A 5,000-pound satellite is expected to fall to Earth this week

(CNN) — A European Space Agency satellite is expected to reenter and largely burn up in Earth’s atmosphere on Wednesday morning.

The agency’s Space Debris Office, along with an international surveillance network, is monitoring and tracking the Earth-observing ERS-2 satellite, which is predicted to make its reentry at 11:32 a.m. ET Wednesday, with about a 4.5-hour window of uncertainty. The ESA is also providing live updates on its website.

“As the spacecraft’s reentry is ‘natural’, without the possibility to perform manoeuvers, it is impossible to know exactly where and when it will reenter the atmosphere and begin to burn up,” according to a statement from the agency.

The exact time of the satellite’s reentry remains unclear due to the unpredictability of solar activity, which can change the density of Earth’s atmosphere and how the atmosphere tugs on the satellite. As the sun nears its 11-year cycle’s peak, known as solar maximum, solar activity has been ramping up. Solar maximum is expected to occur later this year.

The sun’s increased activity already had an impact on speeding up the reentry of the ESA’s Aeolus satellite in July 2023.

The ERS-2 satellite has an estimated mass of 5,057 pounds (2,294 kilograms) after depleting its fuel, making it similar in size to other space debris that reenters Earth’s atmosphere every week or so, according to the agency.

At around 50 miles (80 kilometers) above Earth’s surface, the satellite is expected to break apart and the majority of the fragments will burn up in the atmosphere. The agency said that some fragments could reach the planet’s surface, but they won’t contain any harmful substances and will most likely fall into the ocean.

ERS-2’s backstory

The Earth-observing ERS-2 satellite first launched on April 21, 1995, and it was the most sophisticated satellite of its kind at the time to be developed and launched by Europe.

Along with its twin, ERS-1, the satellite collected valuable data on the planet’s polar caps, oceans and land surfaces and observed disasters like flooding and earthquakes in remote areas. The data gathered by ERS-2 is still used today, according to the agency.

In 2011, the agency decided to end the satellite’s operations and deorbit it, rather than adding to the swirl of space junk orbiting the planet.

The satellite executed 66 deorbiting maneuvers in July and August of 2011 before the mission officially concluded later that year on September 11. The maneuvers burned through the rest of the satellite’s fuel and decreased its altitude, setting ERS-2’s orbit on a trajectory to slowly spiral closer to Earth and reenter the atmosphere within 15 years.

The chances of an individual person being injured by space debris each year are less than 1 in 100 billion, about 1.5 million times lower than the risk of being killed in an accident at home, according to the agency.