Dead Satellite Spotted Falling Toward Earth

Sometime on Wednesday, a 5,000-pound satellite will come crashing down to Earth. The European Space Agency's European Remote Sensing 2 (ERS-2) satellite, which orbited Earth from 1995 to 2011, is expected to reenter Earth's atmosphere Wednesday, though exactly when is uncertain. As of Tuesday morning, the satellite was expected to fall at 3:53pm ET, plus or minus nearly eight hours. "As the spacecraft's reentry is 'natural', without the possibility to perform maneuvers, it is impossible to know exactly where and when it will reenter the atmosphere and begin to burn up," the ESA says, per CNN, which reports some of the uncertainty stems from "the unpredictability of solar activity, which can change the density of Earth's atmosphere and how the atmosphere tugs on the satellite."

The Earth observation satellite spent 16 years collecting data on Earth's oceans, land surfaces, and polar ice caps until the end of the mission in 2011. ERS-2 was then brought out of orbit, putting the satellite "on a trajectory to slowly spiral closer to Earth and reenter the atmosphere within 15 years," per CNN. Australian commercial imaging company HEO Robotics captured images of the satellite nearing Earth's atmosphere last week, per Space.com. Now roughly 50 miles above Earth's surface, ERS-2 has roughly the same mass as other space debris that burns up in Earth's atmosphere every few weeks, according to ESA. In other words, it's not a huge concern.

Most of the satellite is expected to burn up, though some fragments could reach Earth's surface. If they make it to land, you can take comfort in knowing "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," per CNN. "None of these fragments will contain any toxic or radioactive substances," the ESA says, per Space.com, adding that "deorbiting satellites at the end of their life and ensuring they reenter Earth's atmosphere is a fundamental tool in keeping our busy space highways clear from defunct, lingering satellites, preventing collisions in orbit, and mitigating the creation of further space debris." (More satellite stories.)