Living with a star isn't easy. Sure, it gives you all the light, heat and energy a life-bearing planet needs, but sometimes it can lash out at you. Fortunately, this life-bearing planet has a pretty intelligent species on it that can detect when the sun is about to have a temper tantrum. And, we're getting better at it.
Today, at the Royal Astronomical Society's National Astronomy Meeting in Glasgow, Lucie Green presented data from Japan's Hinode spacecraft on magnetic "flux ropes" and their role in coronal mass ejections, or CMEs.
A CME is just what it sounds like: material thrown forth from the sun at very high speeds. If pointed at the Earth, it can disrupt radio communications, damage satellites, cause blackouts and make low-frequency radio astronomy a real pain. The more we know about and can predict these events, the better prepared we'll be.
The sun's activity is intimately tied to its magnetic field. As the sun is a differentially rotating ball of plasma, magnetic field lines can get twisted and turned and even broken. "Flux ropes" are bundles of magnetic field lines, and Green's team shows such a rope forming and subsequently breaking, causing a CME in December 2007.
The evidence is in an S-shaped formation that can be seen in the extreme-ultraviolet, a shorter set of wavelengths than what our eyes can see. This lends support to theories of CME formation, and possibly gives astronomers a new tool for predicting such energetic events.
More tools are on the way as NASA's Solar Dynamics Observatory is gearing up for scientific observations in a few months. I was lucky enough to wave goodbye to the little spacecraft when it launched from Kennedy Space Center in February, so I'll be eagerly awaiting more science as this solar cycle starts ramping up.
Image: Multi-million degree plasma trapped in a magnetic flux rope in the solar corona as seen by the Hinode spacecraft (JAXA/ISAS/NASA/STFC)
Tags: Astrophysics, Satellites, Space Weather, The Sun
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