Massive satellite falling through Earth's atmosphere Wednesday: What to know

(NEXSTAR) — A massive satellite is set to reenter Earth's atmosphere Wednesday, according to the European Space Agency.

The ESA's European Remote Sensing 2 (ERS-2) satellite launched in April 1995 and "collected a wealth of valuable data on Earth's land surfaces, oceans, and polar caps," the agency explains. It also helped "to monitor natural disasters such as severe flooding or earthquakes in remote parts of the world."

While it was once the most sophisticated Earth-observer launched by Europe, ERS-2's operations ended in 2011. That year, the satellite underwent more than five dozen deorbiting maneuvers, burning off fuel and bringing it to an altitude that would keep it from colliding with other bits of space debris.

Since then, the ESA says all of the satellite's instruments and electronic systems have been deactivated, and the batteries discharged "to reduce the risk of ERS-2 fragmenting into smaller pieces while passing through important regions during its orbital decay."

ERS-2 is now set to move through Earth's atmosphere as of Wednesday. While it is expected to burn up in our atmosphere, the ESA notes "it is impossible to predict exactly when and where the satellite will begin to burn up."

The agency also can't control the 5,050-pound satellite anymore; it can only track its progress. However, the ESA says an object of similar mass reenters our atmosphere "every week or two."

It is expected that ERS-2 will break apart roughly 50 miles above Earth's surface "and the vast majority of these [fragments] will burn up in the atmosphere."

It's difficult to say when exactly ERS-2 will move through our atmosphere, but in an update early Wednesday morning (around 6 a.m. ET), the ESA predicted the satellite would reenter around 10:40 a.m. ET, plus or minus about an hour and a half. Shortly before 11 a.m. ET, the ESA wrote on X that there was "nothing to report as of yet."

In another update, the ESA estimated reentry at closer to 12 p.m. ET, with uncertainty anywhere between 30 minutes.

As part of that update, the ESA also provided a possible "ground track" of where ERS-2 could begin to break up. The agency estimated Wednesday morning that that could happen in the atmosphere above the Pacific Ocean, off the coast of California. Shortly before 12 p.m. ET, those estimates change, putting reentry over the Norweigan Sea between Iceland and Norway.

"Some fragments could reach Earth’s surface, where they will most likely fall into the ocean," the ESA says. "None of these fragments will contain any toxic or radioactive substances."

It's worth noting that the Earth is surrounded by countless bits of space debris. You have a one-in-a-billion chance of being injured by any of it reentering our atmosphere — and a better chance of winning the Powerball jackpot.