The sun emitted a significant solar flare on Oct. 19, 2014, peaking at 1:01 a.m. EDT. NASA’s Solar Dynamics Observatory, which is always observing the sun, captured this image of the event in extreme ultraviolet wavelength of 131 Angstroms – a wavelength that can see the intense heat of a flare and that is typically colorized in teal.
This flare is classified as an X1.1-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 flare is twice as intense as an X1, and an X3 is three times as intense.
Solar flares are powerful bursts of radiation. 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.
Like a drop of dew hanging on a leaf, Tethys appears to be stuck to the A and F rings from this perspective.
Tethys (660 miles, or 1,062 kilometers across), like the ring particles, is composed primarily of ice. The gap in the A ring through which Tethys is visible is the Keeler gap, which is kept clear by the small moon Daphnis (not visible here).
This view looks toward the Saturn-facing hemisphere of Tethys. North on Tethys is up and rotated 43 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2014.
The view was acquired at a distance of approximately 1.1 million miles (1.8 million kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 22 degrees. Image scale is 7 miles (11 kilometers) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
The sun got into the Halloween spirit a little early this year, producing active spots that look like a jack-o’-lantern leer on October 8. The active spots give off more light and energy than the rest of the sun’s surface.
This visualization shows the sun’s activity in two wavelengths of light, 171 Angstroms and 193 Angstroms. Both wavelengths are in the extreme ultraviolet portion of the electromagnetic spectrum, which is what NASA normally studies.
Extreme ultraviolet light isn’t visible to the naked eye, but it can nevertheless affect human life. When the sun is particularly active, the high-energy photons of extreme UV light can heat the Earth’s atmosphere, creating additional drag on mankind’s orbiting satellites. Or the photons can break apart atoms and molecules in the atmosphere, creating ions that disrupt radio signals. Luckily for life on Earth, the atmosphere blocks most extreme ultraviolet light from reaching the planet.
by Francie Diep
Active Regions on the Sun, October 8, 2014 NASA/GSFC/SDO