Cambridge astronomers help develop James Webb Space Telescope - the 'world's most magnificent time machine'
Kavli Institute for Cosmology involved in creating NIRSpec instrument for NASA's incredible $8.8billion telescope
Cambridge is playing its part with the creation of “the world’s most magnificent time machine”.
The James Webb Space Telescope will be NASA’s premier observatory for the next decade, taking over from the Hubble Space Telescope.
Bristling with innovative technology that will give astronomers new insights, the $8.8billion telescope is an international collaboration between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).
Its 21.3ft primary mirror is made of 18 segments of ultra-lightweight beryllium that will unfold and adjust to shape after launch. A tennis court-sized five-layer sunshield will reduce heat from the sun by a factor of more than a million.
It has four eyes – cameras and spectrometers – that will be able to record the faintest signals and give us insight into every phase in the history of the universe, from the first luminous glows after the Big Bang to the formation of solar systems such as our own.
One of these instruments is called NIRSpec – Near Infrared Spectrograph. With programmable microshutters, it will be sensitive to radiation from the most distant galaxies and capable of observing more than 100 objects simultaneously. Researchers at the Kavli Institute for Cosmology in Cambridge, including Dr Renske Smit, are heavily involved in NIRSpec.
Dr Smit, who specialises in early galaxies and stars, said: “With this telescope, we might be able to see the very first stars for the first time. To have this kind of privileged access to world-leading data is truly a dream come true.
“What we are doing is designing a really big survey to look at a lot of galaxies roughly at this epoch – samples that we’ve not been able to collect before.
“Cambridge is involved with NIRSpec because it’s the European Space Agency that built that instrument so it’s a European team of astronomers working on this survey.”
The telescope will help astronomers look at the composition of gas and use kinematics to look at the motion of celestial bodies.
“At the moment we’re looking at where we want to point the telescope, figure out the best targets to look at and try to see if we can write a good data reduction for it. It’s prep work for a really big research project,” added Dr Smit.
It is hoped the telescope – described recently by NASA official Mark Voyton as the “world’s most magnificent time machine” – will launch in late spring 2019.
It will shortly leave Houston, Texas, where elements of it have undergone testing.
“It’s the successor to Hubble and then some,” said Dr Smit. “They will try to keep Hubble working but they won’t do any service missions. Hubble is very good at taking images, and James Webb will also be, but we’ll be able to see further back in time. It may even take us back to 200 million years after the Big Bang, we hope.
“Just after the Big Bang there is a period called the Dark Ages, when there is no starlight, no galaxies and we don’t know how long that period is.”
Could we ever see the Big Bang?
“It’s theoretically possible but the most distant light is the radiation directly out of the Big Bang but it isn’t emitted until a few hundred thousand years afterwards. It’s called the cosmic microwave background radiation,” explained Dr Smit. “It used to be very energetic light but because it’s travelled so far it’s completely red-shifted to microwave wavelength.
“Seeing further back than that is very hard but in principle there could be something like background radiation of neutrinos from even further back in time.”
You don’t need the world’s most ambitious and expensive telescope to detect cosmic microwave background radiation, though.
“It is a radio wavelength so it’s actually quite easy to detect,” said Dr Smit. “When you used to have old televisions and you had the black and white effect because you weren’t tuned in, one part of the radiation you would receive was the Big Bang radiation. You can’t use that anymore with kids!”
Dr Smit is keen to inspire the next generation of star-gazers.
“I would like to contribute to changing the perception of what a science professor looks like,” she said.
“Women in the UK and worldwide are terribly underrepresented in science and engineering and as a result, people may feel women either don’t have the inclination or the talent to do science.
“I hope that one day I will teach students that don’t feel they represent the professor stereotype and make them believe in their own talent.”