Nasa’s time-travel machine: five facts about the James Webb Space Telescope
World’s most powerful telescope expected to start operating in October
An enormous space telescope that will give astronomers a peek into the early universe is scheduled to launch in October.
The James Webb Space Telescope (JWST), the world’s most advanced space observatory, was in development for nearly two decades and is expected to create an astronomical revolution once operational.
The $10 billion "time machine" will help astronomers to study what the universe looked like millions of years ago.
It is much more advanced than the Hubble telescope because of its breakthrough technology, design and its planned location in space.
Hubble made countless discoveries after it was launched in 1990 and provided millions of images of planets, galaxies, nebulas and stars.
The new telescope is equipped with sensitive cameras and spectrographs that will capture light directed into them by JWST’s huge golden mirror.
It is being developed by Nasa with its partners, the European Space Agency and the Canadian Space Agency.
With the upcoming launch, The National looks at five facts that make the James Webb Space Telescope extra special.
1. It is ‘time travelling’ into the past
The telescope will show us what the universe was like 100 million to 250 million years after its birth. In the Big Bang theory, it is believed the universe came into existence 13.8 billion years ago.
JWST will detect stars and galaxies 13.6 billion light years away, capturing light sources in the early universe and studying the formation of galaxies.
The telescope will detect infrared light, allowing it to capture an object’s heat source.
The space observatory’s cameras are so sensitive, they can spot the heat signature of a bumblebee on the lunar surface.
2. Honeycomb mirrors
A telescope’s mirror helps reflect light into its cameras. The better the mirror, the more the observatory will capture.
JWST has 18 primary mirrors built together in the shape of a honeycomb. In total, it measures 6.5 metres in diameter.
The mirror is six times bigger in area than Hubble’s and will be 100 times more powerful.
To help reflect infrared light more efficiently, the mirror is covered with a thin coating of gold.
3. Unique orbit
JWST will be placed much further out in space and in a different orbit than the Hubble, allowing it to see greater distances.
Instead of an orbit around the Earth, the telescope will orbit the Sun. It will be in line with Earth, but 1.5 million kilometres from the planet and four times farther away than the Moon. This position in space is called a Lagrange point.
The mirror will be kept at a temperature of minus 233°C to shield it from the Sun. It has a five-layer sunshield that is the size of a tennis court and which weakens the heat from the host star by more than a million times.
4. Hunt for life
One of the main objectives of the telescope is to study the atmospheres of exoplanets – planets outside the Solar System.
This will help in its search for building blocks of life elsewhere in the universe.
Once operational, it will look for oxygen present in the atmospheres of planets in distant galaxies.
5. How it will launch into space
The school bus-sized telescope, which measures 21 metres by 14.6 metres, will have to fold up to fit into the launch rocket.
It was designed in a way to make this possible.
JWST will launch aboard the Ariane 5 rocket in October, near French Guiana in South America.
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Updated: April 7, 2021 12:55 PM