Mirror diameter6.5 m
325Acorn lengths
2 hundredthsAircraft carrier lengths
Photo from Wikimedia Commons
James Webb Space Telescope Primary Mirror
A golden honeycomb peering into the origins of the universe/Engineering Marvels
The JWST's primary mirror is 6.5 meters across, made of 18 hexagonal beryllium segments coated with a microscopic layer of gold. Each segment can be individually adjusted to within 10 nanometers. The total mass of gold used is only about 48 grams, roughly enough to make two wedding rings. The mirror had to fold origami-style to fit inside its rocket.
Measurements
Collecting area25.4 m^2
2,822Phone screens
9.1 tenthsStudio apartments
9.7 hundredthsTennis court areas
Mirror mass705 kg
2.4 octillionGlucose molecule weights
181Gallons of milk
70.5 sextillionRhinovirus particles
Gold coating total mass4.8 hundredths kg
48 quadrillionVirus weights
425 millionthsManhole covers
4,000Housefly weights
About 48 grams
Gold coating thickness100 billionths m
5.5 billionthsBowling lane lengths
16.7 billionthsIce cream truck lengths
5.6 quintillionthsLight-minutes
100 nanometers
Segment alignment precision10 billionths m
6.6 billionthsDesk widths
1.4 billionthsSoccer goal widths
10 nanometers