Last month I talked about the heat of the sun, about 93 million miles away. On August 12 a spacecraft left Earth on a mission that will take it as close as four million miles, streaking through the sun’s corona (the vapor-like “crown”) at the record speed of 120 miles per second. The science equipment and electronics onboard would melt in minutes, if not protected from radiation and the intense heat by a special shield.
That spacecraft is called the Parker Solar Probe, named after the University of Chicago astrophysicist who understood, 60 years ago, how particles are ejected from the corona and reach Earth as a “solar wind.” Happily, Eugene Parker, now 91 years old, was able to be at Cape Canaveral in August to see the launch of “his” solar probe.
When these particles reach us, the upper atmosphere glows with the beautiful changing colors of the aurora, also known as the northern and southern lights.
The new spacecraft will travel in elliptical orbits around the sun, swinging out to Venus and back ever closer to the sun until 2025. The instruments will measure the particles in the solar wind, map electric and magnetic fields, and make images of the corona. The aim of the mission is not just cool science (it is cool, even though it’s hotter than hell). We will learn how extremely violent sun storms can eject giant blobs of charged particles that reach our planet about a day after emission.
In 1859 a giant solar storm emitted a blob that engulfed Earth, causing compass needles to flicker and telegraph systems across America and Europe to fail. Some operators even got electric shocks. The aurora was seen as far south as Mexico and Hawaii. An equally powerful solar storm happened in 2012, but luckily the most intense radiation missed Earth. The next one that hits us – and some day one will – could take out power grids causing month-long black-outs, killing satellite communications and shutting down the internet.
I would not like to be in an airplane when that happens. But by monitoring the activity on the sun with solar probes and ground-based observatories, we could get a few hours’ warning and ground all airplanes, deliberately shut down power grids, and do whatever is necessary to minimize the damage. Then these solar probes will be worth their weight in gold many times over. We must be prepared.