NASA maps out giant solar eruption as it swept past Earth's orbit

Wednesday, September 24, 2014, 12:58 PM - In July 2012, NASA satellites observed three solar eruptions blasting out in quick succession, producing an immense wave of solar matter that, had it impacted on Earth's magnetic field, may have disrupted satellites and caused widespread blackouts here on the surface that could have lasted for months. A new study, using data from those satellites and from Earth-based observatories, is giving us the clearest look so far at the enormity of this event.

The fleet of Sun-watching satellites that NASA and the European Space Agency have in space - the STEREO 'twins' and SOHO - have been out in space for years, each keeping a constant vigilant eye on the Sun's activity. They not only gather information for scientific study, granting us new insights into the 'monster nuclear furnace' at the centre of our solar system, but they also watch for sunspots, solar flares and coronal mass ejections. Coronal mass ejections, or CMEs, are of particular interest, and even concern, to scientists, because of their potential effects here on Earth. Our planet's magnetic field protects us from most of the direct impacts as the billions of tons of solar plasma contained in each CME sweeps past us. Smaller CMEs can generate increased aurora activity, like we saw a couple of weeks ago, but larger ones can cause intense geomagnetic storms, which can damage the electronics of orbiting satellites and generate strong currents in electrical lines here on Earth that can take down entire power grids.

RELATED: Powerful solar storm narrowly missed Earth in 2012

As the video above shows, satellites and observatories here on Earth watched as three coronal mass ejections erupted from the Sun's surface in July 2012 - one on July 19 and then two more nearly on top of one another on July 23. Each was only considered to be a 'moderate' blast, but their combined effects were quite dramatic. As the first of these three plasma waves spread out from the Sun, it swept up the particles from the solar wind (which tend to slow CMEs down), leaving behind a relatively clear region of space in its wake. This clear spot is what the following two CMEs erupted into. Combined together into one massive wave-front, they were able to travel along at incredible speeds - between 10 and 12 million kilometres per hour. According to NASA, in the nearly eight years that their STEREO satellites have been operating, this was the fastest CME the satellites had ever seen.

Given its combination of size and speed, this event was quite the eye-opener for scientists here on Earth. Although they scrutinize any Earth-directed CME for potential problems, seeing this kind of effect from three moderate-level eruptions was a first. Based on the data they collected, if that massive CME had been aimed right at us, it could have rivaled or even exceeded the impact of the Carrington CME of 1859. While there were only a few telegraph lines in operation to be affected back in the mid-1800s, the impact on our current technologies would be far, far worse. According to what Prof. Daniel Baker, of the University of Colorado's Laboratory for Atmospheric and Space Physics, told NASA, we would likely still be "picking up the pieces" today.

This new study wasn't just an exercise in raising our 'threat level' about CMEs. According to NASA, the model they produced of the event will help scientists better understand how CMEs happen (since not all solar flares produce them), and it will provide a better way to examine Earth-directed CMEs in the future.

CLICK BELOW TO WATCH: How do you tell the difference between a solar flare and a CME? While one can take days to reach us, the other impacts in just minutes!