An 1865 painting by Frederic Edwin Church, possibly inspired by the aurora of 1859.
On September 1, 1859, the sky erupted in color: “alternating great pillars, rolling cumuli shooting streamers, curdled and wisped and fleecy waves—rapidly changing its hue from red to orange, orange to yellow, and yellow to white, and back in the same order to brilliant red,” read a New York Times account. This was the aurora seen around the world.
Meanwhile, the telegraph operators were perplexed to find that the system suddenly failed. None of the lines worked, and telegraph paper spontaneously caught on fire. The aurora and disconnected telegraphs were both the working of the largest solar storm recorded in history.
Auroras on Saturn form like those on Earth, when charged particles in the solar wind stream down the planet’s magnetic field towards its poles, where they excite gas in the upper atmosphere to glow. Some auroras on the ringed planet are also triggered when some of its moons, which are electrically conducting, move through the charged gas surrounding Saturn. [New Scientist]
They went to investigate solar wind-stirred storms in our planet’s magnetic field, but, after working for three years, two NASA solar-powered probes faced a dark demise, trapped in the Earth’s shadow. NASA researchers now think they can give the twin satellites another shot by altering their courses and sending them instead to study the moon.
NASA launched the probes in 2007 as a set of five identical satellites in the THEMIS Mission (Time History of Events and Macroscale Interactions during Substorms), meant to orbit Earth and send information during brief (2-3 hour) “substorms” when the magnetic field surrounding the Earth releases stored energy from solar winds. To understand the start of these “space tornadoes” responsible for the northern and southern lights, NASA placed the probes in very precise orbits, but for two craft that meant, one day, they would face prolonged battery-draining time in the Earth’s shadow.
“When we realized that the satellites would be going into very deep shadows, we started thinking of different methods for saving them–even before they were launched,” lead scientist Vassilis Angelopoulos, at the University of California, Berkeley, told Discovery News. “We realized that if we had enough fuel to change their orbits, the moon’s gravity would start pulling them up.”[Discovery News]