Science Q&A with Noemi Pinilla-Alonso, NASA astrophysics researcher
Noemi Pinilla-Alonso grew up in a city called Oviedo, in northern Spain, and specialized in astronomy and astrophysics at the University of La Laguna, Santa Cruz de Tenerife, Spain. As a graduate student, she worked at El Instituto de Astrofisica de Canarias and the International Observatory of El Roque de los Muchachos also in the Canary Islands. In 2009, she won a NASA post doctoral fellowship.
You are the co-author of a research paper titled, "Water ice and organics on the surface of asteroid 24 Themis," recently published in the British-American scientific journal Nature. What was the discovery, and why was it so important?
This was an amazing discovery. We thought asteroid 24 Themis was orbiting the sun too closely (~3.1 AU) to keep ice on the surface. We really expected ice to evaporate quickly into space from the surfaces of asteroids. We were looking for traces of water, such as hydrated silicates, which have been found on other asteroids.
What we found was a paper-thin layer of water ice, covering the entire asteroid. This discovery means there must be a mechanism replenishing the water.
Is it possible to estimate how much water is in the asteroid?
It is not possible from our observations to estimate the size of the reservoir. We can only see the coating on the surface, which is microns thick. We are not sure of the mechanism that is replenishing it, although we make suggestions in the paper. This will be a goal of future studies.
Since water and organics were found on the asteroid, could it support simple life-forms?
Possibly. It is widely accepted that asteroids and comets may have brought the building blocks of life to Earth. The conditions in asteroids are not favorable for life; however, studying primitive asteroids as "fertilizers" for life, may become an area of greater interest to astrobiologists.
What type of laboratory experiment did you perform to make your discovery?
My doctoral thesis was on icy objects in the solar system. I used models containing mixtures of icy materials to study their surface compositions. My contribution to this paper was modeling and interpretation; I am the group’s modeling expert.
In the case of 24 Themis, we produced a synthetic spectrum with a band around 3.1, which was similar to the observed spectrum. We were surprised to find our synthetic and observed spectra matched the spectra for water ice, and even more surprised to find our spectra matched a residue that could be complex organic material: this is an amazing result!
What inspired you to work for NASA?
I received a NASA postdoctoral fellowship to study the nature of organic materials in the solar system. At NASA, I work with a small group of planetary scientists who study minor bodies in the solar system, such as asteroids, trans-neptunian objects, dwarf planets and icy satellites. These objects are growing in importance to our understanding of the origin and evolutionary history of the solar system.
From Spain, working for NASA was a dream too big to think it could come true. NASA is known all across the world as a reference for astrophysical research. I was inspired by NASA’s high-level scientists, and the opportunity to broaden my knowledge by talking and working with them.
Ruth Dasso Marlaire
Ames Research Center, Moffett Field, Calif.