When was the James Webb Space Telescope launched?

April 24, 1990 December 25, 2021 January 1, 2020 October 31, 2018

Where does the James Webb Space Telescope orbit?

In low Earth orbit, like the Hubble Space Telescope On the surface of the Moon At the Sun-Earth L2 Lagrange point, about 1.5 million km from Earth — too far for astronauts to service In orbit around Mars

How large is the James Webb Space Telescope's primary mirror?

2.4 meters — the same size as Hubble 6.5 meters in diameter, made of 18 hexagonal gold-coated beryllium segments 10 meters — larger than any ground telescope 30 meters — the same as the planned Extremely Large Telescope

What type of light does Webb primarily observe?

X-rays, to study black holes in unprecedented detail Visible light, for sharper images than Hubble Radio waves, to detect the first signals from early galaxies Infrared light, from near-infrared to mid-infrared wavelengths

Why does Webb need to observe in infrared to see the first galaxies that formed after the Big Bang?

Ancient galaxies only produce infrared light because they are cooler than modern galaxies The universe's expansion has stretched the light from those distant galaxies from visible wavelengths into infrared — a process called cosmological redshift Infrared light travels faster than visible light and therefore shows us older events Early galaxies are surrounded by so much dust that only infrared can penetrate it

What is the purpose of Webb's sunshield?

To protect Webb from micrometeorite impacts To generate solar power for Webb's instruments To block heat from the Sun, Earth, and Moon so Webb's infrared detectors can be kept extremely cold and sensitive To shield Webb's communications antenna from solar interference

How far back in cosmic history can Webb see?

Webb can only see galaxies that formed after the Milky Way Webb can observe galaxies that formed just 100 to 400 million years after the Big Bang — within the first few percent of the universe's 13.8-billion-year history Webb can see all the way back to the Big Bang itself Webb can only see objects within our own Milky Way galaxy

What groundbreaking atmospheric detection did Webb make for the first time in exoplanet science?

Webb discovered oxygen in an exoplanet atmosphere — a potential sign of life Webb detected carbon dioxide (CO2) in the atmosphere of an exoplanet (WASP-96b) for the first time Webb found liquid water clouds on an exoplanet for the first time Webb measured the exact temperature of an exoplanet's surface for the first time

Which objects within our own solar system has Webb already imaged with new detail?

The surface of Mars and the volcanoes of Io The hidden oceans of Europa and Enceladus Neptune's rings and Jupiter's auroras, among other solar system targets The dark side of Mercury and the polar ice caps of Pluto

Why was it such a technological challenge to build and launch the James Webb Space Telescope?

It was not particularly difficult — Webb used existing Hubble technology The main challenge was getting funding, not the engineering Its 6.5m mirror and tennis-court sunshield had to fold up to fit in a rocket, then unfold perfectly in space — with over 300 single points of failure during deployment The biggest challenge was training astronauts to assemble it in orbit

Why is gold used as the coating on Webb's mirror segments?

Gold is resistant to damage from cosmic rays Gold is the least massive metal available, saving launch weight Gold reflects infrared light extremely efficiently — much better than aluminum or silver Gold prevents the mirror from cracking in the extreme cold of space