instrumentations contributed to their analysis. The Lunar Reconnaissance Orbiter Camera (LROC) operated by using the Standardized Lunar Coordinate System as reference system has acquired images of the Moon surface that represent data applicable to LLR planning and research. Several LROC images present nominal lighting conditions and solar glints reflected off of an LRR. Glints represent specular reflections of light that define higher-precision measurement of LRR position. In this way, their detection plays an important role in LRR analysis. The identification of candidate images with solar glints through time allows researchers to record these measurements. NASA and INFN-LNF (National Lab of Frascati) have collaboratively developed an LLR tool to support glint identification. The tool can be accessed using the Moon Trek (https://trek.nasa.gov/moon) which is one of the web based interactive visualization and analysis portals provided by the NASA’s Solar System Trek (https://trek.nasa.gov) project. The tool facilitates current ranging studies as well as planning of future missions that involve ranging activities such as future retroreflector deployments. Glint identification has been performed by using the LLR tool that allows us to investigate the image data, and to compute geometric calculations and LLR analyses. The tool with SPICE computations is provided to search for nominal conditions to catch a solar glint off of a retroreflector, to search for time intervals in which a reflector can be seen from a ground station on Earth, and to search in PDS database for images with these conditions. Moon Trek’s LLR tool allows us to find time intervals when spacecraft positioning was able to catch a solar glint reflected off of a retroreflector by setting the maximum incidence and phase angles. This analysis is accompanied by the search for LROC images available in Planetary Data System (PDS) that have solar glint off the LRR. Using the Moon Trek, it is possible to identify LROC images with solar glint off the LRR and to recognize optimal LROC candidates. This research allows us to identify good examples of LROC images that present solar glints. More than six candidate images over a period of 10 years of LROC data were recognized. In this contribution, we present the recognized LROC candidates and we show their detection in the image data, by avoiding the bias of the surface high albedo and the morphological pattern that can interfere with the analysis. The identification of solar glints off LRR will allow us to find previous observation that might be incorrect and to measure the LRR position in the Standardized Lunar Coordinate System of LROC images. These measures will be then compared with the ephemeris calculations obtained from LLR data.

How to cite: Rossi, C., Gallegos, N., Filomena, L., Malhotra, S., Law, E., Porcelli, L., Dell'Agnello, S., and Day, B.: LROC candidate images with solar glints off Lunar Laser Retroreflectors: A dedicated tool of NASA's Moon Trek, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-614, https://doi.org/10.5194/epsc2020-614, 2020.

1. Abstract

This presentation will outline the development status of the PROSPECT payload for Lun27 and highlight the science goals and some of the work on-going to ensure that these goals can be met.

2. Introduction

The Package for Resource Observation and in-Situ Prospecting for Exploration, Commercial exploitation and Transportation (PROSPECT) is a payload in development by ESA for use at the lunar surface. Current development is for flight on the Russian-led Luna-Resource Lander (Luna 27) mission, which will target the south polar region of the Moon. PROSPECT will perform an assessment of volatile inventory in near surface regolith (down to ~ 1 m), and analyses to determine the abundance and origin of any volatiles discovered. Lunar polar volatiles present compelling science and exploration objectives for PROSPECT, but solar wind-implanted volatiles and oxygen in lunar minerals (extracted via ISRU techniques) constitute potential science return anywhere on the Moon, independently of a polar landing site. PROSPECT is comprised of the ProSEED drill module and the ProSPA analytical laboratory plus the Solids Inlet System (SIS), a carousel of sealable ovens (for evolving volatiles from regolith).

In ensemble, PROSPECT has a number of sensors and instruments (including ion-trap and magnetic sector mass spectrometers, imagers, and sensors for temperature, pressure, and permittivity) that form the basis for a range of science investigations that are (almost all) led by the PROSPECT Science Team:

• Imaging, Surface Modelling and Spectral Analysis
• Drilling, Geotechnics and Sample Handling
• ProSPA ISRU Precursor Experiments
• ProSPA ISRU Prospecting
• ProSPA Light Elements & Isotopes
• ProSPA Noble Gases
• Thermal Environment and Volatile Preservation
• Permittivity (ESA-led)

3. Development status and current activities

PROSPECT Phase C, ‘detailed definition’, began in December 2019. A plan of research activities is in progress to gain from and guide on-going development, build strategic scientific knowledge, and to prepare for operation of the payload.

Drill Testing. Testing of the ProSEED Development Model was carried out in December 2019 as part of the final Phase B activities. Test procedures were formulated to demonstrate drilling and sampling functionality in ambient, cold and thermal vacuum (TV) laboratory conditions (at CISAS, University of Padova). Tests included drilling into, and sampling from, well-characterized NU-LHT-2M simulant mixed with anorthosite inclusions of various sizes, according to a layered scheme that describe depth-density profile and distribution of inclusions and a range of plausible water ice contents.

