First Exoplanets Discovered Using Sunlight as Virtual Reaction Wheel

In a remarkable turn of events, scientists and engineers have successfully used pressure from sunlight as a 'virtual reaction wheel' to control NASA's planet-hunting Kepler spacecraft, leading to the discovery of the first exoplanet found using its new mission - K2.

The journey began in May 2013 when data collection during Kepler's extended prime mission came to an end due to the failure of the second of four reaction wheels. These reaction wheels are crucial for stabilizing the spacecraft and enabling precise brightness measurements, which are necessary for detecting exoplanets. The smaller the planet, the weaker the dimming, making precision a top priority.

To overcome this challenge, astronomers and engineers devised an ingenious plan to repurpose Kepler for the K2 mission. By harnessing sunlight as a virtual reaction wheel, they were able to control the spacecraft's pointing and maintain steady precision.

The first exoplanet discovered using this innovative approach is HIP 116454b, which orbits a star located 180 light-years from Earth in the constellation Pisces. With a diameter of 2.5 times that of our own planet, HIP 116454b follows a close, nine-day orbit around a star that is smaller and cooler than our sun. Unfortunately, this makes the planet too hot for life as we know it.

The discovery was confirmed using measurements taken by the HARPS-North spectrograph at the Telescopio Nazionale Galileo in the Canary Islands. These readings captured the wobble of the star caused by the gravitational tug of the exoplanet as it orbits.

Lead researcher Andrew Vanderburg, a graduate student at Harvard-Smithsonian Center for Astrophysics, studied publicly available data collected during a test of K2 in February 2014. He expressed excitement about the discovery, saying, 'Today, thanks to an innovative idea and lots of hard work by the NASA and Ball Aerospace team, Kepler may well deliver the first candidates for follow-up study by the James Webb Space Telescope to characterize the atmospheres of distant worlds and search for signatures of life.'

Paul Hertz, NASA's astrophysics division director, echoed Vanderburg's sentiments, noting that the possibility of a scientifically productive mission for Kepler after its reaction wheel failure was not initially part of the conversation. However, through perseverance and creativity, astronomers and engineers were able to breathe new life into the spacecraft, leading to this groundbreaking discovery.

The K2 mission marks a significant milestone in NASA's quest to explore the cosmos for other worlds and potentially discover signs of life beyond Earth. As we continue to push the boundaries of space exploration, it is remarkable stories like this one that remind us of the power of human innovation and ingenuity.

First exoplanets discovered