The Sun is still very much alive and kicking: It emitted two extremely powerful bursts of radiation today — a pair of X-class solar flares within about an hour of each other. You can see both of them in this video from NASA's Solar Dynamics Laboratory. The X-class designation is reserved for the most powerful of solar flares. Here is another view showing the entire Sun.

And here's a really cool still image, also from the SDO spacecraft:

An X-class flare erupts from the sun on June 10, 2014, as imaged by NASA's Solar Dynamics Observatory spacecraft. (Source: NASA) The colors are different in the videos and the image above because each views the sun in different wavelengths. Do these flares pose a risk to us Earthlings? As NASA put it on the Solar Dynamics Observatory Facebook page this morning:

Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground. However, when intense enough, they can disturb the atmosphere in the layer where GPS and communications signals travel.

According to the Space Weather Prediction Center, the flares were strong enough to cause some disruption of high frequency radio communications, which, among other applications, are used for communications between aircraft and the ground. (The potential impact from the flares were classified as "R3" on the NOAA Space Weather Scale. For more information about that, go here.) I haven't found any reports of actual disruptions to communications yet. If I find any, I'll report back.

The number of sunspots, a measure of solar activity, hit a second peak in March, as seen in this graph of the entire solar cycle so far. (Source: Space Weather Prediction Center) The sun is at the height of its activity cycle right now, as seen in the graph above. According to the space weather center: