NASA to Launch Wide-Field IR Survey Telescope

NASA’s Agency Program Management Council has announced the decision to move forward with the Wide Field Infrared Survey Telescope (WFIRST), a six-year mission set to launch from Cape Canaveral, Fla., in the mid-2020s.

WFIRST is the agency's next major astrophysics observatory, following the launch of the James Webb Space Telescope in 2018. The observatory will survey large regions of the sky in near-infrared (NIR) light to answer fundamental questions about the structure and evolution of the universe, and expand the knowledge of planets beyond our solar system, known as exoplanets.

A rendering of WFIRST with an image of the spiral galaxy NGC 2441. A type-Ia supernova, SN1995E, is circled in red. Courtesy of NASA/European Space Agency/Hubble Space Telescope/Nick Rose.

The 2.4-m telescope will have a primary mirror the same size as that of the Hubble Space Telescope with a field of view that is 100 times larger than Hubble's IR instrument. It will measure light from an estimated billion galaxies.

WFIRST will carry a wide-field instrument for surveys, and a coronagraph instrument designed to block the glare of individual stars and reveal the faint light of planets orbiting around them. By blocking the light of the host star, the coronagraph will enable detailed measurements of the chemical makeup of planetary atmospheres. Comparing these data across many worlds will allow scientists to better understand the origin and physics of these atmospheres, and search for chemical signs of environments suitable for life, NASA said.

"WFIRST is designed to address science areas identified as top priorities by the astronomical community," said Paul Hertz, director of NASA's Astrophysics Division in Washington. "The wide-field instrument will give the telescope the ability to capture a single image with the depth and quality of Hubble, but covering 100 times the area. The coronagraph will provide revolutionary science, capturing the faint, but direct images of distant gaseous worlds and super-Earths."

The telescope's sensitivity and wide view will enable a large-scale search for exoplanets by monitoring the brightness of millions of stars in the crowded central region of our galaxy. The survey will net thousands of new exoplanets similar in size and distance from their star as those in our own solar system, complementing the work started by NASA's Kepler mission and the upcoming work of the Transiting Exoplanet Survey Satellite.

Employing multiple techniques, astronomers also will use WFIRST to track how dark energy and dark matter have affected the evolution of our universe. Dark energy is a mysterious, negative pressure that has been speeding up the expansion of the universe; dark matter is invisible material that makes up most of the matter in our universe.

By measuring the distances of thousands of supernovae, astronomers can map in detail how cosmic expansion has increased with time. WFIRST also can precisely measure the shapes, positions and distances of millions of galaxies to track the distribution and growth of cosmic structures, including galaxy clusters and the dark matter accompanying them.

WFIRST is managed at NASA’s Space Flight Center in Greenbelt, Md., with participation by the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprising members from U.S. research institutions across the country, such as the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California Berkeley.

Berkeley researcher Saul Perlmutter will lead a scientific team to analyze WFIRST supernovae observations to explore dark energy. Courtesy of Roy Kaltschmidt/Berkeley Lab.

Saul Perlmutter, a Berkeley Lab astrophysicist and UC Berkeley astrophysics professor who shared the 2011 Nobel Prize in physics for his research team's discovery that our universe is expanding at an accelerating rate, will lead a 29-member scientific team, from 15 institutions, that will plan for the use of WFIRST supernovae observations to explore dark energy.

"The question that was raised with the 2011 Nobel Prize is, 'Why is the universe's expansion accelerating?'" Perlmutter said. “We think that this detailed expansion history is our current best shot as to getting a hint at which explanations for the accelerating expansion of the universe are true: If it's dark energy, is it constant in time or changing over time? And if it's not dark energy, are there revisions needed in Einstein's theory of general relativity … to best explain this acceleration?”

WFIRST is slated to launch in the mid-2020s. The observatory will begin operations after travelling to a gravitational balance point known as Earth-Sun L2, which is located about one million miles from Earth in a direction directly opposite the Sun.

The Wide-Field Infrared Survey Telescope (WFIRST) is an upcoming space telescope designed to perform wide-field imaging and spectroscopy of the IR sky. One of WFIRST's objectives will be looking for clues about dark energy — the mysterious force that is accelerating the expansion of the universe. Another objective of the mission will be finding and studying exoplanets. Courtesy of NASA.