From groundbreaking work in searching our galaxy for potentially life-bearing exoplanets to researching gamma ray bursts, which are perhaps the most powerful phenomena in the universe, scientists at CEHW and IGC have made countless discoveries and observations thanks to the state-of-the-art facilities and world-class research opportunities made possible by this University. Thus, it is not uncommon to hear Penn State’s name mentioned in the world of astronomy and astrophysics. The Center for Exoplanets and Habitable Worlds and the Institute for Gravitation and the Cosmos, both of which were founded at Penn State, are at the forefront of space exploration and making considerable advancements in the way we understand the universe.
Center for Exoplanets and Habitable Worlds
Now in its 10th year, the Center for Exoplanets and Habitable Worlds (CEHW) is beginning to write the next chapter in its already considerable contributions to planetary and stellar research. Focused on the observation and detection on planets outside of our solar system—some of which may contain the necessary components to sustain life—CEHW has enabled Penn State to become one of the leading exoplanet-research institutions in the world.
According to Eric Ford, director of CEHW, Penn State was among the first universities to begin research on habitable worlds and influenced what is now a rapidly growing field of science. The Hobby-Eberly Telescope (HET), the world’s fourth largest optical telescope and a collaboration between Penn State and several other institutions, has contributed greatly to the findings we see today. With the HET, researchers in CEHW are searching for exoplanets, using the Doppler method—measuring the subtle change in color of a star’s infrared spectra as it is pulled by an orbiting planet. CEHW researchers have started exploring exoplanet atmospheres, an early step along the road to searching for signs that the planets might contain the molecules necessary to sustain Earthlike life.
“We are interested not just in detecting exoplanets,” Ford said, “but also in characterizing them and understanding how they formed, which of them may be habitable, how common potential habitability is, and where we should look to find other exoplanets. It’s quite exciting as we see the progress towards the characterization of other planets.”
As for the future, the scientists of CEHW are well prepared. CEHW researchers have made technological advances that are increasing the number of exoplanets characterized using the radial velocity method. Penn State will soon be studying exoplanets with two next-generation spectrographs built at Penn State. The University has recently sent the Habitable Zone Planet Finder spectrograph (HPF) to the HET and is in the final stages of constructing the NN-EXPLORE Exoplanet Investigations with Doppler Spectroscopy spectrograph (NEID) for the WIYN telescope. These new spectrographs will be used to search for exoplanets and to characterize their masses and orbits.
Institute for Gravitation and the Cosmos
In the realm of fundamental physics, mathematics, relativistic astrophysics, and philosophy of science, the Institute for Gravitation and the Cosmos (IGC), which is celebrating its 25th year, has made historic advances in the study of geometry, gravitational waves, quantum gravity, and particle astrophysics. The study of gravitational waves, in particular, has proved to be a huge leap at the institute and in the worldwide community of multimessenger astrophysics. The first discoveries firmly established the existence of black holes and confirmed Einstein’s general relativity in the strong field regime. A more recent discovery of merging neutron stars was followed by a large number of astronomical observatories and shed light on the birth of heavy elements like gold and platinvum.
Abhay Ashtekar, director of IGC, notes how the institute founded the field of loop quantum gravity to address the most exciting challenge on the frontier of theoretical physics: unifying general relativity and quantum gravity. Loop quantum gravity has led to new insights into the true nature of the big bang and black holes. Other significant discoveries at IGC have increased our understanding of gamma-ray bursts and the mechanisms that form them, and helped to facilitate the discovery of gravitational waves.
The scientists at IGC are pioneers in multimessenger astrophysics, particularly through Penn State’s Astrophysical Multimessenger Observatory Network (AMON). In collaboration with an expanding list of observatories worldwide, AMON facilitates research of high-energy signals such as cosmic rays, gravitational waves, neutrinos, gamma rays, and X-rays from across the universe.
Continuing to lead this frontier area of fundamental science through the next 25 years won’t be an easy feat, but Ashtekar and his colleagues at IGC are ready. As technology continues to rapidly develop in astronomy, and as scientists are gaining depth in their understanding of physics, we can expect more of the universe’s secrets to slowly start to be uncovered.
“Just as when Galileo raised a telescope and looked at the skies the whole worldview changed,” Ashtekar said, “we fully expect our view of the universe as a whole will change with multimessenger astrophysics.” IGC’s scientists are poised to advance our understanding of some of the cosmos’s biggest mysteries—unseeable things such as dark energy and dark matter, as well as the quantum nature of black holes—including answering lingering questions raised by the late theoretical physicist Stephen Hawking. Ashtekar believes many of these questions will be answered within the next decade. “Our understanding of the universe, our knowledge of the universe, the things we take for granted about the universe 25 years from now,” he said, “will be quite different than what we know today.”