[English]

Transient Lunar Phenomena

(supervisor: Tony Cook)

Nature of project: data analysis, theory

Available to full-time physicists or joint students.

Project description and methodology

Over the last thousand years there have been approximately three thousand reports (mostly through telescopes) of temporary glows, flashes, colourations, and obscurations of detail on the Moon. Unfortunately the Moon is pretty much a geologically dead object and it is difficult to explain phenomena that could occur on, or above the surface that could be seen from the Earth from 400 thousand km away. If we take the solar constant illuminating the Moon to be 1400 W/m^2 and 12% of this gets reflected (by the dark lunar soil) back to Earth i.e. 168 W/m^2 and assume that we can detect >5% variations, then we need some mechanism to radiate ~8 W/m^2 in order to be seen from the Earth on the dayside Moon. On the night side of the Moon, we would need a radiance of just 0.1 W/m^2 to be detected against reflected Earthshine.

Theories to explain TLP have included: optical emission and absorption from out-gassing, optical scattering from electrostatically levitated dust particles, tribolectric discharge between electrostatically levitated dust particles in a rarefied gas, optical fluorescence, and impact events. Although rare (just a few per year) it is even possible that shallow magnitude 3-5 Moon quakes, could agitate and charge up dust particles initiating some of the dust particle cloud explanations above; shallow Moon quakes, although less powerful than the strongest of Earth quakes, can be sustained for several tens of minutes unlike their counterparts on Earth.

Your task in this project is to investigate the statistics of TLP reports in order to see which theories are still supported by the observational evidence.

A successful project will develop beyond the above in one/some of the following directions:
For comparison we have a control dataset of approximately 30 thousand observational reports where no TLP have been seen - referred to as Observational Nulls. So you might want to look into four (or more) of the following:

1) Do TLP correlate with geo-spatial aspects of the Moon e.g. mare edges, young ray craters, faults, moon quake locations, area of very young surfaces etc

2) Do TLP correlate with time dependent factors e.g. maximum tidal stress, meteor showers etc

3) Do TLP correlate with solar wind events i.e. is there a preferred solar wind pressure, temperatre, density (or rate of change of these) when they occur more often?

4) Do TLP correlate with the altitude of the Sun above the lunar horizon?

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: Investigate observing effects to see if they can explain some TLP reports e.g.

1) The altitude of the Moon above the horizon of the observer.

2) Telescope type and aperture.

3) Try modelling atmospheric spectral disperion and chromatic aberration on images to see if you can put colours where observers have claimed to have seen them on craters on the Moon

Initial literature for students:

  1. Crotts, A.P.S. (2008) Lunar Outgassing, Transient Phenomena, and the Return to the Moon. I. Existing Data, The Astrophysical Journal, Volume 687(1), pp 692-705.
  2. Dollfus, A (2000). Langrenus: Transient Illuminations on the Moon.. Icarus 146 (2), pp 430-443
  3. Zito, R.R. (1989) A new mechanism for lunar transient phenomena, Icarus vol. 82, Dec. 1989, pp. 419-422
  4. Geake, J. E.; Mills, A. A. (1977) Possible physical processes causing transient lunar events. Physics of the Earth and Planetary Interiors, 14, pp 299-320.

Novelty, degree of difficulty and amount of assistance required

The project has a strong research flavour, and the student(s) should be keen on astronomy and have a good understanding of statistics. Although no observing is planned, if the students wish, they can do some time lapse imaging of the lunar surface, to appreciate the problems of TLP observing. The supervisor will be available to answer questions on all these aspects, should it be necessary.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Assess which statistical aspects of TLP to stidyend of November
Telescope training if neededChristmas
First two statistcial analysis tasks completedend of February
Final two main statistical tasks completed along with any other studies you wish to domid-March

Students taking this project will have to submit a full risk assessment form