November 1, 2012
Filed Under North Tahoe Events
Bill Cooke, head of NASA’s Meteoroid Environment Office, estimated the mass of the incoming object of around 70 metric tons. Holy Batman!
The minivan-sized meteorite that broke up over the Sierra on Sunday, April 22, 2012 was not just any old space rock. It was one of the rarest types of meteorites to fall to Earth — a carbonaceous chondrite, the earliest solid material to form in our Solar System more than four and a half billion years ago, before the planets, including the Earth, formed.
Learn more during the Meteorite Fragments Provide View into the Earliest History of the Solar System on November 1, 2012 with Dr. Lin, UC Davis Geology Department. $5 donation only.
This meteorite could turn out to be one of the most important observed fall since the late 1960s, says UC Davis geology professor Qing-Zhu Yin. These primitive meteorites provide a glimpse into the first few millions of years of the Solar System’s history. This meteorite fall came at the opportune time as both NASA and JAXA (NASA’s counter part in Japan) prepare two space craft sample return missions (OSIRIS REx and Hayabusa-2) from the two carbonaceous chondrite parent asteroids, which may hold clues to the origin of the Solar System and organic molecules as building blocks for life.
Ian O’Neill of Discovery News said it slammed into Earth’s atmosphere, “at a speed of 15 kilometers per second (33,500 mph), turning into a fireball, and delivering an energy of 3.8 kilotons of TNT as it broke up over California’s Sierra Nevada mountains.”
Many in Nevada and California on the morning of April 22, 2012 saw a bright flash across the sky, and heard an audible boom, or explosion. Astronomers say it was a meteor, or piece of space debris entering Earth’s atmosphere. The object is now being called “a small asteroid” whose estimated weight was some 70 metric tons. It apparently broke up in the atmosphere. There is still speculation that some pieces might have fallen to Earth, in which case scientists might mount a search to locate the pieces.
Professor Qing-Zhu Yin of the UC Davis Department of Geology uses extinct radioactivity and general isotopic anomalies in the early solar system recorded in primitive meteorites as a tool to study the time scales and site of nucleosynthesis, the time of formation of the solar system and planetary differentiation. Professor Qing-Zhu Yin’s research focuses primarily on reconstructing the history of chemical and physical processes involved in the formation of the Sun and the planets. To address these problems, he studies the isotopic compositions of those elements, which were produced during nucleosynthetic processes in stellar outflows, sprinkled into interstellar medium, and subsequently mixed into the solar nebula ~4567 million years (Ma) ago, and locked into a diverse set of planetary materials including the Earth. Some of these newly generated nuclides decay radioactively with relatively short half-lives (t1/2 =0.1-10 Ma). These short-lived radionuclides can therefore be used to obtain high-resolution chronologic constraints on early solar system processes.
In this general public talk, Dr. Yin will review what scientists could learn and have already learned about the origin of our solar system from the Sutter’s Mill meteorite and similar meteorite fall like the one in Sutter’s Mill; why scientists need a lot more materials; how to identify the general features of CM carbonaceous chondrites in the field, with examples from Sutter’s Mill; how to handle the sample for safe storage, how we might be able to find more samples before the rainy season starts, followed by a brief question-and-answer session.
For more information, contact Heather Segale at 775-881-7562.
Meteorite Fragments Provide View into the Earliest History of the Solar System
November 1, 2012
No-host bar at 5:30. Presentation begins at 6 p.m.
$5 Donation suggested.