Noemí Pinilla, a researcher at the Florida Space Institute of the University of Central Florida, has a very close relationship with the Instituto de Astrofísica de Canrias (IAC). She studied astrophysics at the University of La Laguna (ULL) and after obtaining her doctorate she made the jump across the Atlantic to the NASA Ames Research Center as a postdoc. Now, as on previous occasions, she continues to collaborate with the IAC, to be specific in the preparation of a spectroscopic catalogue of asteroids, and studying the ices and the surfaces of the dwarf planets of the Solar System. Even though she comes here to complete a project, she always goes away with new ideas, probably to return soon to collaborate with her former colleagues from the Canary Islands.
By Elena Mora (IAC)
“The PRIMASS data base of primitive asteroids which Julia de León and I are directing is by now the most complete spectroscopic catalogue of families of the inner belt, where we have made the most extensive characterizations”
“The astonishing images which New Horizons gave us of the surface of Pluto confirm its high degree of activity and strengthens the hypothesis that the larger icy bodies may be hiding the keys to their sub-surface activity, and to the processes which transform their surfaces”
“We can expect that the contribution of the JWST to our knowledge of the Solar System, of its initial stages of formation, and of its subsequent evolution will be unequalled”
“There is another achievement which we have been after for years, and about which Hayabusha-II and OSIRIS-REX will have much to tell us: finding the organic molecules which may be related to the origin of life on Earth”
“The discoveries with highest impact are usually those which we don’t foresee, because they are unexpected, and they let us be more creative in our analysis”
Question: How does a girl from Asturias end up work in NASA? ¿And as a visiting researcher at the IAC?
Answer: Working for NASA was a case of having been well directed in my thesis research. Javier Licandro, a researcher at the IAC, and Humberto Campins, a researcher at the University of Central Florida, were my thesis supervisors, and during the nearly five years in which I was researcher under their guidance they did a great job of putting me in contact with leading researchers in planetary science, but also in encouraging me and helping me to present my work at international conferences. This made my work visible, but it also gave me the courage to get in touch with a group at the NASA Ames Research Center and to apply, with the support of the group, for one of the postdocs there. When I was competing for this, I guess the rest of the merit was in the research in my dissertation, and in the research project that I presented. It seems that both were sufficiently interesting to make the committee decide to fund me for two years as a postdoctoral fellow in a NASA center.
As for the IAC, I have never stopped being related to the Institute since I finished my degree at the University of La Laguna (ULL). Either directly or indirectly, I have always been involved in projects with IAC researchers, and here I can meet not only with my former thesis supervisor but also with a set of researchers and students who are grouped around him. I always come to finish a project, and in the end I leave with two or three new ideas to develop.
Q: Your collaboration with the IAC is within the framework of the Solar System group. In what are you collaborating, and with which people and teams are you working?
Answer: With Julia de León, an IAC researcher, I am leading a spectroscopic catalogue of primitive asteroids, “PRIMASS”. We have been using telescopes, among them the Gran Telescopio CANARIAS (GTC), and the Telescopio Nazionale Galileo (TNG), both at the Roque de los Muchachos Observatory, in Garafía (La Palma), for over five years now to study those rocky bodies whose surfaces are composed of silicates and organic compounds, the least processed materials in the asteroid belt. Our data base in by now the most complete as far as spectroscopy of families at the inner-belt is concerned (these are asteroids between the orbits of Mars and Jupiter), where we have made the most extensive characterization. We hope to maintain this collaboration for at least two more years, to be able to extend it to minor families, because these could be more processed by collisions and this would be noted on their surfaces.
With Javier Licandro and Vania Lorenzi, support astronomer at the TNG, we are focusing more on the study of ices within the Solar System. In recent years I have run a campaign to study the variations on the surface of Pluto, combining observations with the Spitzer Space Telescope, and with the William Herschel Telescope (WHT), of the Isaac Newton Group of Telescopes, also at the Roque de los Muchachos Observatory. In addition, we are continuing to study the surface variations on dwarf planets, which was the subject of Vania Lorenzi’s thesis. The amazing images which New Horizons gave us of the surface of Pluto confirmed its high degree of activity and strengthen the hypothesis that the larger icy bodies may hold the key to the activity below their surfaces, and to the processes of space weathering, such as collisions, high energy radiation, and the sublimation cycles of volatiles.
Q: In recent years you have been analyzing images taken with the IRAC infrared camera on the Spitzer satellite. How do you study them? What are you trying to find out with the data you obtain?
Answer: Spitzer is a space telescope, which gives us unique information about trans-Neptunian objects (TNO’s) because it observes at wavelengths which cannot be detected from the ground. It allowed us to measure the albedo of several dozens of TNOs for the first time, and using them we could estimate their sizes. My work is to analyze the colors of a couple of hundred TNO’s and Centaurs obtained with IRAC, the infrared camera on Spitzer.
