cuttingedge • goddard’s emerging technologies
Volume 17 • Issue 4 • Summer 2021
The project is currently receiving Internal Research and Development (IRAD) funding to accomplish the necessary preliminary work on orbit, optics, artificial intelligence and science arguments as well as operating a Mission Planning Lab run at NASA’s Wallops Flight Facility, in Chincoteague, Virginia.
or deny what it is seeing in the light curve. The AI starts out by searching for random patterns, and then small adjustments are made to the patterns to get it closer to the right answer. Then, the researcher gives the AI another example and the process starts over.
“I’m really grateful for the IRAD support, because these very necessary steps simply wouldn’t be possible without it,” Barry said.
“And then you repeat this process many, many times,” Olmschenk said. “And this gets you progressively closer to a generalized answer that works well for any case. This itself is the training algorithm then — it’s a repetitive process where you’re giving the AI an example, asking what its prediction is, updating all the pieces of the AI, and then repeating.”
In order to efficiently find these planets, CUμLUS will use artificial intelligence. Dr. Greg Olmschenk, a postdoctoral researcher working with Barry at Goddard, has developed an AI, called RApid Machine learnEd Triage (RAMjET), for the mission. “I work with certain kinds of artificial intelligence called neural networks,” Olmschenk said. “It’s a type of artificial intelligence that will learn through examples. So, you give it a bunch of examples of the thing you want to find, and the thing you want it to filter out, and then it will learn how to recognize patterns in that data to try to find the things that you want to keep and the things you want to throw away.” Prior to beginning its mission, the AI is trained to know what to look for. This process typically begins by showing the AI, for example, a light curve — a graph that shows the brightness of an object over a particular period of time — and asking it to confirm
Eventually, the AI learns what it needs to identify and will only send back important information. In filtering this information, RAMjET will help save power and memory and keep costs down. “CUμLUS will permit us to estimate many highprecision masses for new planets detected by Roman and PRIME,” Barry said. “And it may allow us to capture or estimate the actual mass of a freefloating planet for the first time — which has never been done before. So cool, and so exciting. Really, it’s a new golden age for astronomy right now, and I’m just very excited about it.” v CONTACT Richard.K.Barry@nasa.gov or 301-286-0664
Small Mission to Shed New Light on Exoplanet Atmospheres A SmallSat mission called Pandora seeks new uses for well-known spectroscopy tools to doublecheck the compositions of exoplanet atmospheres that may have previously been misidentified due to fluctuations in the light of their host stars. “Pandora would be about a meter high and about half a meter wide, and it has two primary ways of measuring,” said Thomas Barclay, a research scientist at the University of Maryland Baltimore County and Goddard. “Light received by the telescope goes behind the mirror and is split into a visible light channel, which will be primarily used for measuring the brightness of the star over time, and an infrared channel, which we primarily use for understanding exoplanet atmospheres.” Most of the 4,400 planets found outside our solar system were discovered because they periodically PAGE 12
block light from their host stars – an event called a transit –as seen from our perspective on Earth. In order to obtain accurate measurements of the star’s brightness before and during the planet’s transit, the analysis methods assume the star’s disk is uniformly bright. However, this is not the case. One way starlight fluctuates is the presence of bright or dark spots rotating into and out of view. These features increase and decrease during the star’s activity cycle. Goddard research scientists Elisa Quintana and Barclay are working on a technology that takes that fluctuation into account. Different chemicals absorb light at different colors, which is true for the gases in exoplanet atmospheres too. Using a spectrometer, astronomers can study which wavelengths are absorbed, which Continued on page 13
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