Jim Bell

Chapter 1 · 1976 – 1992 Mars pictures on the evening news

In 1976, an eleven-year-old boy watched on the nightly TV news the first images sent back by the Viking landers from the surface of Mars. That was, NASA says, Jim Bell’s first experience with Mars pictures. He would spend his life making them.

Caltech, then Hawaii

He studied at the California Institute of Technology, Caltech, where he earned a bachelor’s degree in planetary science and aeronautics. He went on to the University of Hawaii, where he received a master’s degree and a Ph.D. in geology and geophysics.

Watching Mars from Mauna Kea

In Hawaii, with Thomas McCord, he observed Mars from the summit of Mauna Kea. During the 1986 opposition, when Mars came closest to Earth, they took infrared spectra of several Martian regions with the university’s 88-inch telescope and compared them with one another. He did it again at the 1988 and 1990 oppositions, with digital cameras able to take images at many wavelengths: imaging spectroscopy, which maps the composition of a surface color by color.

His results, published in 1992 and 1993, showed that extremely fine-grained, so-called “nanophase” iron oxides dominate the color of the Martian surface in the visible and near-infrared. With Richard Morris and John Adams, he studied a terrestrial analog: altered volcanic ash on Mauna Kea, heated by a lava flow, whose mineralogy resembles that of Martian soil and dust. Precise imaging, he concluded, is an ideal tool for studying the Martian surface, from Earth as well as from spacecraft.

Sources: NASA/JPL, “NASA’s Perseverance Rover Will Look at Mars Through These ‘Eyes,’” May 1, 2020 (at 11, the Viking images on the TV news in 1976); Arizona State University, Jim Bell’s “About” page (Caltech B.S., Hawaii M.S. and Ph.D.); J. F. Bell III and T. B. McCord (University of Hawaii), 1987 (NTRS 19880020274: 1986 opposition, Mauna Kea 88-inch telescope, compared spectra); NTRS 19900046443 (1988 opposition) and 19920068812 (1990, with D. Crisp); J. F. Bell III, “Charge-coupled device imaging spectroscopy of Mars. II,” Icarus, 1992 (NTRS 19930038746: nanophase ferric oxides, ideal tool); J. F. Bell III, R. V. Morris and J. B. Adams, Journal of Geophysical Research, 1993 (NTRS 19930046763: Mauna Kea palagonitic tephra). The explanations of opposition and imaging spectroscopy are general notions.

Chapter 2 · 1992 – 2003 From Ames to Cornell, the eye of Pancam

After his doctorate, Jim Bell moved from telescopes to spacecraft. With Steve Squyres’s team, he would build the eyes of the Spirit and Opportunity rovers.

NASA Ames and Hubble

He was first a National Research Council postdoctoral fellow at NASA’s Ames Research Center in California, where he worked among others with James Pollack on the narrow absorption lines in the spectrum of Mars. He then joined Cornell University. In 2000, from Cornell, he presented with Michael Wolff new spectroscopic images of Mars taken with the Hubble Space Telescope, to map the iron minerals of the surface.

One mission after another

He took part in the NEAR mission to the asteroid Eros, about which he co-edited a book, Asteroid Rendezvous, in Mars Pathfinder, in the CONTOUR comet mission, and later in Mars Odyssey and Mars Reconnaissance Orbiter.

Pancam

For the 2003 rovers, he led the Panoramic Camera, Pancam, of the Athena science payload. On each rover, two digital cameras sit on a mast that raises them to 1.5 meters and turns them through 360 degrees, from zenith to nadir: a multispectral, stereoscopic, panoramic system that sees the whole scene around the rover. The name Pancam came from a camera Steve Squyres had proposed, unsuccessfully, for Mars Pathfinder; only the name had survived.

Sources: Arizona State University, Jim Bell’s “About” page (NRC postdoc at Ames, NEAR, Pathfinder, CONTOUR, Odyssey, MRO, Hubble, Asteroid Rendezvous, Pancam lead scientist); J. F. Bell III, J. B. Pollack and T. R. Geballe (Ames), 1994 (NTRS 19950054942); J. F. Bell III (Cornell) and M. J. Wolff, “Visible to Near-IR Imaging Spectroscopy of Mars Using HST,” 2000 (NTRS 20000080763); J. F. Bell III et al., “The Athena Pancam and Color Microscopic Imager,” 2000 (NTRS 20010023047); J. F. Bell III, S. W. Squyres et al., “The Panoramic Camera (Pancam) Investigation on the NASA 2003 Mars Exploration Rover Mission,” 2003 (NTRS 20030110977: two cameras, 1.5 m mast, 360°, multispectral and stereoscopic); NASA, Steve Squyres oral history interview, August 22, 2017 (origin of the Pancam name). Steve Squyres has his own biography in this collection.

