Flaming space debris re-entering atmosphere lights up California skies

A mesmerizing display of streaked lights in the night sky over Northern California on Friday was caused by the re-entry of flaming space debris into Earth’s atmosphere, experts have said.

Specifically, flaming pieces of communications equipment, which were jettisoned from the International Space Station in February 2020, streaked across the sky at 17,000 miles per hour, said Jonathan McDowell, an astrophysicist at the Smithsonian and Harvard Center for Astrophysics.

The equipment’s orbit had shrunk over the past two years until it was low enough to break apart and burn up.

“What you’re seeing are actually very small objects releasing a lot of energy, very high up, traveling extremely fast,” he said.

The retired 700-pound communications antenna, called the Inter-Orbit Communication System-Exposed Facility, went into space on a shuttle flight in 2009. About 10% of equipment like this could fall on Earth into small pieces, rather than melting along the way, Dr. McDowell said.

The equipment fell during an uncontrolled re-entry, meaning experts cannot predict exactly where the objects will land. Dr McDowell said pieces likely landed somewhere around Yosemite National Park. In contrast, the destination of equipment in controlled deorbit can be specified using rocket engines, he said.

Equipment the size of the one that created Friday night’s light show reenters Earth’s atmosphere every few weeks and has done so for 50 years, he said.

“They don’t happen very often in any given location, so it’s always new to people who see it,” Dr McDowell said. “For me, it’s just another Tuesday.”

On Instagram, King Cong Brewing Company in Sacramento posted a video of the streaking lights, adding, “It flew over the brewery tonight. What do you think? #UFO.”

Debris falling at night with clear skies can create a captivating light display for observers, said Moriba Jah, associate professor of aerospace engineering and engineering mechanics at the University of Texas at Austin.

But as the equipment burns, it can pollute the upper layers of the atmosphere, he said. Upon reaching the Earth’s surface, the equipment can also contaminate the oceans and land – and even injure people, although this scenario rarely occurs.

Privateer, a company co-founded by Dr. Jah, tracks around 48,000 man-made objects, ranging from a cellphone to the International Space Station itself. But only about 10% of them are functional, he said.

The rest is garbage.

“Humanity isn’t slowing down launching things into space,” he said. “I remember a busy year was one launch per month, and on average right now we’re launching over 12 satellites every week.”