This region of the spectrum is very interesting because many of the ices on the surfaces of the TNO’s have their fundamental absorptions at wavelengths longer than 2.5 microns. Analyzing the data base which I am studying allows us to begin to formulate a scheme for the composition of the TNO’s which is much more accurate than what we can obtain from the visible and the near infrared data. For example, we can differentiate between organic compounds and amorphous silicates and we can detect nitrogen and carbon monoxide. These volatile ices are present on the surface of Pluton, (the most studied dwarf planet) but they have not been detected on other large TNO’s such as Eris, Makemake, Haumea, or Quaoar.
This analysis is very important as a starting point for the James Webb Space Telescope (JWST), NASA’s future infrared space telescope, which is in its final assembly stage, undergoing cryogenic testing, and it is crucial for selecting the most interesting objects, which will test the capacity of its on-board instruments.
Q: At the present time you are leading the project “Preparing for James Webb Space Telescope: Completing the IRAC Legacy in the Kuiper Belt”. What is this project about?
Answer: Well, just during this past year I have been devoting time to studying the scientific exploitation of the JWST for analyzing the minor bodies of the Solar System. This telescope will be launched in autumn 2018. For one year I have worked closely with those who are integrating the different instruments (NIRCam, NIRSpec y MIRI) to identify the most interesting scientific questions, those which only the JWST will be able to resolve. Next year, I will lead a proposal for the ERS (Early Release Science). These projects, which will be carried out in time granted by the telescope director, are intended to give the planetary science community at “time zero” (that is to say without a time buffer of data ownership) the most useful information, to resolve scientific questions which have had no answers until now, and also to test the optimal capacity of the on-board instrumentation.
Q: One could say that the future JWST will be the “big brother” of Spitzer, and that it will mean a revolution in the infrared exploration of space. What objects and phenomena can we study at these wavelengths? What will the JWST be able to observe which Spitzer’s technology cannot reach?
Answer: It seems a good definition to me, if you consider its size, but we could also call it the “little brother” because in a way it is following the path opened up by Spitzer, in orbit since 2003, and also by the Hubble Space Telescope, in orbit since 1990
The JWST has a mirror of diameter 6.6 meters, much bigger than the Hubble, and an image resolution much better than Spitzer. It will be able to observe very faint objects such as galaxies at high redshift, that is to say very distant, which is the key to understanding the formation of the first galaxies and the first bright objects.
It will also be able to observe other solar systems, which are forming. This has driven the capabilities of the JWST towards different modes of observation, from the possibility of observing the reflected light from giant planets of Jupiter type, to being able to observe them during the early stages of their formation when they were hotter. For all of these observations it will be very useful the coronographic mode, to cut out the light from the central star. But also among the observing modes there has been specific attention to those required to observe the transits of planets around their stars.
As for studies of our own Solar System the most attractive feature of the telescope is that it has been designed to observe objects that are moving on the sky, which is crucial for asteroids and TNO’s. Another of its most attractive features is its ability to perform spectroscopy in the infrared of a large number of faint objects for which we don’t yet have this information, and also its large set of filters for photometric observations. It will be easy to find a good combination to detect the different materials on their surfaces. The large wavelength rage cover by JWST, optimized to observe between 2 and 28 microns, is also a major advance compared to previous telescopes. With all of this we can expect that the contribution of the JWST to our knowledge of the Solar System, of the early phases in its formation and of its subsequent evolution will be unequalled.
Q: During this year’s Winter School of Astrophysics, we were visited by many experts in Solar System exploration. All of them were convinced that this is a special epoch for space exploration of our planetary system, and that soon we will make great discoveries. What do you think one of those discoveries could be?
Answer: At the moment Planet X (for “unknown”) is a hot topic. (I like the name because it reminds me of the X on pirates’ treasure maps!). If it really exists, as suggested by the model of Brown and Batygin, finding it would be a great event, and it would force the dynamicists to revise their models of the origin and the evolution of the Solar System to include a planet that their models did not predict. But in some way, this search is very similar to that for Neptune in its day, or for Pluto, so in that respect is may not be so novel.
There is another finding that we have been after for years, and about which Hayabusha-II and OSIRIS-Rex will have much to tell, this is to find organic molecules which may be related to the origin of life on Earth. I am talking about an extraterrestrial origin, in which the seed of life might have come from outside, on a comet or an asteroid. There has been much theorizing about this, but we still need to find the traces which relate it to the presently know primitive material.
Finally, there is something to keep when it comes to discoveries, those with greatest impact are usually those which we do not foresee, because they are unexpected, and because they let us be more creative in our analyses.