Space-based telescopes revealing Sun's secrets

 NASA's $817 million Solar Dynamics Observatory has captured images of the Sun's coronal mass ejections, which have mystified scientists for decades. /NASA video via YouTube

With more than 99 percent of solar system's total mass, the Sun is a big story.

The Sun is essential to nearly all life-forms on Earth, but it can make life difficult for spacecraft and electrical grids during the peak of its 13-year coronal activity cycle, which is occurring now. The Sun's corona is the outer solar atmosphere, where solar flares cast radiation into space and coronal mass ejections can spew billions of tons of solar material into the cosmic abyss.

According to NASA, coronal mass ejections:
- draw their explosive energy from violent eruptions of gas and magnetic fields
- send solar materials to Earth in one to three days
- bombard spacecraft with charged particles, prompting the design of shielded safe areas for astronauts
- cause geomagnetic storms in the outer envelope of the Earth's magnetic field, which trigger colorful auroras in polar regions
- can damage or disrupt electrical grids

On Aug. 31, 2012, a long filament of solar material that had been hovering in the sun's atmosphere, the corona, erupted out into space. The coronal mass ejection traveled at more than 900 miles per second. The CME did not travel directly toward Earth, but did connect with Earth's magnetic environment, or magnetosphere, causing aurora to appear on the night of Sept. 3, 2012. /NASA image