Cosmic Eye Exam Shows Jaw-Dropping Accuracy of Webb Telescope's Optics

The scope's main mirror must hold its shape even down to temperatures near absolute zero.

Sep 3, 2011 5:00 AMNov 12, 2019 4:21 AM


Sign up for our email newsletter for the latest science news

THE MOMENT NASA engineer Ernie Wright examines 6 of the 18 segments of the James Webb Space Telescope’s primary mirror in preparation for a final round of testing at Marshall Space Flight Center in Huntsville, Alabama. A laser system called an interferometer measures how the mirrors warp as they cool from room temperature to –415 degrees Fahrenheit, slightly below their normal operating range in space. The mirrors must hold their shape to within 25 billionths of a meter to perform properly.

THE SHOT Photographer David Higginbotham set remote flashes in front of himself and Wright to light the chamber. He held his Nikon D3 a bit above his eyes so the camera would not appear in the mirrors. The texture seen in the mirrors is the magnified reflection of a seam on Higginbotham’s clean-room suit.

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.