Recently, the Kepler mission announced the discovery of 1,284 new planets. The announcement represents the most planets ever discovered at a single time, and more than doubles the total number of planets discovered by the Kepler telescope. Launched into space by NASA in 2009, Kepler’s goal is to determine how many Earth-sized planets reside in or near habitable zones, and estimate how many of such planets might exist in the Milky Way.
When Kepler observes the periodic dimming of a host star, presumably due to a planet in transit, the potential object is added to a long list of planet candidates. Previously, candidates required individual validation via ground based observations. With this announcement, Kepler introduces a new likelihood technique that allows the mission to analyze candidates and make discoveries in bulk. This new statistical method was only achievable because Kepler already had a sufficiently large repository of discovered planets. The newly announced collection of planets will serve as an invaluable dataset for future missions.
With the announcement, the Kepler also adds 9 new planets to the list of “Goldilocks planets.” At the most basic level, if a planet’s surface can contain liquid water, the planet is considered to be in a habitable zone. Kepler roughly estimates a planet’s temperature by considering the distance between the planet and its host star, as well as the size and strength of the host star itself. However, Kepler is not capable of taking a planet’s atmosphere into account. The habitable zone thus represents a fuzzy boundary, in which such planets may or may not be habitable.
Nevertheless, the success of the Kepler mission is remarkable. Since 2009, a number of technical difficulties have befallen the telescope. The telescope’s steering mechanism has been broken since 2012, and Kepler briefly entered emergency mode just last month. The telescope briefly lost contact with Earth, and many scientists at NASA feared its illustrious career was over. Kepler is scheduled to continue taking data for the next year, and TESS, its successor, will replace Kepler once it retires. Scientists expect a bright future filled with many more discoveries from the two telescopes.
Acknowledgments: Many thanks to Carl Schmidt, a research associate at Laboratoire Atmosphères, Milieus, Observations Spatiales (LATMOS) in France, and Lauren Woolsey, a PhD student working in the Astronomy Department at Harvard.
“Kepler Spacecraft Rakes in Nearly 1300 Planets” – Nature News
“Kepler Spacecraft in Emergency Mode” – Nature News
“Kepler Finds 1234 New Planets” – The New York Times
“False Positive Probabilities for all Kepler Objects of Interest: 1284 Newly Validated Planets and 428 Likely False Positives” – The Astrophysical Journal
Managing Correspondent: Karri DiPetrillo