NASA’s James Webb Space Telescope, a revolutionary US$9 billion instrument able to peer more deeply into the cosmos than ever, was launched from the European Space Agency’s launch base in French Guiana yesterday, opening a highly anticipated new era of astronomical exploration.
The powerful infrared telescope, hailed by NASA as the premier space-science observatory of the next decade, was released from a French-built Ariane 5 rocket after a 26-minute ride into space.
The James Webb is to take a month to coast to its destination in solar orbit about 1.6 million kilometers from Earth — about four times farther away than the moon. The telescope’s special orbital path is to keep it in constant alignment with Earth as the planet and telescope circle the sun in tandem.
By comparison, the James Webb’s 30-year-old predecessor, the Hubble Space Telescope, orbits Earth itself from about 600km away, passing in and out of the planet’s shadow every 90 minutes.
Named for the man who oversaw NASA through most of its formative decade of the 1960s, the new telescope is about 100 times more sensitive than Hubble, and is expected to profoundly transform scientists’ understanding of the universe and our place in it.
It is to mainly view the cosmos in the infrared spectrum, allowing it to peer through clouds of gas and dust where stars are being born, while Hubble has operated primarily at optical and ultraviolet wavelengths.
The new telescope’s primary mirror — consisting of 18 hexagonal segments of gold-coated beryllium — has a much bigger light-collecting area, enabling it to observe objects at greater distances, thus farther back into time, than Hubble or any other telescope.
Astronomers say that would bring into view a glimpse of the cosmos never seen before — dating to just 100 million years after the Big Bang, the theoretical flashpoint that set in motion the expansion of the observable universe an estimated 13.8 billion years ago.
Hubble’s view reached back to about 400 million years after the Big Bang, revealing objects that Webb would be able to re-examine with far greater clarity.
Aside from examining the formation of the earliest stars in the universe, astronomers are eager to study supermassive black holes believed to occupy the centers of distant galaxies.
The new telescope’s instruments also make it ideal to search for evidence of potentially life-supporting atmospheres around scores of newly documented exoplanets — celestial bodies orbiting distant stars — and to observe worlds much closer to home, such as Mars and Saturn’s icy moon Titan.
