Issued on: 11/07/2022 – 03:10 Modified: 11/07/2022 – 03:09
Washington (AFP) – The most powerful space telescope ever built, the James Webb, is poised to deliver its first full-color scientific images to the world on Tuesday.
Here’s an overview of this feat of human ingenuity in five key figures.
More than 21 feet
The centerpiece of the observatory is its huge main mirror, more than 21 feet (6.5 meters) in diameter and made up of 18 smaller hexagonal-shaped mirrors.
The observatory also has four scientific instruments: cameras to take pictures of space and spectrographs that break down light to study what elements and molecules make up objects.
The mirror and instruments are protected from our Sun’s light by a tennis court-sized thermal shield made up of five overlapping layers.
Each layer is thin, and together they ensure that the telescope operates in the darkness necessary to catch faint glimpses from the far reaches of the universe.
Millions of miles away
Unlike the Hubble telescope, which orbits the Earth, the Webb orbits the Sun, almost a million miles (1.6 million kilometers) away, or four times the distance from our planet to the Moon.
The spacecraft took almost a month to reach this region, called Lagrange Point two, where it remains in a fixed position behind the Earth and the Sun to give it a clear view of space.
Here, gravity from the sun and Earth balances the satellite’s centrifugal motion, meaning it needs minimal fuel for course correction.
13.8 billion years
In astronomy, the further you see, the further back in time you look.
Webb’s infrared capabilities are what make it uniquely powerful—allowing it to detect light from the earliest stars that has been stretched into infrared wavelengths as the universe expands.
This allows it to peer further back in time than any previous telescope, up to several hundred million years after the Big Bang, 13.8 billion years ago.
Three decades of waiting
The project was first conceived in the 1990s, but construction did not begin until 2004.
Webb’s launch date was then repeatedly pushed back. Originally scheduled for 2007, it finally took place on December 25, 2021 aboard an Ariane 5 rocket from French Guiana.
10 billion dollars
Webb is an international collaboration between the US space agency NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA), involving more than 10,000 people.
NASA’s lifetime costs alone will be roughly $9.7 billion, according to a Planetary Society analysis, or $10.8 billion adjusted for inflation to 2020 dollars.
© 2022 AFP
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