An old Nasa satellite is expected to fall to Earth this week after 16 years’ service. It is expected to re-enter the Earth’s atmosphere at approximately 9.30pm on Wednesday and there are concerns about falling debris.
On Monday, the space agency said: “NASA and the Defense Department will continue to monitor reentry and update predictions.”
Here’s what you need to know.
What is the Rhessi observatory?
Rhessi is short for the Reuven Ramaty High Energy Solar Spectroscopic Imager. Since 2002, the Rhessi observatory has been in orbit to take photos of the sun until its communications broke down in 2018. Before being shut down, it observed solar flares and coronal mass ejections from the sun, capturing images in high-energy X-rays and gamma rays.
Before the Rhessi observatory existed, no gamma ray or high-energy X-ray images of solar flares had been taken. It recorded more than 100,000 X-ray events, helping scientists study the energy particles in solar flares.
But this week the old Nasa satellite is expected to fall to Earth.
When will it hit Earth?
The defunct spacecraft is expect to plummet through the atmosphere, according to Nasa and the US defence department.
On Tuesday, Nasa said that the re-entry location is not being disclosed. Its final descent could even be visible as a fireball if the skies are very clear.
This will be the second retired Nasa satellite to crash into Earth this year after a 2,450kg one came down in January.
Will it be dangerous?
The majority of the 300kg satellite will burn up as it passes through the upper atmosphere, however, some parts are expected to fall to Earth. Experts said that the chance of debris from its descent hitting someone or posing any danger are low even though it’s unclear where debris might fall. The space agency said the risk of anyone on the surface being harmed by plunging satellite pieces is low – about one in 2,467.
