Stuart Bale | Research UC Berkeley

Research Expertise and Interest

experimental space physics, plasma astrophysics, solar physics, low frequency radio astronomy

Research Description

Stuart Bale is interested in plasma astrophysics from the experimental point of view. Much of the universe is in the plasma state and we are just coming to appreciate the role of plasma dynamics and magnetic fields in the large-scale evolution of astrophysical systems. However, many of the fundamental processes are poorly understood and can only be studied in a limited parameter regime in the laboratory. Examples are magnetic reconnection, collisionless shocks, plasma turbulence, and solar/stellar wind generation and evolution.

His research is focused on developing experiments to understand these processes and, in particular, how microscale, kinetic phenomena, affect large-scale plasma dynamics.

He is increasingly interested in low frequency (LF) radio astronomy. Measurements below 20 MHz are difficult to make on Earth and my group has developed a LF radio polarimetry instrument for space. The spectrum below 20 MHz is dominated by the galactic synchrotron spectrum and discrete sources (including the Sun and outer planets). However below this bright foreground is a faint cosmological signal associated with the thermal physics of the early universe.

His research group at the Space Sciences Laboratory (SSL) develops, builds, and operates space-borne experiments to study in situ the plasma processes active in astrophysical, heliospheric, and magnetospheric systems. These experiments are flown on NASA and ESA spacecraft missions and are often developed as balloon and sounding rocket payloads. Opportunities exist for student to participate in the design, development, and science on a wide variety of projects at SSL.

In the News

Stuart Bale Awarded the 2025 Arctowski Medal

Bale has revolutionized our understanding of the energization of and heat transport in the solar wind.

a satellite hovering over an angry red sun

Parker Solar Probe Flies Into the Fast Solar Wind and Finds Its Source

Findings reveal details that are lost as the wind exits the corona as a uniform blast of charged particles.

Parker Solar Probe shown against yellow sun

Parker Solar Probe Touches the Sun — a First for Any Spacecraft

or the first time in history, a spacecraft has touched the sun. NASA’s Parker Solar Probe, which carries instruments built at UC Berkeley, flew through the sun’s upper atmosphere — the corona — for a few hours on April 28, 2021, sampling particles and magnetic fields for the first time from one of the hottest places in the solar system.

Parker probe traces solar wind to its source on sun’s surface

A year ago, NASA’s Parker Solar Probe flew closer to the sun than any satellite in history, collecting a spectacular trove of data from the very edge of the sun’s million-degree corona. Now, that data has allowed solar physicists to map the source of a major component of the solar wind that continually peppers Earth’s atmosphere, while revealing strange magnetic field reversals that could be accelerating these particles toward our planet.

Scientists scramble to build payload for 2021 moon landing

Scavenging spare parts and grabbing off-the-shelf hardware, University of California, Berkeley, space scientists are in a sprint to build scientific instruments that will land on the moon in a mere two years.

the solar probe flying over the surface of the sun

Space probe to plunge into fiery corona of the sun

Instruments built by UC Berkeley space scientist will fly aboard the Parker Solar Probe to explore the hot atmosphere of the sun.

Fierce solar magnetic storm barely missed Earth in 2012

According to University of California, Berkeley, and Chinese researchers, a rapid succession of coronal mass ejections — the most intense eruptions on the sun — sent a pulse of magnetized plasma barreling into space and through Earth’s orbit.

2 men site in front of a computer screen in a lab.

Scrutinizing Space Storms for a Calmer Life on Earth

Thomas Immel and his team at the Space Sciences Lab will design, build and operate two instruments and oversee development of two others to be loaded on a solar-powered satellite for a two-year science mission tentatively set to launch in 2017.

NASA Selects Investigations for First Mission to Encounter the Sun

NASA has chosen a UC Berkeley experiment and three others to fly aboard Solar Probe Plus, a satellite scheduled for launch in 2018 to explore the sun's million-degree atmosphere. Physicist Stuart Bale, director of the Space Sciences Lab, will lead development of instruments to detect radio emissions, magnetic fields, shock waves and dust as the spacecraft plunges into the sun.

Featured in the Media

Please note: The views and opinions expressed in these articles are those of the authors and do not necessarily reflect the official policy or positions of UC Berkeley.

December 5, 2019

NASA's Parker Solar Probe Is Unlocking the Sun's Mysteries

New York Times

Kenneth Chang

NASA's Parker Solar Probe has not only come closer to the sun than any prior mission from Earth, but it's also reached the fastest speed of any man-made vehicle. Carrying scientific instruments built and monitored by Berkeley researchers, the mission is measuring electric and magnetic fields in the sun's atmosphere, providing stunning new insights about the sun and solar winds, or "space weather," which can disrupt radio communications, interfere with GPS systems, and zap electrical grids, and endanger astronauts. Physics professor Stuart Bale, one of the Space Sciences Laboratory's principal investigators working on the project, compares studying solar winds from Earth to observing a waterfall from halfway down. "The water is always flowing past us," he says. "It is very turbulent, chaotic, unstructured. And we want to know what is the source of the waterfall, what's at the top. Is there an iceberg melting up there? Is there a sprinkler system? A lake? ... We want to know the source of the water, what's at the top." For more on this, see our press release at Berkeley News. Stories on this topic have appeared in nearly 1,000 sources around the world, including the Washington Post (AP), EarthSky, The Atlantic, CNN (link to video), and NPR's All Things Considered (link to audio).

FullStory (*requires registration)

December 4, 2019

Berkeley tools aboard NASA's Solar Probe help find the source of solar wind

Mercury News

Lisa M. Krieger

Nearly 90 million miles away and practically within reach of the sun, a collection of Berkeley-made scientific instruments aboard NASA's Parker Solar Probe is measuring electric and magnetic fields in the sun's atmosphere, providing stunning new insights, not just about solar energy but physics itself. "Our data are spectacular," says physics professor Stuart Bale, one of the Space Sciences Laboratory's principal investigators working on the project. "What we're seeing is the large scale magnetic structure of the sun, and on top of that are impulsive magnetic events that we think are originating far below us in the corona -- probably responsible for heating the solar wind itself." The project aims to better understand "space weather," which can wreak havoc on Earth, including disrupting radio communications, interfering with GPS systems, and zapping electrical grids. "If we knew something big was coming, it's hard to see that we could deflect it or anything," Professor Bale says. "But one could imagine shutting down parts of the power grid, isolating parts of the communication system, shutting down satellites that might be vulnerable. ... There are things you could do to protect the systems." For more on this, see our press release at Berkeley News. Stories on this topic have appeared in hundreds of sources around the world, including Nature, The Guardian, Newsweek, and Mail on Sunday (UK).