An old Nasa satellite is expected to fall to Earth this week, but experts tracking the spacecraft say chances are low that it will pose any danger.

The defunct science satellite known as Rhessi will plummet through the atmosphere on Wednesday night, according to Nasa and the US Defence Department.

Nasa said on Tuesday that the re-entry location is not being disclosed, given lingering uncertainty over when and where it might go down.

Most of the 660-pound (300-kg) satellite should burn up upon return, but some parts are expected to survive.

The space agency said in a statement the risk of anyone on Earth being harmed by plunging satellite pieces is “low” — about one in 2,467.

Rhessi — short for the Reuven Ramaty High Energy Solar Spectroscopic Imager — rocketed into orbit in 2002 to study the sun.

Before being shut down in 2018 because of communication problems, the satellite observed solar flares as well as coronal mass ejections from the sun.

It captured images in high-energy X-rays and gamma rays, recording more than 100,000 solar events.