Jan

17

2021

Dr. Sara Russell, NHM London

Clocks in Rocks - How to date a solar system

Location: https://ucla.zoom.us/meeting/register/tJEqduyupj0vGd3S0_52FsbHTbPjYr0sZQUj
Time: 2:30PM

Our solar system was born over four and a half billion years ago, from a cloud of dust and gas called the protoplanetary disk. Examples of the first solids to be formed - calcium-aluminium-rich inclusions (CAIs) and chondrules -have survived in some meteorite samples to learn about these ancient times. In particular, we can determine how old these components are using lead isotopes, which places constraints on the formation time of our Sun and planets. Finer details can be provided by the isotope 26Al, which is a natural clock because it is radioactive and its abundance declines by half every 3/4 of a million years. By looking at how much of this isotope was present in each object when it formed we can therefore tell how old it is. However, this chronometer depends on knowing how much 26Al originally existed in the disk and how it was distributed. If we can work these details out, then we can use these data to determine the length of time it took to make CAIs and chondrules, and from this we can work out how long the dusty disk took to start to form planets.

Nov

15

2020

Dr. Adrian Brearley

Child’s Play- Fun and Games with Mud and Goo in the Early Solar System

Location: Registration: https://ucla.zoom.us/meeting/register/tJEqduyupj0vGd3S0_52FsbHTbPjYr0sZQUj
Time: 2:30PM

The carbonaceous chondrite meteorites contain a diverse array of early solar system materials. Among the most challenging of these materials to study is the very fine-grained, so called 'matrix' of these meteorites. In this presentation, I will discuss the evolution of our understanding of these fine-grained materials and what they tell us about early solar system processes. In particular, I will focus on the fine-grained silicate mineral component of pristine carbonaceous chondrite matrices - the 'mud' and its intimate relationship with organic carbonaceous matter, the 'goo', to illustrate new insights into the behavior of water and organic matter in the early solar system. The significant advances that have been made in studying these materials is also a remarkable demonstration of the development and application of state-of-the-art micro and nanoanalytical techniques to study extraterrestrial samples. These include the precious samples of carbonaceous asteroids that are on their way back to Earth carried by the JAXA Hayabusa 2 and NASA OSIRIS-Rex sample return missions.

Nov

1

2020

UCLA Meteorite Scientists

Exploring Your Universe 2020

Location: https://hopin.to/events/eyu
Time: 12PM

This is a FREE event for visitors of all ages and scientific backgrounds. Exploring Your Universe was founded in 2009 by graduate students in UCLA’s Astronomy department, and is now organized by volunteer graduate students representing several UCLA departments. As the largest science outreach event on campus, this event is made possible by volunteers from student groups, departments, and faculty across all science disciplines. This year there will be no physical event held on UCLA’s campus. We will be going VIRTUAL! We have built a virtual platform specially for this event in order to curate an immersive experience that includes a combination of interactive booths, demonstrations, live speakers, and Q&A panels. Copy and paste the link in your browser to reach the registration page so that you can join us anywhere in the world on Nov. 1st! The UCLA Meteorite Collection is hosting a booth with EYU which includes includes live lectures from 12-5 p.m. including a Q&A with Meteorite Scientists from 4-5 p.m. on November 1st.

Oct

18

2020

Dr. Donald Brownlee

The Golden Age of Sample Return Missions from Space: What comet samples have told us about the origin of the solar system

Location: https://ucla.zoom.us/meeting/register/tJEqduyupj0vGd3S0_52FsbHTbPjYr0sZQUj
Time: 2:30PM

In the past 15 years, space missions have returned samples of the Sun, a comet and an asteroid for detailed study by state-of-the-art methods in laboratories around the world. Samples from two additional asteroids are being returned by current missions and return missions from the Moon and Mars are planned. Starting 30 years after the last Apollo lunar mission, some have called these new missions the Golden Age of post-Apollo sample return missions. In this talk, I will describe the Stardust mission and how the ancient rocky materials it returned from an active comet have given us important new insight into the formation of icy-bodies near the edge of the solar system. Just as Moore’s Law led to vast improvements in our computers, analogous advances in microanalytical methods have led to unprecedented capabilities for studying extraterrestrial materials. In the case of comet samples, the analyses have found abundant rocky materials that formed at incandescent temperatures, probably in the inner solar system. Such materials were profoundly unexpected components in a body whose ices formed at cryogenic temperature. Their presence in comets is evidence of large scale transport of rocky materials from the hottest regions of the early solar system to its coldest parts.

Sep

20

2020

Dr. Andrew Davis

Rocks and Minerals from Stars

Location: https://ucla.zoom.us/meeting/register/tJEqduyupj0vGd3S0_52FsbHTbPjYr0sZQUj
Time: 2:30PM

One of the most remarkable discoveries of the twentieth century is that some meteorites contain dust grains made around other stars that lived and died more than 4.5 billion years ago, before our Solar System formed. Stars only twice the mass of our Sun eventually turned into red giant stars and lost much of their mass as gas and dust. More massive stars ended with spectacular explosions called supernovae, and throw off much of their mass. Both kinds of stars return copious amounts of dust to the interstellar medium (the stuff between the stars), a portion of which formed new stars like our own, and we have recognized dust grains from both red giants and supernovae in meteorites. Each dust grain retains a chemical and isotopic record of the star around which it formed and by analyzing individual dust grains in the laboratory, we can study the interiors of stars in ways not possible by astronomy with telescopes. The study of stardust in the laboratory has led to new understanding of how the chemical elements are made in stars. Stardust was also not uniformly mixed into the solar nebula, the disk of gas and dust from which the Sun and planets formed. This caused small differences in isotopic composition among Solar System materials that have proven to be powerful tracers of the relationships between planets and different kinds of meteorites.