NASA Scientist Amy Mainzer Searches Beyond the Sky for Interesting Questions

Dr. Amy Mainzer

The night sky and its seemingly limitless expanse of stars, asteroids, satellites, planets, galaxies and distant objects undiscovered has been the source of inspiration for writers, artists, scientists and most recently the wildly popular film ‘Gravity’. I recently had the opportunity to speak with NASA scientist Dr. Amy Mainzer, a Deputy Project Scientist at NASA’s Jet Propulsion Laboratory who was recently included in a 60 Minutes segment on detecting asteroids. Ms. Mainzer, who earned a B.S. in Physics with honors from Stanford University, an M.S. in Astronomy from the California Institute of Technology and a Ph.D. in Astronomy from the University of California, Los Angeles, is the latest profile in our popular Women in Science, Technology, Engineering and Math (STEM) series of articles.

James Morehead: What inspired your love for science, and astronomy in particular?

Dr. Amy Mainzer: “When I was a little kid, five or six, I always liked playing outside, and exploring what was going on in nature. When I was in first grade my parents bought me a kids book on Greek myths, Perseus, Andromeda, all that good stuff. I remember going to the library and looking in an encyclopedia to learn more and found there were multiple definitions for many of these mythological figures, that Perseus and Andromeda are also constellations, and that struck a chord. I started out learning about mythological characters and fell in love with astronomy!

“That sparked my imagination, and left me wanting to learn more about the universe, the space around us. Where I lived, in Akron, Ohio, there wasn’t access to a lot of information on astronomy, so I read everything I could in the library. Before the Internet, information was really hard to come by, especially up-to-date information about space missions. I remember clinging to the newspaper and watching anything I could find on TV about Voyager, the mission to the planets.

Morehead: I was speaking with a friend of the family recently, a UC Berkeley student who is pursuing science, and he described middle school science as “the history of science” vs. true exploratory science. What does it mean to be a scientist and is the reality different from the experience of many students in middle and high school?

Mainzer: “A real career in science is nothing like the classes in school and unfortunately that’s how we lose a lot of people. A lot of potential scientists get turned off because they think being a scientist is like the classes that they take, which can be very focused on memorizing lists of long words that don’t convey a concept or teach your brain how to think; real science isn’t like that at all. Real science is about asking interesting questions and figuring out how can we solve them. Real functioning life as a researcher has so little to do with the memorization of facts and lists that it’s surprising we still teach that way.”

Morehead: Why are computers and knowing how to code important for scientists?

Dr. Mainzer in a clean room

Mainzer: “If science is the way the universe works then math, and in particular scientific programming, is the language we all speak. Use of the computer is probably the single most important technological advancement that’s driving astronomy research. Calculations that used to take thousands and thousands of hours by hand can now be done in seconds, and the impact on astronomy has been profound. We can now run simulations that would have been completely and utterly impossible before. We filter through mega-pixel images in a fraction of the time that it would have taken before.

“While the human eye is a great tool, when looking at the night sky we really want electronic images; and what are electronic images but huge arrays of numbers. The human eye can’t possibly process thousands of images, searching for an interesting object. You’ve got to teach a computer to do the work because there’s no way your brain can do it. We spend a lot of our time training the computer to take over tasks that are too time consuming for humans.

“One thing that human brains are really good at is pattern recognition and associations. For example, if I say the word ‘pineapple’ in the time that it takes me to say the word you’ve probably conjured up a dozen images or memories of pineapples, or things that have to do with the word pineapples. Our brains are really poor at multiple, repetitive computations, and that’s what computers are used for. Nowadays we rely on computers to do repetitive calculations, such as grinding through huge volumes of pixels to identify data that has particular characteristics, and then we use our our human brains to interpret the results.

“The computer has changed everything for astronomy and science as a whole.”

Morehead: When I stare into the night sky the scope and scale of the universe is overwhelming. Given the infinite scope of the problems you can pursue, how do you decide which questions to ask and explore?

Mainzer: “This is one of the things that is so wonderful about science and I wish there were a way to teach it in the classroom. Good scientists figure out what problems are interesting and what problems they can do something about.

