SLAS Regular Meeting
Friday, April 17, 2015 7:30pm
McDonnell Hall, Washington University

Rosetta at Comet 67P
by
Joseph Marcus, MD

Hailed by Science magazine as the 2014 "Breakthrough of the Year," the European Space Agency's Rosetta spacecraft Rosetta is revolutionizing our understanding of comets. Aided by gravitational slingshot assists from Earth and Mars, the spacecraft reached its quarry and completed a ten-year, billion mile journey to become the first to orbit, rather than to fly by, a comet comet 67P/Churyumov-Gerasimenko, in August, 2014. There it found a bizarre dust-covered world of pits, crevices, cliffs, cracks, boulders, "goosebumps," and even dunes. On November 12, Rosetta's Philae lander was launched. The microgravity of this tiny 4-km bi-lobed comet proved quite a challenge to the lander, which bounced several times from an unexpectedly hard surface, finally coming to rest in a heavily-shadowed cliff region whose location is still unknown, But before it went to "sleep" after battery depletion, it returned
stunning images and other data from the surface, and it may yet awaken. The Rosetta orbiter has continued to function, sending images and data 300 million miles back to Earth. A visit with the co-discoverer, Klim Churyumov, in Kyiv is recounted. Dr. Marcus will describe the nature and origin of comets as well as examine the early results of the Rosetta mission. He will explain how the comet will change as it approaches its nearest distance to the sun next August, and what scientists hope to learn from the 17-month long Rosetta observations.

Dr. Marcus is an avid astronomer with particular interest in the study of comets. In addition to observing them, he was editor of The Comet News Service, a quarterly and specialedition publication of the McDonnell Planetarium in the mid-seventies and early eighties.

Meeting Agenda

Welcome

Introduction of Officers and Visitors

Tyson Raffle

Announcements and Star Parties