California Space Grant Consortium Home Page
4 About California Space Grant Consortium Learn about CaSGC Opporunities CaSGC Programs CaSGC Affiliates CaSGC Links CaSGC Contacts CaSGC Site Map

Physical Sciences

Presented by:

    • The James R. Arnold Lectureship Endowment fund
    • The UCSD Division of Physical Sciences
    • The California Space Grant Consortium
    • The UCSD Department of Chemistry & Biochemistry

An endowed lectureship has been established to honor Professor James R. Arnold, one of UCSD's first faculty members and the founding chair of the Chemistry Department. If you would like to contribute to future lectures please click on the the donation form below.

     Donation form for James R. Arnold Lectureship

This is a free public lecture. A reception in honor of Professor Jim Arnold will be held immediately afterwards.

Friday      May 7, 2010        4:00 PM - 6:30 PM

Magnetic Planets and How Mars Lost Its Atmosphere

Friday, May 7, 2010
4:00 PM - 6:30 P

Auditorium, Natural Sciences Building, Revelle College, UCSD

Directions to Natural Science Building

Link to Presentation Slides

Link to Presentation Video (QuickTime)


Most planets in the solar system, such as the Earth and Jupiter, have strong global magnetic fields that deflect the solar wind around the planet. Mars and the Moon are two planetary bodies without present-day global magnetic fields, but measurements from the Lunar Prospector and Mars Global Surveyor spacecraft, using a novel remote-sensing method of detecting planetary magnetic field discovered serendipitously by the Apollo15 & 16 Subsatellites, have provided maps that show intricate patterns in near-surface magnetic fields of these two bodies. The near-surface fields on Mars appear to be due to the magnetizing of the planetary crust by a strong ancient global magnetic field that disappeared about 4.1 billion years ago. Observations from other Mars missions (such as the Mars Rovers) indicate that liquid water was present on the Mars surface in ancient times, implying a much thicker atmosphere than at present. An interesting hypothesis for the disappearance of this thick atmosphere is that once the strong global magnetic field disappeared, the solar wind was able to penetrate into the Martian atmosphere and scour it away. I will describe the MAVEN (Mars Atmosphere and Volatiles EvolutioN) Mars Scout mission (presently being developed for a 2013 launch) that is designed to find out what physical processes led to the loss of atmosphere from Mars, and how effective these processes might have been when the Sun was young and much more active than at present. 


Photo of Bob Lin

Bob Lin

Professor of Physics,
University of California, Berkeley

Bob Lin is a Professor of Physics at the University of California, Berkeley, and a world-renowned experimental space physicist, with broad research interests ranging from solar and heliospheric physics, to lunar and planetary science.  His primary interest is in how particles are accelerated to high energies in nature.  He has developed and flown numerous, innovative instruments on NASA missions to directly measure the plasma, fields, and energetic particles in regions where particle acceleration is occurring; and to do imaging and spectroscopy of the x-rays and gamma-rays emitted by energetic particles at the Sun. As part of the Apollo program, he and his colleagues developed the Apollo15 & 16 Subsatellites that were left in lunar orbit to probe the behavior of the Earth’s distant magnetotail, and serendipitously discovered a new method to detect planetary magnetic fields remotely, using the magnetic reflection of electrons. He applied this method on the Lunar Prospector and the Mars Global Surveyor missions to map the crustal magnetic fields of the Moon and Mars, respectively, with extremely high sensitivity. 

Bob received his B.S. (1962) from Caltech and Ph.D. (1967) in Physics from the University of California, Berkeley (UCB).  He served as Director of the UCB Space Sciences Laboratory at Berkeley from 1998 to 2008. He has received numerous awards and honors, including the George Ellery Hale Prize of the American Astronomical Society, and an honorary Docteur Honoris Causa de l’Universite de Toulouse, as well as many NASA achievement awards. He is a member of the National Academy of Sciences and of the American Academy of Arts and Sciences, and a Fellow of the American Geophysical Union.  Bob currently serves on the Editorial Boards of the Space Science Reviews, Solar Physics, and Annual Reviews of Astronomy & Astrophysics; and he is the Principal Investigator for the RHESSI (Ramaty High Energy Solar Spectroscopic Imager) Small Explorer mission and for the Wind 3D Plasma & Energetic Particles instrument, and Deputy PI for the MAVEN (Mars Atmosphere & Volatiles EvolutioN) Mars Scout mission planned for launch in 2013.


  National Aeronautics
and Space Administration
Link to NASA's Website Link to National Space Grant Website National Space Grant College
and Fellowship Program
Copyright 2007 California Space Grant Consortium
Questions or Comments E-mail: Webmaster
last modified on
Link to CaSGC Home Page Link to CaSGC Home Page Affiliates click here to log into the CaSGC Affiliate Area Link to CaSGC Home