Startup tests fake sunlight at night and critics push back

Locals near Lone Pine, California, recently saw blinding light shining from the mountains at night. It was a demonstration by Reflect Orbital, a US startup that wants to put 50,000 mirror satellites in space within the next decade. The mirrors would bounce sunlight down to Earth after dark. The test drew complaints from some scientists, environmental groups and residents.

What the company wants

Reflect Orbital says its mirrors could light up places at night on demand, using an app. Planned uses include helping search-and-rescue teams, lighting crops, replacing broken streetlights and providing solar power for military operations. The company also says that shining sunlight on solar panels at night would cut reliance on fossil fuels.

What the test showed

The demonstration took place earlier this month near Mount Whitney in the Sierra Nevada. It did not use space mirrors. The company set up large mobile lights and compared the glow to a full moon. It worked with a local search-and-rescue team and called the test a realistic simulation. One local described the light as "blinding."

The real satellite

In July, the Federal Communications Commission (FCC) approved a first demonstration satellite, due to launch next year. It would orbit about 400 miles up. Its 59-foot mirror would send down beams 3 miles wide. The strength could range from moonlight to the brightness of the sun at noon.

Why critics object

A group of environmentalists and astronomers says the plan is a risk to the normal split between day and night. In August, four groups represented by Earthjustice asked the FCC to reconsider its approval. Their concerns include:

• Wildlife. Birds, insects and mammals rely on the day and night cycle to feed, shelter and mate.
• Sleep. Scrambled night and day could disrupt human body clocks.
• Eyes. Looking straight at the glare could cause harm, much like watching a solar eclipse.
• Stars. Astronomers say more glare and more satellites would make the sky harder to see.

Jan Hasselman of Earthjustice called it "an idiotic project" and said the 50,000-satellite plan "would really end the night sky as we know it." Climate scientist David Ho of the University of Hawaii warned against adding to the sun's energy reaching Earth, since global warming comes from an energy imbalance caused by greenhouse gases.

What happens next

Reflect Orbital says it has held "substantive discussions" with scientists and astronomers. It says it wants to avoid astronomical sites, national parks and wildlife-rich areas. The material does not say whether the FCC will reconsider its approval. It also does not say how the demonstration satellite will perform once it launches next year.