Tuesday, 31 March 2015

Many Small Nuggets from the 46th Lunar and Planetary Science Conference

Science talk at LPSC 2015.
I was in the room, but I don't think I'm in this picture.
Image credit:  Lunar and Planetary Institute. 

This year's Lunar and Planetary Science Conference (LPSC) was fabulous. I went as an independent researcher and was pleased to see that this is no longer frowned upon like it used to be in the past. Times are tough and budgets are tight. Many scientist are looking at alternate funding models to pay for their research. So, it was wonderful to get a chance to compare notes on this front.

I also was an independent microblogger this year. For the past three years, LPSC organizers have recruited conference attendees to write short blurbs about the session talks on social media. I didn't join the official microblogging crew, but continued to post to Google+ on my own terms - I wanted to reduce the pressure I put on myself.

And just like last time, I am reproducing my entire complement of LPSC microblogs here on the Planetary Geo Log. Don't feel the need to read it all at once, but rather savour a few small nuggets at a time. I hope to write up some of these in future blogs, so keep an eye out.

Sunday March 15, 2015
1)  I am at the Lunar and Planetary Science Conference again this year and will be microblogging about it. I hope you enjoy.....

2)  The talks at Sunday's session of Microsymposium 56 were really good! Some highlights below:
     - Ejecta from the Moon-forming impact may have reached the asteroids at very high velocities, producing melts that retain a signature of the event.
     - The Procellarum basin may be a palimpsest, formed in a warm crust and mantle.
     - A Procellarum-forming impact would have melted the underlying mantle to the core and distorted the crust at the antipode, allowing later melts to migrate to the surface.
     - The South Pole-Aitken basin may have precipitated mantle melting and also distorted the the crust at the antipode, allowing melts to come to the surface in the Procellarum region.
     - Early lunar impacts may have formed before the overturn of the olivine cumulate layer in the mantle, explaining why we see so little evidence of olivine on the surface. Alternatively, the composition of the mantle may be heterogeneous.
     - Modelling of crustal relaxation for the lunar basins suggests they must have formed when the crust was warm, which is too early in the Moon's history to be consistent with a late heavy bombardment.
     - Modelling of Orientale and seismic studies of the Chixulub crater show that outer rings of multi-ring basins are associated with multiple faults (some listric) that extend all the way to the Moho.

3)  The LRO Data Users Workshop took place on Sunday before the LPSC. Some very useful information on how to access and work with the LRO data was presented. Slides from the individual talks can be downloaded from the workshop website.

4) An impromptu demonstration of the Lunar Mapping and Modelling Portal (pub.lmmp.nasa.gov/LMMPUI/LMMP_CLIENT/LMMP.html) was presented at the end of the LRO Data Users Workshop. This tool lets you view a variety of lunar data layers, all registered together.
     I suggested that the ability to do math between the layers would be a very useful addition to the tools and the presenters seemed very receptive to this idea. Maybe that functionality will be added in the future.

Monday March 16, 2015
1)  The Next Generation Lunar Scientists and Engineers panel on tips and strategies for writing successful scientific papers was very informative. The best tips (in my humble opinion) included:
     - Start with your tables and figures and write around them - use them as your outline.
     - If you are having writer's block, start writing your figure captions.
     - Writing is a two step process: dump your thoughts, then word-smith. If you are word-smithing before you have finished dumping your thoughts, you can loose your train of thought or polish something that doesn't really fit anyway, and so end up wasting lots of time.
     - Make sure your paper has only one major take-away message, since that is all that most people will take way.
     - Have your paper end by outlining the next steps; this can be helpful when applying for grants.
     - Reviewers' comments aren't absolute; you can rebut them, preferably with evidence, when you write your response.
     - Rejections often have more to do with timing - the editor doesn't think you can address the reviewers' comments fast enough for their schedule. Unless the editor encourages you to submit this paper to other  journals, consider this an opportunity to edit and resubmit to the same journal.

2)  Overheard at the Students' Reception on Monday:
"I play the stock market, because I want to be a scientist, but I also want to live in a nice house."
... We need to pay our scientists more.      

Tuesday March 17, 2015
1)  Dr. Stuart Robbins gave a fabulous talk explaining the issues with current crater chronology techniques (i.e. figuring out the age of a surface by counting craters). His talk included some amazing animations of plots (of all things) that really helped me to understand some aspects of crater dating that I hadn't before. He's shared these animations with me and I will be posting them on my blog in the near future. Stay tuned.

