The solar fireworks at the weekend were recorded by several satellites, including Nasa’s new Solar Dynamics Observatory (SDO) which watched its shock wave rippling outwards.
NASA’s Solar Dynamics Observatory is a spacecraft that launched in February. SDO provides better-than-HD quality views of the Sun at a variety of wavelengths.
Astronomers from all over the world witnessed the huge flare above a giant sunspot the size of the Earth, which they linked to an even larger eruption across the surface of Sun. The explosion was aimed directly towards Earth, which then sent a “solar tsunami” racing 93 million miles across space, the New Scientist reported.
Images from the Solar Dynamics Observatory hint at a shock wave travelling from the flare into space. Experts said the wave of supercharged gas will likely reach the Earth on Tuesday, when it will buffet the natural magnetic shield protecting Earth.
Sky viewers might get to enjoy some spectacular Northern Lights, or aurorae. Aurorae normally are visible only at high latitudes. However, during a geomagnetic storm aurorae can light up the sky at lower latitudes.
Sky watchers in the northern U.S. and other countries should look toward the north on the evening of August 3rd/4th for rippling “curtains” of green and red light.
However, scientists have warned that a really big solar eruption could destroy satellites and wreck power and communications grids around the globe if it happened today.
“This eruption is directed right at us, and is expected to get here early in the day on August 4th,” said astronomer Leon Golub of the Harvard-Smithsonian Center for Astrophysics (CfA). “It’s the first major Earth-directed eruption in quite some time.”
Dr Lucie Green, of the Mullard Space Science Laboratory, Surrey, followed the flare-ups using Japan’s orbiting Hinode telescope. “What wonderful fireworks the Sun has been producing,” the UK solar expert said.
“This was a very rare event – not one, but two almost simultaneous eruptions from different locations on the sun were launched toward the Earth.
“These eruptions occur when immense magnetic structures in the solar atmosphere lose their stability and can no longer be held down by the Sun’s huge gravitational pull. Just like a coiled spring suddenly being released, they erupt into space.”
“It looks like the first eruption was so large that it changed the magnetic fields throughout half the Sun’s visible atmosphere and provided the right conditions for the second eruption,” she added.
“Both eruptions could be Earth-directed but may be travelling at different speeds. This means we have a very good chance of seeing major and prolonged effects, such as the northern lights at low latitudes.”
The Sun goes through a regular activity cycle about 11 years long on average. The last solar maximum occurred in 2001. Its latest minimum was particularly weak and long lasting. This eruption is one of the first signs that the Sun is waking up and heading toward another maximum. [Solar Dynamics Observatory via Daily Telegraph (UK) and New Scientist]