Chapter 3 · 2004 – 2019 Postcards from Mars

In January 2004, Spirit and then Opportunity landed on Mars. For fifteen years, Pancam’s images became the world’s postcards from Mars.

Gusev and Meridiani

At Gusev, Pancam revealed a rock-strewn surface, with fine-grained deposits in drifts or small hollows, and iron-rich dust coating almost everything. Where the rover brushed or ground the rock, spectra showed minerals such as pyroxene or olivine. At Meridiani, the images showed a dark, flat, nearly rock-free plain, but, in craters and fractures, brighter layered rocks out of which tiny spheres a few millimeters across were eroding. Spectra of the spheres and the layered rocks indicated crystalline iron oxides.

The sky, the moons and the Earth

Pancam did not look only at the ground. Both teams tracked the decline of dust in the atmosphere, photographed the moons Phobos and Deimos crossing the Sun, Martian sunsets and, from Gusev, the Earth seen from the surface of Mars. In 2005 Bell published large multispectral panoramas taken by both rovers.

Sundials on Mars

To set their colors, the cameras aim at a calibration target that doubles as a sundial. On Spirit and Opportunity, it bore the motto “Two Worlds, One Sun.” Bell enjoys these embellishments, which NASA calls “festooning”: they add, he says, artistic elements to missions dominated by science and technology, and pay tribute to colleagues who paved the way. He has helped festoon almost all of NASA’s Mars rovers.

In 2006 he published Postcards from Mars, a book of rover images for the general public, followed by Mars 3-D in 2008. A former summer student would recall analyzing data from Opportunity’s camera with him.

Sources: J. F. Bell III et al., “Pancam multispectral imaging results from the Spirit Rover at Gusev Crater,” Science, 2004 (NTRS 20050151402) and “… from the Opportunity Rover at Meridiani Planum,” Science, 2004 (NTRS 20050148620); J. F. Bell III et al., 2005 (NTRS 20050166937: large panoramas); NASA/JPL, “5 Hidden Gems Are Riding Aboard NASA’s Perseverance Rover,” December 8, 2020 (sundials, “Two Worlds, One Sun,” “festooning,” quotation, almost all rovers); Arizona State University, Jim Bell’s “About” page (Postcards from Mars, 2006, Mars 3-D, 2008); NASA, “Small Steps, Giant Leaps” podcast, episode 9, 2019 (the former summer student).

Chapter 4 · 2007 – 2025 Mastcam, then Mastcam-Z

After Spirit and Opportunity, Jim Bell worked on the cameras of the next two rovers. With Perseverance, he finally achieved an idea that had failed on Curiosity: a Martian camera that zooms.

Curiosity and the missing zoom

Now a professor at Arizona State University’s School of Earth and Space Exploration, in Tempe, he was, on Curiosity, deputy principal investigator of Mastcam, the mast camera. “The original plan was for Curiosity to have a zoom camera that could go out to an extreme wide angle like a spaghetti western view,” he recalls. “It would have been an amazing panoramic perspective but proved really hard to build at the time.” So Curiosity carries a fixed telephoto lens and a fixed wide-angle lens.

The first color zoom on Mars

On July 31, 2014, NASA presented the principal investigators of the Mars 2020 instruments; Bell was one of them. His camera, Mastcam-Z, for “zoom,” would be “the first Mars color camera that can zoom, enabling 3D images at unprecedented resolution,” he said in 2019: 0.8 millimeters in front of the rover, under 38 millimeters at 100 meters. The two cameras, mounted on the mast at the eye level of a person two meters tall and set 24 centimeters apart, help drivers choose their route and geologists choose rocks and samples, and observe the Sun, the sky and the transits of the moons. Mastcam-Z is not a spectrometer, he points out, “but it can provide mineral clues that other instruments will follow up on.”

On Perseverance’s calibration target, the sundial bears a new motto: “Two Worlds, One Beginning,” a nod to the shared dust from which Earth and Mars were born.

