Two massive solar flares have been recorded by NASA over the past two months, and we get to see images and footage of them today.
NASA's Interface Region Imaging Spectograph (IRIS) has been monitoring the sun for activity since the summer, focusing on the chromosphere -- a layer of the sun's atmosphere that regulates the flow of energy and material from the solar surface into space. When energy passes through the chromosphere it warms the chronosphere, the upper atmospheric layer, and can cause solar flare-ups like the one below.
The spectograph separates light into different wavelengths which correspond to materials at different density, temperatures, and velocities. By examining the footage, scientists can learn more about how materials flow at different temperatures and how flares work more generally. NASA reports that researchers had to be strategic in directing IRIS to focus on the right portion of the solar surface:
IRIS can't look at the entire sun at the same time, so the team must always make decisions about what region might provide useful observations. On Jan. 28, scientists spotted a magnetically active region on the sun and focused IRIS on it to see how the solar material behaved under intense magnetic forces. At 2:40 p.m. EST, a moderate flare, labeled an M-class flare – which is the second strongest class flare after X-class – erupted from the area, sending light and x-rays into space.
According to the Science Recorder, scientists know that solar flares are made up of electrons, ions, protons and other high-energy particles, but not much else:
The intense light emitted from the flares consists of radiation across the entire electromagnetic spectrum, including gamma rays, and x-rays. But scientists still don’t know precisely what causes them.
That flare was witnessed on January 28, but another x-class solar flare went off yesterday. Spaceweather.com reports that "this is the most intense flare of 2014 so far, and one of the most intense of the current solar cycle."
Spaceweather.com adds that we're lucky the explosion is off the "sun-Earth line," explaining:
Radio emissions from shock waves at the leading edge of the CME suggest an expansion velocity near 2000 km/s or 4.4 million mph. If such a fast-moving cloud did strike Earth, the resulting geomagnetic storms could be severe. However, because its trajectory is so far off the sun-Earth line, the CME will deliver a glancing blow, at best, and probably no blow at all.
According to Slate's Phil Plait, the sunspot that emitted the flare was first seen in January and has survived through today, and could make another appearance soon:
This sunspot is coming back around now. Over the next week the Sun’s rotation will bring it back to the center of the Sun’s disk, before once again sweeping it around to the Sun’s far side. We’ll have to keep our eyes on this one. A big flare can block radio transmissions, damage satellites, hurt astronauts in orbit, and (on the plus side) create dramatic aurorae. Let’s hope for the latter, but not the three former!
The moon saw some action of its own yesterday, with the biggest lunar explosion ever seen. Guess it's rough out there for a moon or a star.