Skip to Content
Uncategorized

Lost Rover Found on Moon With Retroreflector Still Intact

The Russian Lunokhod-1 rover, lost for over 30 years, is surprisingly well-preserved, say astronomers who have worked out its position to within a few centimetres

On 17 November 1970, the Soviet Union’s Luna 17 mission touched down on the surface of the Moon. The lander carried a huge rover the size of a small car, called Lunokhod-1, which trundled off into lunar landscape. Over the next year or so, Lunokhod-1 travelled some 10 km over the lunar surface, sending back tens of thousands of images and carrying out soil analyses at over 500 sites.

Even after it stopped working, Soviet and French scientists continued to bounce laser light off an array of French-built mirrors on the rover’s back. However, the last recorded glimpse of the rover was in May 1974 and the exact details of its position have since been lost.

That’s been a constant source of irritation for Tom Murphy at the University of California, San Diego, and pals who regularly bounce laser light off the other known reflectors on the lunar surface left by Apollos 11, 14 and 15 and Lunokhod-2.

More reflectors allow them to more accurately measure the position of the Moon. Getting the reflectors up there is not easy, so to have lost one is particularly galling.

The situation changed in March this year when a team analysing images from NASA’s Lunar Reconnaissance Orbiter spotted the Luna 17 landing site and the rover’s tracks. This pinpointed the rover’s position to within a few hundred meters.

On 22 April, Murphy and his crew fired their laser in that direction and immediately detected a return. Not only was Lunokhod-1’s retroreflector still working, but it turns out to be in significantly better condition that its sister craft’s. “The initial return was surprisingly bright, far surpassing the best-ever return signal from the twin reflector on Lunokhod 2,” say the team.

That’s good news. The rediscovery of the reflector could have an important impact in several areas of science that depend on accurately measuring the position and orbit of the Moon. Laser rangefinding currently provides the most precise tests of many aspects of gravity, including the strong equivalence principle, the constancy of Newton’s constant, geodetic precession, gravitomagnetism and the inverse square law.

“Ranging to this reflector will significantly advance the precision of Lunar laser rangefinding and the resulting gravitational and lunar science,” say Murphy and the team.

Nice to see a happy ending. Like being reunited with a long lost friend.

Ref: arxiv.org/abs/1009.5720: Laser Ranging to the Lost Lunokhod 1 Reflector

Deep Dive

Uncategorized

Embracing CX in the metaverse

More than just meeting customers where they are, the metaverse offers opportunities to transform customer experience.

Identity protection is key to metaverse innovation

As immersive experiences in the metaverse become more sophisticated, so does the threat landscape.

The modern enterprise imaging and data value chain

For both patients and providers, intelligent, interoperable, and open workflow solutions will make all the difference.

Scientists have created synthetic mouse embryos with developed brains

The stem-cell-derived embryos could shed new light on the earliest stages of human pregnancy.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.