Periodically, gravitational forces cause comets, such as Lovejoy seen here, to shoot from the outer solar system toward the sun where they pose a danger to Earth-bound life. (Credit:听NASA/MSFC/MEO/Aaron Kingery)
Ann-Marie Madigan
A 抖阴旅行射 Boulder researcher who investigates the unusual behavior of icy objects at the outermost edges of the solar system has been named a 2018 Packard Fellow.听
Ann-Marie Madigan is one of 18 scientists and engineers receiving this honor, which is . The award comes with a no-strings-attached, five-year grant of $875,000 to support 鈥渢he blue-sky thinking鈥� of researchers across the country.
Madigan, an assistant professor in the Department of Astrophysics and Planetary Sciences (APS) and an associate fellow of , said that she will use the award to explore the motion of 鈥渢rans-Neptunian objects鈥�鈥攊cy bodies that orbit the sun billions of miles from Earth.听
In particular, she plans to dig into an improbable-sounding space mystery: Did jostling and crashing among these comets help lead to the extinction of the dinosaurs?
鈥淭hese bodies can be small, but there are so many of them that, collectively, they can change each other鈥檚 orbits and send comets shooting into the inner solar system and where they can potentially smash into Earth,鈥� Madigan said. 鈥淚t鈥檚 about time that we begin to understand what that collective gravity does.鈥�
鈥淧rofessor Madigan is a creative and nimble theoretical astrophysicist,鈥� said Nils Halverson, chair of APS. 鈥淲ith her Packard Fellowship, she will apply her theoretical tools to understanding orbital dynamics in our own solar system, possibly yielding insight into what caused the mass extinction of the dinosaurs. I鈥檓 proud to have her as a faculty member in our department and excited to support her work.鈥�
Now in their 30th year, the Packard Fellowships for Science and Engineering seek to promote research that 鈥渙ver time will lead to new discoveries that improve people鈥檚 lives and enhance our understanding of the universe.鈥�
Madigan is the 16th Packard Fellow to hail from 抖阴旅行射 Boulder. Christoph Keplinger, an assistant professor in the Department of Mechanical Engineering, was named a fellow in 2017 for his innovations in building soft machines.
听鈥淛ILA is delighted that Ann-Marie鈥檚 past accomplishments and future success are being recognized with a Packard Fellowship to study the collective gravity of comets,鈥� said Tom Perkins, chair of JILA, a joint institute of 抖阴旅行射 Boulder and the National Institute for Standards and Technology (NIST).
Collective gravity
Madigan received a Master鈥檚 and Ph.D. degree in astronomy from Leiden University in the Netherlands. She was a postdoctoral fellow at the University of California, Berkeley before joining the 抖阴旅行射 Boulder faculty in 2016.
Madigan鈥檚 research focuses on astronomical objects with 鈥渆ccentric鈥� orbits, or that move around in space like a stretched-out rubber band. More recently, the scientist鈥攚ho became interested in astrophysics after reading about Einstein鈥檚 theory of relativity in a biography on her parents鈥� bookshelf鈥攈as set her sights on the solar system beyond Neptune鈥檚 orbit.听
She said that, despite being relatively close to Earth, this stretch of space isn鈥檛 well understood by scientists. 鈥淲e have more comets and asteroids in our solar system than we have stars in our galaxy,鈥� Madigan said. 鈥淏ut they鈥檙e so dark and so hard to see that we don鈥檛 understand what large-scale structures they form.鈥�
With funding from the Packard Foundation, Madigan is hoping to better understand those dark objects. In a series of recent studies, she has argued that, like a game of space billiards, these trillions of icy bodies exert a gravitational pull on each other鈥攑otentially nudging comets or minor planets into strange orbits.听
Such 鈥渃ollective gravity鈥� may also create regular cycles in which comets move closer to or farther away from Earth. That, in turn, may cause space debris to pummel the planet at predictable intervals, including around 65 million years ago when the Triceratops met its end.听
鈥淲e鈥檙e trying to connect that impact event with what is going on in the broader solar system,鈥� Madigan said. 鈥淚n that way, the collective gravity of trillions of comets could play a role.鈥�
Or, as Madigan put it, you鈥檒l never know if you don鈥檛 look.
