Canadian Scientist Sara Seager has a gift

Sara Seager at Mauna Loa, Hawaii. Photo credit: Charles Darrow/MIT.

Sara Seager is very smart, just ask the folks at the MacArthur Foundation who gave her one of their prestigious ‘genius’ grants in 2013.

Seager is an astrophysicists and planetary scientist. She was born in Toronto, did her undergrad at the University of Toronto before going to grad school at Harvard. She’s been a professor at the Massachusetts Institute of Technology since 2007.

She’s become known as a leading voice in the planet hunting community. Her work revolves around new techniques in finding planets, known as exoplanets, in other star systems.

The MacArthur Foundation awarded her a fellowship grant for her work in “adapting fundamental maxims of existing planetary science to create a comprehensive theoretical framework for determining the characteristics of planets beyond our solar system.”

That is the basics of her career. But there’s so much more to her story. And for that we turn to a great story, as told in The Daily podcast produced by the New York Times.

Listen to: Sara Seager, the woman who might find us another Earth

The Starshade – A New Worlds Mission

One of the missions Seager has been advocating for, and which is mentioned in the podcast, is the Starshade, a proposed NASA New Worlds Mission.

According to Seager’s website, the “Starshade is a carefully shaped screen with its own spacecraft, which, when flown in formation with a space telescope along the line of sight to a star, blocks enough of the light from the star to reveal any orbiting planets. The starshade size and shape, and the starshade-telescope separation, are chosen to control diffraction around the screen and create a very deep and dark shadow; the planet light is unaffected due to its angular separation from the star. Creating shadows large enough for future space telescopes and deep enough to image Earthlike planets requires starshades that are tens of meters in diameter and separated from the telescope by tens of thousands of kilometers.”

Starshade Artist's Concept 2
Starshade Artist’s Concept 2. Photo credit: NASA/JPL-Caltech.

“Use of a starshade to suppress starlight has several key strengths for discovering and characterizing nearby Earth analogs. First and foremost, because starlight is blocked before entering the telescope, no complicated optics are required, resulting in high throughput and allowing the use of any relatively small commercially available space telescope. This is in contrast to the lower throughput observatory and extremely specialized and difficult wavefront sensing and control system required for the internal coronagraph technique. Second, the inner working angle (iwa) of the starshade/telescope combination (the smallest angle on the sky at which an orbiting companion can be detected) is independent of telescope aperture. Rather, it is determined by the starshade size and separation from the telescope. Similarly, a starshade based observing system has no limiting outer working angle; the field of view is only limited by detector size.”

“A starshade-based starlight suppression system is, of course, not without its own challenges. The starshade must be manufactured to the required shape while meeting precise tolerances, the petal edges must be carefully designed to be small enough to minimize sunlight scatter into the telescope, the starshade must be deployed while meeting tight positioning requirements, the starshade must be precisely positioned and pointed during observation, and the basic optical response must be understood and proven. Nevertheless, while many of these challenges are new, the starshade structure has heritage from large radio antenna deployables and the JWST sunshield; and the fundamental engineering behind the structure and deployment is well understood.”

The Starshade project has completed some preliminary studies but has yet to be given the green light by NASA as a mission.

I suspect it will be a while before the mission gets funded. At the moment the James Webb Space Telescope still needs to launch. That project has been way over budget, and I suspect another large expenditure of the type needed for Starshade will be hard to come by, especially in the tough economic times we’re in.

For now though, Seager will use other telescopes at her disposal. She is also likely to come up with new ideas and techniques to find exoplanets, including possibly Earth like planets.

About Marc Boucher

Boucher is an entrepreneur, writer, editor & publisher. He is the founder of SpaceQ Media Inc. and CEO and co-founder of SpaceRef Interactive LLC. Boucher has 20+ years working in various roles in the space industry and a total of 30 years as a technology entrepreneur including creating Maple Square, Canada's first internet directory and search engine.

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