The James Webb Space Telescope, the most powerful telescope ever constructed, is completely booked to peer at other planets and the origins of the cosmos for more than a year after its expected October launch.
Scientists have planned 400 experiments that could uncover mysteries about the earliest galaxies, habitable planets, and even the birth of the universe.
“It’s a totally different beast,” said Nestor Espinoza, an astronomer who will be working on James Webb projects to examine planets outside our system. “We’re going to see stuff that we were not expecting, and that is what really has me super excited.”
The Webb telescope, named for NASA’s second administrator, James E. Webb, is years behind schedule and billions of dollars over budget, with the cost approaching $10 billion.
NASA hopes to launch it on Oct. 31 from Europe’s Guiana Space Center in French Guiana, a province of France in South America, aboard a European Ariane 5 rocket designed by France-based Arianespace. This is the European Space Agency’s contribution to the international programme, in which the Canadian Space Agency has participated.
The Hubble Space Telescope, which was launched in 1990, would be dwarfed by the Webb observatory. Webb’s primary mirror, or light-gathering surface, measures 21 feet wide, while Hubble’s measures 7.8 feet.
Webb’s solar shield is about the size of a tennis court and can keep the infrared instruments cool in vacuum. The telescope would orbit the sun at a distance of over one million miles from Earth.
According to NASA, Webb will probe the background of the universe for billions of light years. Its more powerful infrared instruments are intended to see more plainly and hundreds of millions of light years further than Hubble.
The galaxy GN-z11, some 32 billion light years away, was Hubble’s most distant discovery, but the picture was faint.
According to Espinoza, the new telescope would supplement, rather than replacing, the work done by Hubble. He is a member of the James Webb team at the agency that oversees research conducted with those space instruments, a non-profit consortium of scientists headquartered in Baltimore that advises NASA.
Espinoza will be the primary scientist on programmes that will use the Webb telescope to study two planets in distant planetary systems. One of them, K2-141b, is about half the size of Earth, and the other, WASP-63b, is a gas giant close to Jupiter.
“Hubble can’t perform the kinds of observations we need to learn about the atmospheres of these planets, or other details, since it was designed before the first planets outside our solar system were detected,” Espinoza said.
Many of the proposed tasks for the Webb telescope were planned and approved in the 1990s as the observatory was under initial development, said Klaus Pontoppidan, an astronomer and Webb project scientist at the institute.
“We’ve just added the final projects that will be included during the first year or 13 months,” Pontoppidan said.
The institute, which solicits suggestions for Hubble each year, will do so for Webb as well, he added, and each of the space telescopes attracts more than 1,000 such ideas each year.
It will take about three months for the Webb telescope to power up, stretch its giant mirror, and begin observations. Following that, scientists from universities all over the world scheduled more than 10,000 hours of experiments for it.
Hundreds of hours
It takes an average of 25 hours to observe a single planet, but longer observations — such as detecting the oldest and farthest galaxies — will require about 200 to 300 hours, Pontoppidan said.
“The first galaxies in the universe, those are really faint objects, so you have to stare at them for a long time,” he said.
Another big astronomy question for the telescope is to determine which came first — galaxies or the black holes that reside at the heart of most large galaxies, said Rogier Windhorst, an astronomer and physics professor at Arizona State University.
While he’s been waiting for the launch of Webb, Windhorst and his colleagues have conducted simulations that attempt to envision what the telescope can achieve, but those simulations cannot fully anticipate such discoveries, he said.
“It’s going to be like Galileo first looking at the sky on a telescope, you know, discovering the moons around Jupiter in the rings of Saturn,” Windhorst said. “Our eyes are going to be reopened to the universe. … So, we’re going to see new and unexpected things that we’ve never dreamed of.”
Thousands on project
Thousands of people have worked on building the Webb telescope at NASA contractor Northrop Grumman’s facility in Redondo Beach, Calif., said Bill Ochs, project manager for the space agency.
That number is starting to dwindle, he said, as NASA just completed the final test of the mirror unfolding devices last week. The spacecraft must fold for launch because it is too large to fit inside any existing rocket’s nose cone.
“The astronomy community at large has developed the goals for James Webb over the years, especially the goal to understand the formations of the first galaxies and planets,” Ochs said.
“Looking at other Earth-like planets is something that came about later in its development, and I think that science will be exciting — especially if we find an atmosphere that could support life.”