【Sisters Slave】

Before a Soviet-era spacecraft intended for Venuscrashed back to Earth over the weekend,Sisters Slave German astronomers watched it tumble through space. 

As Kosmos 482took its last laps, a German radar station spotted the uncrewed landing capsule passing over its antenna. The station, the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, has combined its observations with an image of a similar capsule to show the spacecraft's orientation and features in the radar reflection. 

The data, presented as a GIF farther down in this story, helped the European Space Agency track the probein its final hours, though its final resting place — most likely a watery grave — is still unknown. 

If it indeed plunged into the Indian Ocean as some computer simulations have suggested, "only the whales and albatross saw it," said Dutch scientist Marco Langbroek in a poston X.

The Venera mission, which launched from Kazakhstan on March 31, 1972, failed long before the Soviet Union could attempt to touch down on Venus. Because of a propulsion problem, it never escaped Earth's orbit. A half-century later, the landing capsule was predicted to reenterthe atmosphere. That day arrived on Saturday, May 10.

Space debris and expired satellites often fall back to Earth inconsequentially, mostly burning up on the way down. Whatever survives often plummets into an ocean, never to be found. 

This anticipated-yet-uncontrolled reentry was to be exceptional, though: It grabbed the attention of researchers and military officials because of its potential to survive the journey mostly intact. After all, the 1,000-pound spacecraft was built to withstand the harsh environment of an alien planet — the hottest in the solar system, in fact. Venus' climatecould melt lead, and the atmospheric pressure is 75 times that of Earth.

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Watch the GIF of the tumbling Soviet spacecraft in the above X post. Credit: Fraunhofer FHR

Fraunhofer FHR was likely the last to see Kosmos 482. It passed about 62 miles overhead on May 10, at 8:04 a.m. CEST, according to the station.  When the object was not detected again one orbit later, at 9:32 a.m. CEST, researchers reasonably assumed the landing or splashdown occurred between those two times.

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A tracking and imaging radar like the one used by the German station is a way to observe space, but it's not a telescope. It uses radio waves instead of light to study objects, such as satellites, debris, and meteors. 

Exactly where and when this Cold War space race relic died is unclear, as it seems there were no eyewitnesses to the fall. The Russian Space Agency Roscosmossaid it plummeted over the Indian Ocean, west of Jakarta, Indonesia, at 9:24 a.m. Moscow time, according to a Telegram post, and NASAappears to be accepting of that data. Other reports, some based on earlier predictions, varied. 

The U.S. Space Command, which tracks reentering space objects, has not confirmed any reports or provided its own data on Kosmos 482. An information request from Mashable wasn't answered Tuesday.