After 53 years in space, Kosmos 482 entered the Earth's atmosphere at Moscow time 09:24, writes Roskosmos on Telegram. Then it fell down into the "Indian Ocean west of Jakarta".
The EU's office for space surveillance confirms that the spacecraft made an "uncontrolled return" towards the Earth, writes AP.
It is not clear how much of the 500 kilo heavy spacecraft survived the orbit.
The risk of someone being hit by the space debris was extremely low, researchers believe.
Kosmos 482, which was launched in 1972, was supposed to land on Venus in the 1970s. Instead, it got stuck in orbit around the Earth.
Considering how large a part of the Earth consists of water, it has always been likely that it would land in the sea. But activity from the sun and the spacecraft's deteriorated condition after such a long time in space have contributed to the uncertainty about where it would crash.
