Issue 15 - May 2015 Exoplanets 20/20: A Message from the NASA Exoplanet Exploration Program Manager:
By Gary Blackwood

In 1995, astronomers started a revolution.

It took humans thousands of years to find the seven other planets in our solar system, and, not long ago, it seemed possible that was the limit of what we’d discover. Exoplanets—worlds orbiting stars beyond our own—were thought to be so distant, so tiny, and so hard to find that we’d never find them, even if they did exist.

Then, everything changed. Two astronomers, Michel Mayor and Didier Queloz, found a gas giant planet orbiting strangely close to the star 51 Pegasi. It was the first time a planet had been found orbiting another Sun-like star (the only previous exoplanet discovery had been around a dead star called a pulsar). Within just a few days, the discovery was confirmed by Geoffrey Marcy and Paul Butler. The race to find these so-called “exoplanets” was on, and practically every new discovery from then on overturned old assumptions about how the galaxy works and teased tantalizing new possibilities.

Today, 20 years later, exoplanets have become one of the most exciting and important topics in astronomy today. The Exoplanet Exploration Program is part of a growing movement toward exoplanet discovery, characterization, and the search for habitable worlds—and the search for life on these new worlds. Projects within the Program such as Kepler and the Large Binocular Telescope Interferometer are refining our knowledge of planetary occurrence rates and the prevalence of exozodiacal dust. A new NASA-NSF initiative, the Extreme Precision Doppler Spectrometer on Kitt Peak’s WIYN telescope, will perform follow-up measurements for Kepler and K2 discoveries and will perform precursor science for James Webb Space Telescope (JWST) transit spectroscopy and for Wide-Field Infrared Survey (WFIRST) direct imaging. The Astrophysics Division Director has charged the Program Analysis Groups (PAGs) to recommend large-scale missions to study in preparation for the 2020 Astrophysics Decadal Survey, and at least two of the concepts emphasize direct imaging of habitable exoplanets and the detection of biosignatures.

NASA is developing plans to celebrate the past 20 years of exoplanet exploration, and to imagine what the next 20 years will bring, through events and an online communications campaign. You can keep track of all public activities by visiting: We hope to join the entire exoplanet community in celebrating this truly amazing milestone.

What began with the single discovery of an incredibly hot, strange planet orbiting another star has now brought us to the cusp of answering ancient questions about our place in the galaxy and whether or not other worlds like ours exist. Twenty years ago, exoplanets, especially Earth-like ones, were the stuff of science fiction. Today, and thousands of discoveries later, astronomers are on the cusp of finding something people have dreamed about for thousands of years—another Earth.

Written with contributions from Josh Rodriguez