Peter B. James, Ph.D.
Associate Professor Baylor University
Media
Biography
Dr. James's current activities in the Geosciences Department include teaching, advisement, and research. If you are interested in pursuing a research project with Dr. James, shoot him an email.
Areas of Expertise
Accomplishments
Group Achievement Award (MESSENGER)
NASA
2018
Early Career Award
NASA
2024
Education
Massachusetts Institute of Technology
Ph.D.
Planetary Science
2013
Brown University
Sc.B.
Geology/Physics–Mathematics
2007
Brown University
A.B.
Physics
2007
Media Appearances
Scientists discover gigantic 'structure' under the surface of the Moon
Indy100 online
2025-06-18
The basin itself is enormous, stretching roughly the distance from Waco, Texas, to Washington, D.C., and plunging several miles deep. Despite its size, you cannot see it from Earth because it lies on the far side. The discovery was announced in the journal Geophysical Research Letters by Peter B. James, a planetary geophysics professor at Baylor University.
Scientists discover previously unidentified mass beneath moon's surface
CBS News online
2019-06-11
"Imagine taking a pile of metal five times larger than the Big Island of Hawaii and burying it underground. That's roughly how much unexpected mass we detected," said lead author Peter B. James, Ph.D., assistant professor of planetary geophysics in Baylor's College of Arts & Sciences.
There’s An Enormous, Mysterious Mass Under the Moon’s Largest Crater
Discover Magazine online
2019-06-11
Astronomers led by Peter B. James from Baylor University discovered the hidden feature by combining data from NASA’s GRAIL lunar orbiter mission and the Lunar Reconnaissance Orbiter to look at where regions of high gravity — and therefore mass — overlap with surface features like craters. They found a giant mass weighing down the floor of the South Pole-Aitken basin by more than a half mile.
Articles
Modeling Development of a Diamagnetically Stabilized Magnetically Levitated Gravimeter
Sensors2024
The aim of this work is to create a new type of gravimeter that can function effectively in the challenging conditions of space, specifically on the surfaces of planets and moons. The proposed device, called a diamagnetically stabilized magnetically levitated gravimeter (DSMLG), uses magnetic forces to balance a test mass against the force of gravity, allowing for accurate measurements.
Don’t judge the Moon’s interior by its cover
Nature Geoscience2024
The Moon’s primordial solidification is believed to have produced a layer of dense ilmenite cumulates beneath the crust. Remnants of this layer have now been detected under the lunar nearside.
Evaluating the use of seasonal surface displacements and time‐variable gravity to constrain the interior of Mars
Journal of Geophysical Research: Planets2024
The mass transport of volatiles on Mars represents a seasonally changing load on the surface of the planet. Like on Earth, as mass is redistributed across the planet, the surface responds in a complex manner becoming displaced downwards or upwards. The magnitude and extent of displacement depend on the properties of the load and mechanical properties of the planetary interior. Based on new estimates of the height variation of the seasonal polar caps (SPCs), we predict local surface displacements of up to tens of millimeters with a strong degree 1 signal throughout the Martian year. The long‐wavelength portion of the displacement is potentially observable, with a magnitude of a few millimeters, located away from the SPC where one could realistically measure it with a landed or orbital mission.
The effect of antecedent topography on complex crater formation
Geophysical Research Letters2024
Impact craters that form on every planetary body provide a record of planetary surface evolution. On heavily cratered surfaces, new craters that form often overlap antecedent craters, but it is unknown how the presence of antecedent craters alters impact crater formation. We use overlapping complex crater pairs on the lunar surface to constrain this process and find that crater rims are systematically lower where they intersect antecedent crater basins. The rim morphology of the new crater depends on the depth of the antecedent crater and the degree of overlap between the craters. Our observations suggest that new craters do not always obliterate underlying topography and that transient rim collapse is altered by antecedent topography.
New geophysical constraints for intrusive magmatism at large Martian volcanoes: Implications for crustal thickness and volatile outgassing
Journal of Geophysical Research: Planets2025
Volcanic materials exert both downward and upward forces on a planet's lithosphere, depending on where they are emplaced. On Mars, numerous studies have used gravity and topography data to ascertain the contribution of each of these styles of emplacement to measured fields. We use a novel methodology that allows for the thickness of an intrusive body to vary to more thoroughly model how intrusive magma flexes the lithosphere and use this to estimate the relative proportion of intrusive to extrusive materials under major Martian volcanoes. We find proportions that imply larger volumes of intrusive material compared to erupted, which is more in line with non‐geophysical methods. Our results additionally imply a significant volume of outgassed volatiles into the atmosphere relatively later in Martian history which has implications for the thickness and composition of the ancient Martian atmosphere.