“There are a number of things that have been fun in my career and one of the things that surprised me is that I really enjoy building the sensors and devices used in experiments. I like designing experiments, building the devices needed to test a hypothesis, interpreting the results and figuring out what they mean. I’ve spent a lot of time in my career building the telescopes and cameras that are sent into space to take measurements.

Spitzer Space Telescope (source: CalTech)

“One of the things I was really proud to work on was Spitzer, the infrared twin to the Hubble space telescope. While Hubble mostly uses visible light, Spitzer goes far into the infrared spectrum, or wavelengths that human beings by and large perceive as heat. While we don’t see infrared light, we feel it. When something feels warm on your skin, when you put your hand in the sun, what you are mostly feeling is infrared radiation from the sun interacting with your skin.

“The Spitzer space telescope ‘sees’ infrared light rays and one of the first things you have to figure out with a telescope is how to make sure it’s pointed in the right direction. I built a small sensor for Spitzer, the fine guidance sensor, which tells the telescope if it’s pointing in the right direction. Spitzer launched in 2003 and has been used every day for the last ten years. I’m very proud of the sensor I built because it’s enabled Spitzer to do all kinds of different science, everything from studying exoplanets to exploring the most distant galaxies.

“Spitzer is in deep space and is now very far away from the earth, it’s actually just about as far away from the earth, as the earth is from the sun. The telescope doesn’t orbit the earth, it orbits the sun, and is in what we call a heliocentric orbit. Spitzer has been drifting away from the earth for the last ten years to make measurements in deep space.

“Infrared space telescopes like Spitzer need to be in space, far away from the earth which is very warm, to detect the heat coming from astronomical objects. It’s like trying to see stars in the middle of bright daylight and blue sky, except with infrared radiation the earth is too ‘bright’ all times of the day or night. The best way to get away from the infrared radiation of the earth is to get off the earth and travel into deep space where it is cold.”

Morehead: What things has Spitzer detected that were surprising or that reinforced existing theories about the universe?

Mainzer: “One of the things that has been most remarkable for me personally and extremely gratifying as an astronomer is that Spitzer has been able to detect and analyze the atmospheres of exoplanets, been able to give us a clue as to what these exoplanets are made from, and what conditions would be like on some of these alien worlds. To me that is an incredible discovery because Spitzer was not originally designed for that purpose, and it turns out that the fine guidance sensor is an important part of being able to make those measurements.

“I’m really proud because every time a new finding comes out that’s a little piece of me out there.”

Morehead: Regarding the asteroid named after you, how did that come to be?

Dr. Mainzer and WISE

Mainzer: “That’s related to my latest project, which I’m also really excited about, the Wide-Field Infrared Survey Explorer (WISE) which is part of the NEOWISE Program to search for asteroids that are near the earth (near earth objects). We’ve used this telescope to detect, discover and characterize asteroids that get close to the earth. By detecting the infrared radiation of the asteroids we’re seeing the heat that they emit. This is important because the problem with reflected sunlight is that when you see an object in space you don’t really know what it is made out of, and you don’t know how far away it is initially.

“When we see reflected light, we are seeing light bouncing off the surface which is a combination of the size of the object as well as how shiny or dark the surface is. A very reflective surface, like a freshly paved sidewalk tile, will be very bright in the sun, whereas something that is very dark, like a piece of coal, will be fainter and harder to see. With a heat-sensing telescope, the surface reflectivity – whether or not the surface is bright or dark – doesn’t matter. It’s the heat that you are sensing and that doesn’t depend on the reflectivity.

“Sensing heat has two important benefits: one, we can now see dark asteroids and two, we can determine the size of asteroids, and therefore the hazard they may pose to the earth.”

Morehead: What advice do you have for middle and high school students that are interested in pursuing science, but are having trouble seeing a connection between what they are learning in school and what you’ve described as the actual work of a scientist?

Mainzer: “The thing you need most to be a good scientist is curiosity. To be curious about the world around you, to be interested in things, asking questions about how things work. Even asking ‘why is the sky blue?’ is a profound question. It turns out that the answers are really interesting. Keep asking questions, even for things that you think you understand.

“Even though sometimes in class it seems like a lot of memorization, that isn’t life as a scientist. Scientists ask questions and try to figure out how things work, and I couldn’t imagine doing anything else. The thing I love the most about science is it’s really about appreciating nature and trying to understand more about the world around us.”