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Amara Graps Personal/Professional Page

UNDER CONSTRUCTION

I. A large area of my research which stems from my PhD thesis is the dynamics and charging of interplanetary dust. The contexts in which I'm presently focusing: 1) Saturn’s magnetosphere, 2) Asteroid surface regoliths, and 3) comet dust electrostatic fragmentation.
 
1) Saturn's magnetosphere. What a rich area of dust studies. Some questions I'm trying to answer: Can E-Ring Dust impacts alter the surfaces of the Saturnian moons? How long have Enceladus' plumes been active? Since the E-ring needs to be continually replenished due to the short estimated lifetime of its particles, and we know that the dust particles in the plume are adequate to maintain the E-ring, then the deep, interior source of the Enceladus' plumes must be vast. Is there any way to determine a time-history of Enceladus' plumes today? Yes, with an examination of the surfaces of Saturn's_other_ mid-sized icy moons.

2) Electrostatic Dust Charging on Asteroid Surfaces. A number of asteroid missions in development or already flying demonstrate some of JAXA's, NASA's and ESA's space mission foci with intriguing images of the asteroid surfaces. Landslides, ponds, areas where regolith / dust might have been transported. How? Electrostatic forces have been hypothesized to play an important role on the surfaces of asteroids, and have been specifically invoked as one means by which small grains can be transported across a body’s surface. How dynamic is an asteroid's dusty electrostatic environment? What makes an asteroid an attractive dust laboratory, is their fine regolith embedded in the interplanetary plasma and illuminated by solar photons. As a prelude to this study is the necessity to comb, catalog, and calculate regolith properties from dozens of asteroids in order to help researchers and mission designers prepare for the conditions on the surface of the asteroid. My Asteroid Regolith Database project is geared towards that. The methodology has been scoped out and vetted and presented publicly (ACM 2014). Now it needs student help to build its contents.

3) Comet Dust Electrostatic Fragmentation. After ten years of mission development and ten years of travel and 2.5 years of hibernation, ESA’s Rosetta space mission to comet 67P / Churyumov-Gerasimenko is in orbit around the comet and in full data acquisition mode with its 22 scientific instruments working to understand our Solar System’s -- and by extension, our human’s --   origins. As of this time in middle February 2015, vast amounts of data that describe its topology, surface, chemistry, interaction with the solar wind, coma particulates and more has already been acquired with preliminary results presented and published.  Physical characteristics of the comet nucleus show it to have a mass of 1013 kg and a bulk density of ~470 kg/m3 (similar to cork, wood, or aerogel). The low mass and density values imply a relatively fluffy nature, with a porosity of 70 to 80% (Sierks et al., 2015). With such bulk properties perhaps scaled to its finest particulates: the dust grains, results (AGU, 2014) from the COSIMA and MIDAS instruments describe a population of “fluffy aggregate” particles (MIDAS) and “rubble pile” particles (COSIMA) that have a low cohesion and which can break apart easily. The physical process proposed for such fragmentation is the topic of this study: Electrostatic Fragmentation Analysis which was submitted in the C-DUST proposal to the European Commission's Horizon 2020 COMPET-5 program on April 8, 2015 (as University of Latvia Lead Scientist).

II. Tackling a new research area: What is the Origin of Earth’s Water?

This topic is in transition from a 10-year-old hobby interest to a research project. The origin of water on Earth is one of the most puzzling enigmas in the planetary sciences. Our planet that spawned our watery origins presently carries enough surface water in vapor or liquid form to cover the entire planet to a depth of about 3 km. Earth has substantially more water than scientists would expect to find at 1 A.U.  Other compounds and elements also readily vaporize at Earth's distance. Typical protoplanetary disk models and meteorite data suggest that the 1 A.U. zone where the Earth formed was too hot for water to be directly incorporated in local planetesimals.  Or was it? How well can the endogenic theories for water production on Earth compare against the exogenic theories of water delivery?  Dating solar system objects in particular, can address the questions: Which objects brought the water and in what quantity and at what time?  Do the dates provided by geochronology on Earth samples, lunar samples, Martian samples confirm the Nice model? Do those dates support the modification to the Late Heavy Bombardment, the so-called:  Great Archean Bombardment. 

