NASA is developing a new instrument for finding distant exoplanets — called the Wide Field Infrared Survey Telescope, or WFIRST. It's going to locate not only small and distant exoplanets, but also a wider variety of cosmic bodies, like brown dwarfs and black holes.
WFIRST to unveil NASA's microlensing technique
Most of the instruments used to detect and study exoplanets, like NASA's exoplanet seeking satellite TESS, work with what's called the transit method. This is a process according to which telescopes point to distant stars looking for periodic dimming in brightness, which is interpolated to confirm the presence of a planet passing between the telescope and the star — in an event called a transit.
WFIRST breaks with this convention by adding another method to the mix, called microlensing. When a small planet passes before its host star, its relatively small gravitational force still bends the star's light in a way we can see from a great distance. This technique only works with a rare level of precise alignment, but when it happens the signal is stronger than those received via the transit method, allowing for the detection of even more distant planets.
"Microlensing signals from small planets are rare and brief, but they're stronger than the signals from other methods," said David Bennet, leader of a gravitational microlensing group at NASA's Goddard Space Flight Center, in a statement. "Since it's a one-in-a-million event, the key to WFIRST finding low-mass planets is to search hundreds of millions of stars."
"Trying to interpret planet populations today is like trying to interpret a picture with half of it covered," said Matthew Penny, an assistant professor of astronomy and physics at Louisiana State University in Baton Rouge who also led a study to envision WFIRST's microlensing survey potential, reports Yahoo! Finance.
WFIRST will expand our knowledge beyond exoplanets
He added that WFIRST's microlensing survey will do more than advance our knowledge of planetary systems. "It will also enable a whole host of other studies of the variability of 200 million stars, the structure and formation of the inner Milky Way, and the population of black holes and other dark, compact objects that are hard or impossible to study in any other way," said Penny.
NASA is pushing new advances in every arena of space travel and exploration, but new styles of exoplanet detection like that of the WFIRST telescope will take the techniques we gain from hunting exoplanets beyond alien systems — to better grasp the Milky Way, wilding black holes, and other astounding objects throughout the universe.