ProSPA Bench Development Model (BDM). The BDM of the ProSPA analytical lab at the Open University has been tested to demonstrate science performance against measurement requirements. Dedicated efforts in 2019 focused on verification of evolved gas analysis (EGA) via measurement of meteorite standards, constraint of oxygen yield via demonstration of ISRU capabilities, improving understanding of sensitivity of science requirements to regolith volatile abundance and possible contamination, and understanding the performance of oven seal materials.

4. Volatile preservation

Particular efforts since 2018 have focused on understanding the capability of PROSPECT to sufficiently preserve volatile content in regolith throughout the sampling-analysis chain: from drilling to sealing of the ovens, until measurement of evolved gases in ProSPA’s ion-trap and magnetic sector mass spectrometers. PROSPECT’s ability to meet science requirements must persist for the range of possible volatile contents expected in near-surface regolith at landing sites in the lunar south polar region.

How to cite: Heather, D., Sefton-Nash, E., Fisackerly, R., Trautner, R., Barber, S., Reiss, P., Martin, D., and Houdou, B.: The ESA PROSPECT Payload for Luna27: Development Status, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-672, https://doi.org/10.5194/epsc2020-672, 2020.

Lunar impact flashes: first detection from the Observatory of Nice

Avdellidou⁽¹⁾,M. Delbo⁽¹⁾, E. Munaibari⁽¹⁾, R. Larson⁽²⁾, J. Vaubaillon⁽³⁾, P. Hayne⁽²⁾, D. Sheward⁽³⁾, A. Cook⁽³⁾

• (1)Laboratoire Lagrange, Observatoire de la Côte d’Azur, UCA, France
• (2)University of Colorado, USA
• (3)IMCCE, Observatoire de Paris, France
• (4)Aberystwyth University, UK

contact: chrysa.avdellidou@oca.eu

Abstract

We report the first lunar flash due to meteoroid impact observed by our team at Observatoire de la Côte d’Azur (OCA) in south France.

Introduction

Meteoroids impacting onto the lunar surface can produce very short bursts of light–commonly calledimpact flashes. Such flashes have been the subject of several lunar monitoring surveys over the last 20 years (1,2,3) for the purpose of determining the size frequency distribution of near-Earth objects in the cm–dm size range. The goal of our international team is to build a network of moderate telescopes that will survey the lunar surface for impact flashes and subsequently locate the produced impact craters. We have developed all the necessary algorithms in order to detect the flash events in real time during the observations, identify the selenographic coordinates, link the meteoroid to a parent meteoroid stream, measure the mass and size of the meteoroid (4) and discover the potential fresh lunar crater. Updates on the methodology is presented by the accompanying EPSC 2020 abstract of Munaibari & Larson et al. The description of the crater identification is presented by the accompanying EPSC 2020 abstract of Sheward et al.

First confirmed impact flash from OCA

On the night of May 27^th, 2020 at 20:48:49.420 UTC, we detected our first impact flash from the Observatoire de la Côte d’Azur (site of Mt. Gros). This is the first live impact observed for the project "Flash!", the first from the Observatoire de la Côte d’Azur and the first from all France by professional sites. The telescope used is a 16" MEADE coupled with a CMOS ASI ZWO 183mono camera. The frame rate was 20 fps and the frame integration time was 0.05 sec. The telescope was guiding on the lunar crescent using the lunar autoguider that we developed in the framework of the master course of MAUCA (University of Côte d’Azur).

Acknowledgements

This work was supported by the ProgrammeNational de Planetologie  (PNP), France  ofCNRS/INSU, co-funded by CNES, France and bythe program "Flash!" supported by Crédits Scientifiques Incitatifs (CSI), France of the UniversitéNice Sophia Antipolis. This work has made use ofdata from the European Space Agency (ESA) NELIOTA project. We thank the EUR Spectrum for supporting Mr. Munaibari with a 3-monthUCA Master Scholarship to perform this masterthesis.

 References

[1] J. L. Ortiz, et al.A&A,343: L57–L60, (1999).

[2] J. L. Ortiz, et al. Nature, 405:921–923, (2000).

[3] R. M. Suggs, et al.Icarus,238:23–36, (2014).

[4] C. Avdellidou & J. Vaubaillon.MNRAS, 484(4):5212–5222, (2019).

How to cite: Avdellidou, C., Delbo, M., Munaibari, E., Larson, R., Vaubaillon, J., Hayne, P., Sheward, D., and Cook, T.: Lunar impact flashes: first detection from the Observatory of Nice, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-744, https://doi.org/10.5194/epsc2020-744, 2020.