Early in 2014, the Herschel Space Observatory made the significant discovery of water vapor around Ceres (Küppers, M., et al., 2014. ).  In three observing epochs from October 2012 to March 2013, the data showed a strong absorption line against the thermal background at the water ground-state: 0.54 mm wavelength.  This line is consistent with water vapor confined close to Ceres. This detection points to ways of establishing asteroids as a potentially important source for delivering water to Earth. The phenomenon of active water sublimation on Ceres provides the opportunity to identify its source region, and study the sublimation mechanisms. In turn, a study of Ceres’ surface water has important implications for the energy source and budget on Ceres, which are essential for evaluating the astrobiological significance of this largest water reservoir in the inner Solar System beyond Earth. With this in mind, my University of Latvia PhD student: Karina Šķirmante, has planned observational sessions of OH maser emission lines in IEEE L-band with the 32m radio telescope of Ventspils International Centre of Radio Astronomy to clarify the following questions, which examine the physical characteristics of Ceres as a water-bearing dwarf-planet (large asteroid): "what constraints can the OH measurements provide to the mechanism for which the water emerges and disappears on Ceres’ surface, and for how that body formed?”

III. Supporting the New Space Community in Latvia.

I'm living in Latvia as currently the only planetary scientist. Despite the country's minimal planetary research efforts, there are pockets of enthusiastic Latvian industry and education and public space activities. These pockets were enough to convince the policy makers (Cabinet of Ministers) that joining the European Space Agency is a valuable step for the country's development, now Latvia is a new ESA participating member country in 2015. My aim is to help coordinate the pockets of space enthusiasts and to keep the Latvian space dream alive. I'm one of the founding members of the Latvian Space Bureau, a non-governmental group which meets quasi-regularly (~once per month) and communicates via FB and email to inform each other of funding opportunities, space activities, project activities seeking partners and students. Contact me if you wish to be on the overseas (konteur.com server) Latvian Space Bureau mailing list.

IV. Planetary Climate Detectives. A funded (starting in September 2015) Do-It-Yourself Climatology Project for ~8-13 year olds.

As part of Europlanet 2020 and the with my University of Latvia/ Institute of Astronomy affiliation, I will develop a a kit for students to build Arduino-based climate monitors, which students will use to collect data and upload to a database within an online platform. Scientists on planetary analogue field trips supported through Europlanet's adjoining TA programme, will gather comparative climate data from the field sites and share this via the online platform. I will write activity plans and learning resources around the aspects of the project (e.g. climate, weather, seasons, the movement of the sun during the day, position of planets within the solar system, conditions for life etc), which will be made available via the online platform. The platform will include a Wiki where students can share data, ideas and activities. The educational activities will be piloted with the aid of a core group of European schools and science centres in the first phase. Following evaluation and adjustments, the kits will be disseminated via MakerSpaces, Science Centres, teacher training groups and other partner networks. The parts list and links to suppliers will be listed on the online platform, in order to reach a wider audience. Scientists participating in the field trips will be encouraged to carry out at least one live social media event (e.g. live-streaming experiments, Twitter Q&A etc) during their mission, as well as participating before and/or after their mission in link-ups with schools to discuss field results, data gathered by schools and careers in planetary science. 

V. And finally some great software! PlanLet-Py: A Wavelet Library for Astronomers

I was a scientific programmer for 18 years for ten different astronomy teams before I jumped back to school and earned my PhD. Let's say that I have a passionate interest in providing great tools for astronomers, if I have the resources to do so. PlanLet-Py is the new name of an old wavelet library currently in an old beta form in IDL and the result of an unsuccessful 2009 NASA AISR proposal. I wish to convert the hundreds of modules from IDL to Python I am looking for funding source(s) for that. With that in mind, I prepared a work package for which was submitted in the CATNAP proposal to the European Commission's Horizon 2020 COMPET-5 program on April 8, 2015 (as University of Latvia Lead Scientist).

What are wavelets? Wavelets are functions that are used in representing data or other functions. They are useful to approximate data contained neatly in finite domains, and because Fourier basis functions stretch to infinity, wavelets therefore have advantages over Fourier methods when analyzing data with sharp discontinuities, sharp spikes, and point sources; data most often seen in the astronomical community. The use of IDL is pervasive throughout the astronomical community, however, complete public domain IDL wavelet libraries for astronomers to perform a wide range of wavelet analysis do not exist presently. This project aims to remedy that. This project, PlanLet-Py will provide to astronomers the most sophisticated in digital signal processing techniques to assist in their data analysis. It will be a free and easily-available library of wavelet functions expected to be useful for astronomers, that will include a command-line accessibility for pipe-line processing and a User Manual with many real-world examples. One new, spherical wavelet, a HEALPix wavelet, which is new in the extended wavelet community, will be included in PlanLet-Py.

 
 

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