Welcome to Space Physics at Princeton
The Space Physics group in the Department of Astrophysical Sciences:
- Educates Princeton University undergraduate and graduate students through hands-on work in an active space instrument laboratory and with scientific data from space
- Conceives, designs develops, calibrates, and flies cutting-edge space instrumentation on NASA missions
- Analyzes space data from the Sun and Solar Corona through to the Solar Wind and terrestrial and planetary magnetospheres, including the global heliosphere and its interaction with the local interstellar medium
- Discovers scientific secrets of our space environs through integrated observations, data analysis, and theoretical understanding
We are the lead institution for numerous NASA Heliophysics missions and instruments that Prof. David J. McComas serves as the principal investigator for:
Interstellar Mapping and Acceleration Probe (IMAP) mission – under development and launching in 2025 to explore the details of particle acceleration and the Sun’s interaction with the local interstellar medium;
Parker Solar Probe (PSP), Integrated Science investigation of the Sun (ISʘIS) instrument suite – launched 8/12/2018 to measure energetic particles as close in as nine solar radii from the Sun’s surface;
Interstellar Boundary Explorer (IBEX) mission – launched in 2008 and still exploring the boundaries of our heliosphere and its interaction with the local interstellar medium;
New Horizons, Solar Wind Around Pluto (SWAP) instrument – launched in 2006, measured the plasma environments of Pluto and the Jovian magnetosphere and continues to make unprecedented observations of interstellar pickup ions;
Advanced Composition Explorer (ACE), Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument – launched in 1997 and still providing solar wind data from the Sun-Earth Lagrangian point (L1);
Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission – returned the first stereo imaging of the Earth’s dynamic magnetosphere (operational from 2008-2017);
Ulysses, Solar Wind Observations Over the Poles of the Sun (SWOOPS) instrument – discovered the three-dimensional structure of the solar wind from the first and only mission to fly over the poles of the Sun (operational from 1990 - 2009).
Research News
The Parker Solar Probe (PSP) spacecraft has transited the innermost regions of the zodiacal cloud and detects impacts to the spacecraft body via its electric field instrument. Multiple dust populations have been proposed to explain the PSP dust impact rates. PSP’s unique orbit allows us to identify a region where the impact rates are likely…
This a novel and broadened theoretical framework of special relativity, which is unified for describing entropies and velocities, and consistent with both thermodynamics and kinematics. The new theory is not to be confused with some relativistic adaptation of thermodynamics; instead, it is a unification of the physical disciplines of…
We develop the kappa-tail fitting technique, which analyzes observations of power-law tails of distributions and energy flux spectra, and connects them to theoretical modeling of kappa distributions, to determine the thermodynamics of the examined space plasma. In particular, we (i) construct the associated mathematical formulation; (ii) prove…
The paper shows the thermodynamic nature of the evolution of the pickup ion (PUI) distributions through their incorporation and subsequent expansion as the solar wind moves outward through the heliosphere. In particular, the PUI expansive cooling is connected to thermodynamic polytropic processes and the thermodynamic kappa parameter…
David McComas, Princeton University’s vice president for the Princeton Plasma Physics Laboratory (PPPL), will conclude his PPPL leadership role to focus on the successful completion and launch of NASA’s Interstellar Mapping and Acceleration Probe (IMAP). McComas is the principal investigator for the IMAP mission, which is scheduled to launch…
Juno performed two close flybys of Io and found enhanced field‐aligned proton fluxes are absorbed by Io. These protons are absorbed at mass input rates comparable to previous estimates for hydrogen losses from Io, hence Jupiter is likely the source of hydrogen at Io. The conditions necessary for this to occur are: (a) formation of Alfvén waves…
This paper reveals the universality of the particle energy distribution function, despite the arbitrariness that characterizes the generalized thermodynamic entropic function. We show that the canonical distribution, that is, the distribution function that maximizes this entropy under the constraints of canonical ensemble, is always the same…
Thousands gathered in Princeton’s Palmer Square on Monday, 4/8/24, for a community viewing of the partial solar eclipse.
Volunteers from the Space Physics Group and the Department of Astrophysical Sciences joined the Council on Science and Technology and the Amateur Astronomers Association of Princeton to answer questions and…
On March 15, 2024, at Princeton University, Lengying Khoo, Tejaswita Sharma, and Kimberly Rogan from the Space Physics Group shared information about the IMAP mission with over 800 middle school and high school students at the Young Women’s Conference in STEM. The conference, hosted by the U.S. Department of Energy’s Princeton Plasma…
Solar energetic particle (SEP) events have been observed by the Parker Solar Probe (PSP) spacecraft since its launch in 2018. These events include sources from solar flares and coronal mass ejections (CMEs). The ISOIS instrument suite on board PSP is measuring ions over energies from ~20 keV nucleon-1 to 200…