Performing radio astronomy observations from the Earth’s surface is plagued with interference issues. The Earth and its surrounding atmosphere, particularly our ionosphere, are massive sources of natural interference. There are also human sources of interference. There have been several studies attempting to solve the issues surrounding radio observations. One such solution is to find radio-quiet zones, such as the far side of the Moon. In his article "Farside explorer: unique science from a mission to the farside of the moon" David Mimoun states that the Moon is "the most radio-quiet environment in near-Earth space." [1] The far side of the Moon is insulated from Earth's various interference sources. This certainly makes it a great candidate for radio astronomy. [2][3]

Due to the rotation and orbiting speed of the Moon, the same side of the Moon is always facing Earth. However, the building of a radio antenna array on the Moon and operating it would be costly. Therefore, tests must be prepared on Earth in advance. These tests are performed with the EuroMoonMars project. Using the Radio Jove receiver with dipole antennae, Solar and Jovian observations will be performed. These observations can be compared with data from other radio telescopes and arrays. This would allow radio astronomy to be tested both as a concept and as a prediction tool for solar weather. Even though the Earth is protected by our atmosphere, the Earth is affected by solar weather. [4] The near side of the Moon will be affected by solar weather and this could be predicted and diagnosed by radio instruments. 

During the COVID-19 pandemic and lockdown, observations have been carried out in Bray, Ireland and at The European Space Technology and Research Centre (ESTEC) and Leiden in the Netherlands. These locations are all at similar latitudes. Further observations are planned in Iceland. The EuroMoonMars is launching the CHILL-ICE campaign in 2021 and radio observations will be an integral research topic. Experiments will be carried out to determine the angular response and efficiency of the apparatus in a volcanic region. The rest of the EuroMoonMars CHILL-ICE team deserve thanks for their support of these experiments.

The Earth-based apparatus contains a single dipole, the Radio Jove receiver and a laptop to receiver processed data. The experimental methods can be defined as follows: 

                            Graph 1: Data recorded in Radio Skypipe software, taken on the 15^th June 2020, during reported solar prominences.

References:

How to cite: Laffan Downes, E. and Foing, B.: Radio Astronomy from a Lunar Environment Precursor Tests , Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-799, https://doi.org/10.5194/epsc2020-799, 2020.

Abstract

During the 2019-01-21 lunar eclipse a lunar impact flash was observed by more than 20 observing sites, and two published estimates were made as to the location of the impact flash. In this work we present the preliminary results from the utilising PyNAPLE (Python NAC Automatic Pair Lunar Evaluator) with these coordinates in the search for the resultant impact crater. In total, 97 surface changes were detected, two of which being definite impact craters; however evidence suggests that they were formed during separate events to the 2019-01-21 impact.

Introduction

Lunar impact flashes been observed at least 600 times across both professional and amateur observation campaigns[1,2,3]. Despite this large amount of data, there are still unknowns when examining the relationship between the impact flash and the resultant impact crater. The most important unknown being the luminous efficiency, which determines the ratio of incoming kinetic energy converted to light, currently taken as between 10^-2 and 10^-4 [4]. Another unknown is to do with accuracy of crater scaling laws, which estimate the size of the formed impact crater but are derived from high energy impact tests, which become inaccurate for smaller impacts such as the most common lunar impacts [5].

In order to obtain ground truth data for refining of scaling laws, and further examination of luminous efficiency, PyNAPLE [6] is utilised to locate the resultant crater from hundreds of observed lunar impact flashes. The results discussed here are from a single search performed on the 2019-01-21 lunar impact flash, which coincided with the lunar eclipse and therefore had a number of analyses and location estimates performed [7,8].

Methods

Using images from the Lunar Reconnaissance Orbiter Narrow Angle Camera (LRO NAC), a temporal pair (a pair of 'before' and 'after' images) can be divided highlighting changes between the two images. This process requires a number of constraints to be met, such as illumination angles being within 10^o of each other, and being nadir pointing. This limit the number of pairs that can be formed for any location, especially as the events become more recent having less potential 'after' images.

Using PyNAPLE, an exhaustive search can be performed forming each temporal pair in an area around the event location. This allows the identification of new surface features formed between the temporal pair images, which with adequate coverage locates the crater formed during the impact.

The search for the 2019-01-21 crater was performed using literature values, and values calculated by AUGUR [9] (Table 1). Due to the lack of overlap between the coordinate estimates, a search area encompassing the coordinate ranges was used.

Table 1: Locations of the 2019-01-21 impact determined from observations of the impact flash.

Results and Intepretation

During PyNAPLEs ~350 computing hours search, 235 images were evaluated. After eliminating unsuitable images, this left 100 before and 30 after images. In total 108 temporal pairs were formed, and 97 confirmed surface changes identified (Fig. 1). The majority of these changes were small 'splodges' of darkened regolith due to impacts below the resolvable size for the LRO NAC, or ejecta deposits from nearby impacts. Two of the identified changes were clearly identifiable as impact craters (Fig. 2).