Dates, Speakers Announced for Spring 2020 Neighborhood Lecture Series
UPDATE: We regret to announce that the Spring Neighborhood Lecture Series has been postponed due to growing concerns over the spread of COVID-19.
Carnegie Science's Earth and Planets Laboratory will host this Spring's Neighborhood Lecture series at the Carnegie Institution for Science's beautiful Broad Branch Road (BBR) campus in Northwest Washington, DC. Our Neighborhood Lectures provide an opportunity to explore the world from the perspective of scientists who are working at the leading edge of scientific discovery. These lectures begin at 6:30 p.m. and last for approximately one hour, followed by a brief question and answer period.
Thursday | March 26, 2020 | 6:30 p.m.
The origin of the Earth and Moon is one of science’s greatest mystery stories, complete with false starts and dead ends. The Apollo missions shattered all the previous ideas about making the Moon. But the precious lunar samples contain a major clue to our planet’s creation: the Moon is Earth’s isotopic twin. The isotopes of different elements are like a planetary fingerprint: no two bodies are the same – except the Earth and Moon. After Apollo, a giant impact became the most likely explanation for the Moon, but it failed to explain this key observation. Stewart will talk about the accidental discovery of a new type of astronomical object, called a synestia, that may save the idea of a giant impact and forever change the way you think about the birth of our planet.
Presented by Dr. Sarah T. Stewart from the University of California, Davis
Thursday | April 16, 2020 | 6:30 p.m.
Earth is unique amongst the rocky planets in having two very different types of crust. Continental crust is composed primarily of silica-rich rocks like the granite of your kitchen countertops. Oceanic crust is instead almost entirely a black magnesium and iron-rich volcanic rock, basalt, like that erupted in Hawaii. The continental crust is above water because it is thick, and granite is less dense than basalt, so it floats higher on top of Earth’s interior. Oceanic crust sinks back into Earth’s interior on hundred million year timescales. In contrast, the buoyancy of continental crust allows it to survive longer at Earth’s surface. Even so, only a very small portion of Earth’s surface consists of rocks formed within half a billion years of Earth formation. Carlson will discuss the continuing efforts to find these rare remnants of Earth’s oldest crust and what they can tell us about what our home planet was like in its infancy.
Presented by Dr. Richard Carlson, Director of Carnegie Earth and Planets Laboratory