At the fertile interface between particle physics and astronomy, the field of particle astrophysics explores the cosmos using particle physics techniques and the subatomic world using astronomical observations. Our department is engaged in a bold synergistic (theoretical and experimental) approach to understanding high energy processes in the universe. Our faculty are prominent participants in multiple major international projects that make observations using extremely high energy protons and nuclei, neutrinos, gamma rays, X rays, and gravitational waves. These projects include the Pierre Auger Cosmic-Ray Observatory, the IceCube Neutrino Observatory, the ANITA neutrino balloon experiment, the Askaryan Radio Array neutrino experiment, the Swift Gamma-Ray Burst Explorer satellite, the Chandra X-ray Observatory, the XMM-Newton X-ray Observatory, the Laser Interferometric Gravitational-wave Observatory, the North American Nanohertz Observatory for Gravitational waves, the HAWC TeV Gamma-ray observatory, the International X-ray Observatory, the Large Synoptic Survey Telescope, the X-ray observatory Athena, the Fermi satellite, the VERITAS high-energy Gamma-ray Observatory, the High Energy Light Isotope eXperiment high-altitude balloon, and the Laser Interferometer Space Antenna project. A few years ago we made the strategical decision to expand our particle astrophysics program to include dark matter experimentalists. We now actively participate in the Large Underground Xenon (LUX) dark-matter experiment, and we play a leading role in the construction and commissioning of the cryogenics and liquid Xenon systems for the next-generation dark-matter experiment, LUX-ZEPLIN (LZ). The Penn State group plays leading roles on the development of these instruments and on the analysis of the rich data harvest from them. Further information can be found at the web-page of the Institute for Gravitation and the Cosmos.