How accurate do you expect your local weather report to be? Honestly, I'll believe their predictions up to 48 hours, but anything beyond that is pushing it. Now it looks like our ability to predict sunspots is now at that same level, giving us valuable warning time for people in space, and infrastructure on the ground.
Telling the astro-weather is hardly something new. Enthusiasts have been regularly reporting on space weather since 1998, doing what Warren Ellis described as "the Shipping Forecast for space."
What is new is a way of detecting sunspots long before they erupt, bringing some warning to astronauts and sensitive communication equipment that can suffer under the magnetic blasts they cause.
Researchers have been analyzing the Sun using the Solar and Heliospheric Observatory, and they've found they can detect specific magnetic fields 65,000 kilometers below the surface of the Sun. Using Doppler observations, they've spotted "strong acoustic travel-time anomalies", which they've identified as subsurface signatures of sunspots.
These anomalies rise at a rate of 0.3 to 0.6 kilometer per second, bursting to the surface of the Sun one to two days after they're detected, in the form of a sunspot. With 24-48 hours warning, that's enough time to reschedule spacewalks and reroute communications that may be disrupted by the magnetic flux.
Is that the space equivalent of bringing in your drying from the rain?