Did the universe have a beginning? When was it, and what was it like? What are the stars? How distant are they? Why do they shine? How and when did the Earth form? Are there other worlds like Earth in the universe? Do they, too, have life?
We are living in a Golden Age of astronomy, where some of the oldest and most profound questions of philosophy long thought unanswerable are finding resolution.
The Apollo era created new interest and capabilities to answer these questions, and our next forays into the solar system led us to Venus, Mars and Jupiters moon, Europa. Our searches there have led to a scientific bounty, but also mild philosophical disappointment: so far, there is no sign of life on these worlds, or even conditions where much life from Earth could thrive.
Astronomers have not given up on these nearby bodies as potential hosts for life, but in 1992 a new avenue of discovery opened when Alexander Wolszczan, now an Evan Pugh professor of astronomy and astrophysics at Penn State, discovered planets orbiting the distant corpse of a burnt-out star the first exoplanets ever found outside our own solar system. Three years later, a Swiss team led by Michel Mayor, an astrophysicist and professor emeritus at the University of Geneva, discovered a giant gas planet like Jupiter orbiting scorchingly close to a nearby star. The methods that professors Wolszczan and Mayor helped to pioneer rapidly led to the discovery of many more of these distant planets. Over the next five years, the number of known exoplanets would approach 40 and astronomers would begin to measure the
sizes and compositions of these alien worlds.
The promise of research for finding Earth-like exoplanets has been realized rapidly over the past decade. Ever-smaller and balmier exoplanets have been continuously discovered in systems reminiscent of our own solar system. The past few years have been especially exciting, as the first exoplanets have been directly imaged, and exoplanets not much larger than Earth have been detected around the nearest stars.
The Kepler spacecraft has discovered thousands of exoplanets throughout our galaxy. As astronomers pore over this bounty they hope, and cautiously expect, to find the sort of exoplanet Kepler was specifically designed to reveal: an Earth-sized body (a terrestrial planet) around a sun-like star with an orbital distance implying a surface temperature compatible with liquid water (within the habitable zone). This discovery may be only months away.
And what of life? The search for extraterrestrial intelligence has been scouring the skies for radio and
Editors note:The Focus on Research column will highlight different research projects being conducted at Penn State. The bimonthly columns will feature the work of researchers from across all disciplines at the university.
Coming up next:A look at the new Center for Sport Concussion Research and Service at Penn State.
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