Story by Chris Knight • National Post
An artist's conception of a solar storm that hit Earth in 1989, knocking out Quebec's power grid.© Provided by National Post
This week it was reported that a solar storm had struck the Earth a day ahead of schedule , for unknown reasons. Some speculated that the coronal mass ejection (CME) that was the cause of the storm was moving faster than expected. Others suggested it was an entirely different CME that had escaped our notice. Here’s what to know about solar storms.
What is a solar storm?
A solar storm is a disturbance on the surface of the sun, usually in the form of a large explosion called a solar flare, or a burst of plasma known as a coronal mass ejection, or CME. When the charged particles from the storm reach the Earth they interfere with our planet’s magnetic field in what’s known as a geomagnetic storm.
Are they dangerous?
Solar storms pose no direct risk to humans, as long as they’re shielded by the Earth’s atmosphere. So if you’re not in space, you’re fine. In fact, they make for great viewing of the Northern Lights, as the Earth’s auroral displays become brighter and are visible farther south than usual.
However, they can pose great risks to electrical and electronic equipment. On March 13, 1989, Hydro-Quebec experienced a complete blackout of its system due to a powerful solar storm. The solar particles couldn’t easily pass through the Canadian Shield and instead found an outlet through transmission lines. The province subsequently invested billions of dollars in toughening up its systems against future storms.
Even more powerful was the Carrington Event, a solar storm that hit the Earth in 1859 and remains the strongest one recorded to date. Telegraph operators reported sparking and even small fires in their equipment, while some disconnected their power sources and were still able to receive and transmit messages just by using the current passing through the atmosphere.
A solar storm in February of 2022 caused 40 SpaceX Starlink satellites to fail and fall back to Earth during launch, not because their electronics were fried, but because the storm caused Earth’s outer atmosphere to heat up and expand slightly, meaning the small satellites didn’t have enough fuel to reach orbit.
That said, it should be noted that solar storms tend to affect large-scale infrastructure such as power lines, and not individual devices like a cellphone, computer or car. In a recent interview with Scientific American , heliophysicist Erika Palmerio advised caution, not panic.
“As a person who works with this every day, I am way more scared of a ‘doomsday’ derived from terrestrial weather like forest fires, hurricanes and extreme weather,” she said. “We have to monitor, and we have to be prepared. But we do not have to lose sleep over this.”
A sunset on Mars. NASA’s rovers on the Red Planet have been used to observe parts of the sun not visible from Earth.© NASA
Can we predict solar storms?
Much like terrestrial weather, solar storms are unpredictable. But, like the weather, we can make forecasts and educated guesses. Solar flares and storms tend to reach their peak roughly every 11 years, as the sun goes through what’s known as a solar cycle. Solar cycle 1 started in 1755. We’re near the peak of solar cycle 25 now, expected to reach its maximum sometime between now and 2025. So the next few years are likely to see more and stronger solar storms.
It’s also worth noting that solar flares release energy at the speed of light, so there’s no advance warning for the eight minutes it takes their energy to reach us from the sun. Coronal mass ejections can take several days to reach Earth, so some warning is available.
Spacecraft like the Solar Terrestrial Relations Observatory (launched in 2006) and the Parker Solar Probe (launched in 2018) are studying the sun and its corona to help scientists better understand their behaviour.
We’re also getting assistance from other planets. Currently, Mars is on the opposite side of the sun from the Earth, and so scientists have asked the Perseverance rover there to periodically take a peek at the sun and report back on any sunspot activity not visible from Earth. The Curiosity rover performed a similar task in 2015, near the previous solar maximum, although its cameras were not as sensitive.
No comments:
Post a Comment