Webb telescope sees things that we can’t
In this year’s early winter months, the world watched in astonishment as the James E. Webb space telescope unfolded carefully in space and flew to its perch, a million miles away from Earth.
Now it’s time to exhale and begin to be astonished again, a hundred times over.
The Webb telescope is ready to begin working. The public will get its first look at its images at a news conference July 12.
The anticipation is great over how it will help Earthlings learn about things near and very far away.
“Everyone is so excited about the first images that will come from it,” said Diana Hannikainen, observing editor of Sky & Telescope Magazine.
“It will be like Hubble,” planetary astronomer Heidi Hammel said of the revolution wrought by the Hubble Space Telescope when it began sending focused observations to earth in 1994.
The Webb telescope — named after NASA administrator James E. Webb, who shepherded the Mercury, Gemini and Apollo missions in the 1960s — is the most complicated telescope ever assembled. It’s also the most expensive, costing about $10 billion.
It’s a joint project of NASA, the European Space Agency and the Canadian Space Agency. It took decades to plan and build before its launch on Dec. 25 — Christmas Day — in 2021.
Hammel is vice president for science of the Washington, D.C.-based AURA — the Association of Universities for Research in Astronomy. She lived in Ridgefield for many years before taking the AURA post in 2010.
She has been involved in the Webb mission for many years, both on its ad hoc planning groups and as a member of its scientific working group since 2003. She’s now leading the team that will decide what Webb will study in our own solar system.
In an orbit a million miles away from Earth, the Webb telescope and its sunshield are facing away from us, so it cannot look at Mercury, Venus the Earth or our moon. But outward, from Mars and beyond, it will see things never seen before.
The Webb telescope will not look at space objects in visible light, which Hubble does. Instead, it will work in the infrared spectrum — light that human eyes can’t discern.
Because of its position far away and because of the size and sensitivity of its mirrors, it will be able to see very deep into space, studying some of the first galaxies that formed after the Big Bang. It will greatly increase our understanding of how the universe began.
And it will do lots of other things, too.
“It will be able to look at the things all other telescopes look at,” said Hannikainen of Sky & Telescope Magazine. “It will look at clusters of galaxies, at young stars, at star clusters.”
The Webb may be valuable in studying exoplanets — the planets that orbit other stars, Hannikainen said.
Beginning with the first confirmed observation of an exoplanet in 1995, the discoveries of what’s out there have leaped forward thanks to space telescopes such as Kepler and TESS — the Transiting Exoplanet Survey Satellite. We now have identified more than 5,000 of these objects..
But because they are comparatively so small — even the giant ones — and far away, we know they exist only because of disruptions in a star’s brightness as the planet passes by. Hannikainen said the Webb telescope can use spectrographic analysis to study the atmospheres of exoplanets and greatly expand our knowledge about them.
AURA’s Hammel said her team will use the Webb telescope for a survey of our solar system from Mars out to the Kuiper Belt — the vast doughnut-shaped ring of millions of icy objects that circles the edge of our solar system.
Mars, for example, has been studied by mapping satellites, rovers and even a small zooming-around helicopter.
But all these instruments give us slices of information. The Webb telescope, Hammel said, can stand back and see Mars’ atmosphere as a whole, giving us a muchmore complete picture of the planet.
It will give us a greater understanding of Jupiter’s Great Red Spot, of Saturn’s rings and of the complex moons orbiting Jupiter and Saturn. It can look, in detail, at our neighborhood’s two ice giants — Uranus and Neptune. It will let astronomers study Kuiper Belt objects in a way they never have been able to do before.
“It will give us new eyes,’’ Hammel said. “Infrared eyes. But a whole new set of eyes.”
“Everyone is so excited about the first images that will come from it.”
Diana Hannikainen, observing editor of Sky & Telescope Magazine