2)  Using simulations, Dr. Carolyn van der Bogert showed that the crater count-determined model age of a surface depends on the size of your count area. For areas that are less than 100 square kilometers in size, the model age can be incorrect, with smaller areas giving younger ages. Caution should be used when determining the age of very small areas, and multiple regions of the same unit should be aggregated to provide counts over a larger area.

Wednesday March 18, 2015
1) LEAG Town Hall Summary  
     - Planning for a "New Views of the Moon II" is underway. Be ready to contribute to this upcoming volume (whose name is still to be determined). Contributions can also form the basis for white papers in the next decadal survey.
     - Contact your congressman about keeping LRO alive. The Planetary Society  is drafting a letter. Use this as a template for your correspondence, but personalize you letter, because studies show a personalized letter has much more impact than a form letter.
     - The next SSERVI Exploration Science Forum is this July 21-23. There will be talks streamed on the web. (http://nesf2015.arc.nasa.gov/)

2) Dr. Paul Lucey is talking about small lunar craters in the South Pole-Aitken basin. Except he keeps talking about craters in the SPA, pronouncing it "spaa" instead of "es-pee-ay", and all I can think about is getting a massage.
      Okay, I need to add that he found that small craters in SPA were almost exclusively noritic in compositions, which has implications for the composition of the mantle under SPA.

3) Dr. S. Lawrence pointed out that GRAIL lunar gravity data does not support the presence of a basin in the Australe region of the Moon.
4) Just finished giving my talk on the complexity of cryptomaria in the Mare Humorum area of the Moon. Whew! Now I can get back to microblogging.

Thursday March 19, 2015

1) Dr. Aileen Yingst used the MAHLI camera on the Mars Curiosity rover to show that fine grained deposits in Gale crater were formed by settling from suspension. The suspension medium is most likely water, because there are no aeolian features present.
     Dr. Yingst and I talk about this some more later and further concluded that the larger grains that can be seen interspersed among the fine grains could not have been carried by wind processes, again supporting the hypothesis that these materials were deposition by settling in water.

2) Dr. Rebecca Ghent looked at radar data of the lunar regolith and found that rocks on the surface break down and disappear within about 1 billion years. Rocks within the regolith, on the other hand, persist for long periods of time, well beyond their brethren on the surface.

3) A big thank you to Scott at the JMARS booth, who took time during Thursday's poster session to try and solve my JMARS issues.

Friday March 20, 2015
1) Dr. H. Nekvasil conducted experiments that show how crystallization of plagioclase under high pressures can make the plagioclase more anorthitic with cooling. At low pressures, cooling plagioclase becomes more albite-rich, making it difficult to explain the high anorthite content of the lunar highlands crust. Dr. Nekbasil's work suggests the highland plagioclases could have cooled under higher pressures at depth in the lunar mantle and then been transported to the surface.

2)  Dr. Pete Schultz gave an amazing talk about the impact that formed South Pole-Aitken (SPA) basin. First he showed spectacular high speed movies of experimental impacts into glass spheres, which demonstrate the disruption and damage that occurs at the antipode of the impact site. These also showed that the antipode of the impact site is not the same as the antipode of the crater for oblique impacts. Next, Dr. Spudis evaluated geological features of SPA , showing that SPA is an oblique impact and that the antipode of the impact site (but not the crater) coincides with the centre of a system of tectonic features related to Procellarum. He thus concludes that the SPA impact would have disrupted the crust under Procellarum, allowing significant melts to form and migrate into the crust. These melts would have differentiated, forming a KREEP layer that was later exposed by the Imbrium impact event. Wow!

3) One of the themes for the Moon at LPSC this year has been the composition of the lunar mantle. Considering the variety of studies and findings, it is clear that we really don't know what the lunar mantle is made of.

4) Zack Morse is doing some great work mapping the ejecta of Orientale basin on the Moon. This impact has been mapped before, but the last extensive work on this was in 1977. Zack is re-visiting these deposits using more recent data sets like the LROC WAC and NAC images.

5) Dr. P. Boehnke pointed out that only about 50% of all lunar impact samples were heated to temperatures hot enough to reset their Ar/Ar ratios during the impact that formed them. Thus, about 50% of Ar/Ar dates from these samples will show ages that are older than the impact event. This needs to be considered.

6) That's it. The last talk has been given. The last drink at the bar has been drunk. And the last goodbyes with old friends have been said. Farewell #LPSC2015. You were a great conference for me.
Till next year....