Horton Elwood Newsom was killed in a car accident in Albuquerque, NM, April 19, 2024. Hort was widely known and respected in our community for his work in experimental and analytical geochemistry; impact cratering; and his active participation in spacecraft missions at Mars. Hort’s cheerful presence will be deeply missed.
Horton was born on March 2, 1952 in Alameda, California. He received his B.A. in Geology from nearby University of California Berkeley in 1974, and his M.S. and Ph.D. in Geosciences in 1982 from the University of Arizona. His advisor was Mike Drake, a celebrated cosmochemist and lead Principal Investigator for the OSIRIS-Rex asteroid-sample-return mission. Hort’s Ph.D. dissertation focused on experimental geochemistry of two siderophile elements (W, P) and their implications for understanding core formation in differentiated planetary bodies. Prior to this, Hort had also done a Master’s thesis, studying the Bencubbin meteorite. In parallel with his experimental and petrologic studies, Hort began a third research direction – impact cratering, with emphasis on alteration of impact melts.
After graduation from Arizona, Hort took a position as a post-doc at the Max-Planck-Institut für Kosmochemie in Mainz, Germany. There, he worked with Herbert Palme and Günther Graup, expanding on his earlier experimental work, and studying hydrothermal alteration of Ries crater ejecta.
In 1986, Hort took a position as a Research Scientist at the Institute for Meteoritics at the University of New Mexico (Albuquerque), where he settled and stayed throughout his career. Hort continued his contributions to impact processes and planetary chemistry. Highlights of this time include studies on the Lonar impact crater (India), and participation in the Origin of the Moon conference and book (1986), which revived the theory of the Moon’s formation by a giant impact onto the Earth. Hort followed this by conceiving the Origin of the Earth conference (1988), for which he was lead editor of the conference’s 1990 publication.
Hort’s knowledge of chemical analysis by gamma-ray spectrometry (learned in Mainz) led to his selection to the science team for the Mars Global Surveyor orbiter mission (1999-2006), where he helped map and interpret the chemistry of Mars’ surface. That experience led to his inclusion on the science teams for the Mars Exploration Rover Missions (2004-2019) and the Mars Science Laboratory’s Curiosity rover (2014 - present).
For Curiosity, Hort was a member of the ChemCam team, where he worked with its chemical analyses of rocks and soils in Gale Crater. He was an active contributor to tactical and strategic operations planning, freely contributing his broad expertise in geochemistry and impact processes to the mission. He was active in reporting Curiosity’s results and discoveries and was author and co-author of numerous papers on topics including: impact processes, diagenesis, stratigraphy, and the chemistry of manganese.
Outside his science achievements, Hort led an active life with his family and community. He loved Taekwondo, and achieved 6th Degree Black Belt. He was awarded Master status in 2021, and was head instructor at the ATA of Albuquerque. Hort was active in science education, both by acting as Curator of the university’s Institute-of-Meteoritics Meteorite Museum and by pioneering programs at UNM to include Native Americans in geology and meteorite science.
Hort is survived by his wife, Joan, and two children Emily and Gary. His cheerful view on life, and his willingness to collaborate, will be missed by all his colleagues and friends.
There will be a memorial service for Horton Newsom at UNM in Albuquerque on March 1, 2025. For more information, please contact Joan.Newsom@gmail.com
Submitted by: John Jones, Allan Treiman