“The images belong to all of us”

Perseverance landed in Jezero crater on February 18, 2021. On the 21st, Mastcam-Z took its first panorama, stitched from 142 images, showing the crater rim and the cliff face of an ancient delta. “We’re nestled right in a sweet spot,” Bell said. The team planned to share images and mosaics made by amateurs on a public website: “It’s important that the public have a sense of ownership. The Mastcam-Z images belong to all of us.”

By 2025, Perseverance had reached the top of Jezero’s rim. On May 26, Mastcam-Z captured an exceptionally sharp mosaic. “The relatively dust-free skies provide a clear view of the surrounding terrain,” he explained.

Sources: Arizona State University, Jim Bell’s “About” page (professor at the School of Earth and Space Exploration, Mastcam deputy principal investigator); NASA/JPL, “NASA’s Perseverance Rover Will Look at Mars Through These ‘Eyes,’” May 1, 2020 (quotations, Curiosity’s lenses, Mastcam-Z’s roles); NASA, “NASA Hosts 3 p.m. EDT Teleconference with Mars 2020 Principal Investigators,” July 31, 2014; NASA, “NASA’s Mars 2020 Gets HD Eyes,” May 31, 2019 (quotation, resolutions); NASA, “NASA’s Perseverance Rover Gives High-Definition Panoramic View of Landing Site,” February 24, 2021 (landing on February 18, panorama on the 21st, 142 images, delta, quotation, 2 m, 24.1 cm); NASA/JPL, “5 Hidden Gems…,” December 8, 2020 (“Two Worlds, One Beginning”); NASA, “NASA’s Perseverance Rover Captures Mars Vista As Clear As Day,” August 6, 2025 (quotation, May 26, 2025, top of the rim).

Chapter 5 · 2008 – 2026 A metal world and a public to win

Jim Bell does not just build cameras. He shares the images with the public, led for twelve years the world’s largest space education and advocacy organization, and set off for a metal asteroid.

The Planetary Society

From 2008 to 2020 he was president of The Planetary Society, the organization founded by Carl Sagan, which his university describes as the world’s largest public space education and advocacy organization. The American Astronomical Society awarded him the Carl Sagan Medal for public communication in planetary science. He has published many popular books: Moon 3-D, The Space Book, The Interstellar Age on the forty years of Voyager, The Earth Book, Hubble Legacy, Discovering Mars with William Sheehan, The Art of the Cosmos. A main-belt asteroid bears his name: 8146 Jimbell.

Psyche, heavy metal

He is also deputy principal investigator of the Psyche mission, led by his university, and head of its imager. Psyche is to study a metal-rich asteroid, perhaps the partial core of a planetary building block. The mission’s lead, Lindy Elkins-Tanton, describes his humor: about Psyche, he reportedly declared that it was heavy metal and that everyone had to get piercings and mohawks. She also describes a tattoo around his upper arm with the symbols of every solar system body he had been on a mission to visit.

“All we know,” he said in 2021, “is that the reality of Psyche is going to be even weirder and more beautiful than we can imagine.” The spacecraft launched on October 13, 2023. On December 4, its two cameras took their first 68 images, in the constellation Pisces: “These initial images are only a curtain-opener.” In May 2026, Psyche flew past Mars and took thousands of images to calibrate its cameras, with help from Perseverance and other spacecraft. It is due to reach its asteroid in August 2029.

Sources: Arizona State University, Jim Bell’s “About” page (Planetary Society presidency 2008–2020, “the world’s largest public space education and advocacy organization,” Carl Sagan Medal, books, 8146 Jimbell); web search summarizing his Planetary Society profile (Sagan Medal in 2011); NASA, “NASA’s Psyche Mission Has a Metal World in Its Sights,” June 11, 2019 (deputy principal investigator); NASA, “On a Mission” podcast, season 2, episode 6, November 12, 2019 (Lindy Elkins-Tanton’s account, “heavy metal,” the tattoo); NASA/JPL, “Science of Psyche…,” October 4, 2021 (quotation); NASA, “NASA’s Psyche Delivers First Images and Other Data,” December 5, 2023 (October 13, December 4, 68 images, Pisces, quotation); NASA, “NASA’s Psyche Mission Aces Mars Flyby, Targets Metal-Rich Asteroid,” May 19, 2026 (thousands of images, Perseverance, August 2029).