One Apollo 11 Experiment Is Still Going 50 Years Later

The Lunar Laser Ranging Experiment lets NASA precisely measure the distance between Earth and the moon

5 min read
Image of the laser deployed from the facility and pointing toward the sky.
Goddard’s Laser Ranging Facility in Greenbelt, Md., directing a laser (green beam) toward the Lunar Reconnaissance Orbiter spacecraft in orbit around the moon (white disk). The moon has been deliberately over-exposed to show the laser.
Photo: Tom Zagwodzki/Goddard Space Flight Center

THE INSTITUTEIf nothing else will convince someone that humans once walked on the moon, NASA’s lunar ranging experiment (LURE) should. It’s because of that experiment that scientists know the precise distance between the Earth and the moon with centimeter accuracy.

The LURE’s first demonstration began on 1 August 1969, when a pulse of trillions of photons was shot out of a telescope at Lick Observatory on Mount Hamilton, outside of San Jose, Calif. The laser pulse traveled to the moon and returned after reflecting off a 1-meter-wide array of mirrors—retroreflectors—that Apollo 11 astronauts had placed on the lunar surface 12 days earlier.

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Tony Fadell: The Nest Thermostat Disrupted My Life

The Nest founder tells of years in pursuit of a thermostat he actually likes

7 min read
A man holds a circular device in front of a blue wall that says nest on it.

Tony Fadell shows off the Nest thermostat in 2012.

Karsten Lemm/picture-alliance/dpa/AP

The thermostat chased me for 10 years.

That is pretty extreme, by the way. If you’ve got an idea for a business or a new product, you usually don’t have to wait a decade to make sure it’s worth doing.

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