Solar eruptions are sending a stream of particles towards Earth, creating spectacular auroras in both hemispheres.
The aurora borealis – in the northern hemisphere – will be potentially visible on Monday night in the US as far south as the midwest. The northern lights, more commonly seen within the Arctic Circle, could also be visible in Scotland.
In the southern hemisphere, the aurora australis could be visible in southern Australia, from Victoria to Western Australia.
The shimmering spectacle comes on the same night as a penumbral lunar eclipse, which will be visible around the world.
Australia’s Bureau of Meteorology’s space weather forecasting centre issued an aurora alert on Monday morning, saying a severe solar storm was in progress and the southern lights could be visible.
The storms are caused by coronal mass ejections, when clouds of plasma erupt from the sun’s outer atmosphere. Particles stream towards Earth, creating the spectacular display as they strike the Earth’s magnetic field.
In Australia, the storm peaked at 6 on the Kaus Index, a scale of one to eight measuring geomagnetic activity, meaning auroras will potentially be visible across Tasmania, along Victoria’s coastline and even on Western Australia’s south-west coast.
Both types of aurora are more commonly seen near the magnetic poles, in northern Canada and off the coast of Antarctica. Magnetic poles drift, and are not the same as the geographic poles.
The more severe the storm, the further away from the poles the auroras appear.
Severe storms can disrupt power networks and the satellites that provide navigation, surveillance and communication services. They can also pose a radiation risk to astronauts and people in high-flying aircraft.
A BoM spokesperson said significant space weather had “the potential to impact technology and critical infrastructure assets on Earth and in the near-Earth space environment”.
The BoM advises people hoping to see the aurora australis to find somewhere dark, like a beach or a hill with an unobstructed view south. Dark, moonless, cloudless skies away from city lights are ideal, and the best viewing time is between 10pm and 2am.
Last year, there were reports of shimmering night skies from Busselton in WA, to Ballarat and Canberra.
Macquarie University astronomer Dr Stuart Ryder said the 11-year solar cycle was likely nearing its peak this year.
“It goes from a relatively benign, calm state with very few sunspots on the surface to a very active phase about five or six years later, with a maximum number of sun spots,” he said.
“It’s much more likely to release huge flares of energy, enormous quantities of charged particles radiating away from the sun … their characteristic colours are green or red but people report blues, yellows, even purples.
“The more powerful the flare and the more it puts out, the greater the chance that people who live more towards the equator might get to see them.”
The BoM spokesperson said the current cycle began in 2019.
“The original prediction … was that solar maximum for this cycle would be reached in 2025, however, recent consensus amongst space weather researchers is that this cycle is likely to peak earlier, potentially in 2024,” the spokesperson said.
“This implies a higher level of solar activity over the next few years, but significant space weather can occur at other times in the cycle too.”
Meanwhile, at about 7pm tonight in Sydney and 7.30pm in Melbourne, the Earth’s shadow, or penumbra, will dim the moon.
The eclipse will be visible in spots including parts of Europe, North and South America, as well as parts of Asia and Africa. The details for people hoping to catch it are published on timeanddate.com.
Ryder said the eclipse will be half over by the time the moon clears the horizon. “Even when it does, the moon won’t pass through the deepest part of the Earth’s shadow,” he said. “It will be a full moon, and the upper part could appear a bit darker, because it’s deeper into the Earth’s shadow.
“Then the moon will move out of the shadow that it’s in and will be restored to full brightness … which unfortunately could ruin people’s chances of seeing the aurora.”
