NASA Supercomputer Assists The Hunt For Exomoons

Artist's impression of a hypothetical Earth-like moon around a Saturn-like exoplanet. Image Credit: NASA

Artist’s impression of a hypothetical Earth-like moon around a Saturn-like exoplanet. Image Credit: NASA

February 2, 2015 – A team of 21st-century explorers working for the Hunt for Exomoons with Kepler (HEK) project, based at Harvard University, are searching for exomoons using data from NASA’s Kepler mission and the Pleiades supercomputer at the NASA Advanced Supercomputing (NAS) facility at NASA’s Ames Research Center.

The discovery of exomoons—moons situated beyond our own solar system—would add to the growing list of celestial objects detected by the Kepler telescope that could potentially harbor life in some form.

In the quest to find the first exomoon, HEK astronomers led by David Kipping at the Harvard-Smithsonian Center for Astrophysics have devised a unique, systematic computational approach that requires 5.2 million processor hours on Pleiades. Using their in-house LUNA light curve modeling algorithm and a massively parallel sampling algorithm called MultiNest, the project team simulates billions of possible star-planet-moon configurations and compares the results to the actual Kepler data to look for a good match. So far, the team has surveyed 56 of about 400 identified Kepler planet candidates that could have a detectable exomoon.

Surveying the remaining 340 planet candidates would require about 50,000 hours of processing time per object and would take nearly a decade to complete on smaller computers. Utilizing NASA’s powerful Pleiades system—which performs over 3 quadrillion calculations per second—will speed up this computationally expensive process, reducing the processing time to 30,000 hours per object.

Over the next two years, the team will survey the remaining candidates for exomoons by performing photo-dynamical analysis of the public data from Kepler, consuming about 10 million processor hours on Pleiades. Their results will be used to determine the occurrence rate of Earth-like moons.

Since Kepler launched in March 2009, a team of University of Colorado students and Laboratory for Atmospheric and Space Physics (LASP) professionals have controlled the spacecraft from the LASP Mission Operations Center in Boulder, Colorado. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The original Kepler mission conducted a survey of approximately 150,000 stars in the Milky Way galaxy for Earth-sized planets with the potential to support life. To date, Kepler’s data has offered scientists an assortment of more than 4,000 candidate planets for further study — the 1,000th of which was recently verified.

After the second wheel of Kepler’s guidance control system failed last year during the spacecraft’s extended mission, engineers devised an ingenious way to repurpose Kepler for the K2 mission and continue its search of the cosmos for other worlds. A team of scientists and engineers crafted a resourceful strategy to use pressure from sunlight as a “virtual reaction wheel” to help control the spacecraft. The resulting K2 mission not only continues Kepler’s planet hunt, but has also expanded the search to bright nearby stars that harbor planets.

For more information about the HEK Project, visit: http://www.cfa.harvard.edu/HEK/index.html