Johns Hopkins APL Researchers Will Play Leading Role in James Webb Space Telescope’s First Year
Image of NASA’s fully integrated James Webb Space Telescope in Northrop Grumman’s cleanroom facilities in Redondo Beach, California. Slated for launch in October 2021, Webb will be the largest telescope ever launched into space.
Credit: NASA/Chris Gunn
Wed, 04/07/2021 - 13:08
A dozen proposals submitted by researchers from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, have been selected as part of the NASA James Webb Space Telescope’s Cycle 1 General Observers program, which provides the world’s astronomical research community with access to the telescope during its first year of operation.
Announced March 30 by NASA officials, the proposals — three of which will be led by APL researchers — are just a handful of the 286 selected from a stack of more than 1,000 submitted by researchers last November. Together, the hundreds of projects fill roughly 6,000 hours of the telescope’s first year of operation, called Cycle 1.
With its enormous 21.3-foot (6.5-meter) primary mirror and sensors for capturing images and spectra in near-to-mid-infrared light, the James Webb Space Telescope will be the largest telescope ever launched into space, capable of funneling more light, and with higher resolution, than any telescope before it.
The selected proposals will take advantage of these superlatives, investigating subjects that span the entire cosmos, from planets, moons and asteroids right here in our solar system to exoplanets, supermassive black holes and galaxies that date to the beginning of the universe.
Andy Rivkin, a planetary astronomer at APL, leads one of those projects. His team will employ the telescope’s capabilities to better understand the compositions of several primitive asteroids, including mapping the surfaces of three of them. These asteroids include the near-Earth object Phaethon, which exhibits comet-like activity and will be the destination of the upcoming Japanese DESTINY+ mission; and dwarf planet Ceres, the largest object in the asteroid belt, which NASA’s Dawn spacecraft studied up close from 2015 to 2018. Rivkin’s group will be developing a technique to use scattered light from the asteroids to reveal new details about each of these bodies.
“Our targets are survivors from the first stages of solar system history and contain the ingredients that make planets habitable,” Rivkin explained. “Webb will allow us to measure water-bearing minerals that we cannot detect from Earth due to our atmosphere, and our work will allow a wider range of objects — whether in this solar system or others — to be usefully observed by Webb.”
Artist’s concept of the James Webb Space Telescope in space. Webb will be sensitive to near-to-mid infrared light, which requires it to be cold and isolated from heat sources that could generate infrared background “noise.”
Looking far beyond our solar system, APL astrophysicist Kevin Stevenson and exoplanet researcher Jacob Lustig-Yaeger aim to uncover whether rocky planets around M-dwarf stars —small red stars that make up the majority of stars in our corner of the Milky Way galaxy — have atmospheres. It’s a characteristic that is critical to determining their habitability but that to date has remained a contentious unknown. Studying five of these terrestrial exoplanets that orbit the nearest red dwarf stars to Earth, the team will reveal exactly which of these exoplanets have atmospheres as well as their compositions.
“We’re looking for evidence of a cosmic shoreline, a universal divide between planets with and without atmospheres that is based on their physical characteristics,” Stevenson said. “We see a clear separation for bodies within our own solar system, so now we’ll be testing this theory for M-dwarf systems.” Once the team can predict which planets are most likely to have atmospheres, he added, they can start the time-consuming process of searching for detectable signs of life within those atmospheres.
In another exoplanet vein, Laura Mayorga, an exoplanet astronomer, and her co-leads from NASA’s Jet Propulsion Laboratory and Cornell University will build upon infrared observations made by NASA’s Spitzer Space Telescope in 2016 of exoplanet HD 80606b, a “hot Jupiter” that swings an uncomfortable 2.8 million miles from its star — about 1/10th the distance of Mercury when it’s closest to the Sun — as it follows a highly elliptical orbit. Using Webb’s mid-infrared camera and spectrograph, the team will capture roughly 20 hours of the gas giant’s orbit, focusing specifically on when it passes closest to the star so they can watch the planet’s atmosphere as it rapidly heats up by 1,500 degrees Fahrenheit (815 degrees Celsius) only to then quickly cool down.
“Eccentric planets like HD 80606b are ideal places to test our understanding of atmospheric dynamics and chemistry because of these changes,” Mayorga explained. They reveal details about how planetary atmospheres and their compositions respond to sudden inputs of heat. “It’s like when you used to poke a bug with a stick, trying to make it move. We can’t do that with planets, but stars sure can.”
The James Webb Space Telescope is slated to launch in October 2021, riding aboard an Ariane 5 rocket. It will begin observations in 2022 from Earth’s L2 Lagrange point, around 930,000 miles (1.5 million kilometers) away from Earth, opposite the direction of the Sun. Science observations will begin following a six-month commissioning period after launch, according to NASA.
The Applied Physics Laboratory, a not-for-profit division of The Johns Hopkins University, meets critical national challenges through the innovative application of science and technology. For more information, visit www.jhuapl.edu.