A filament ~50 Earths in length (~400,000 miles) erupted from the Sun’s southern hemisphere in the southwest direction around 7:24 UT (4:24 am EDT).
The eruption produced a Coronal Mass Ejection or CME, traveling ~915 km/s or ~2 million mph. Here is a look at the CME in the SOHO/LASCO C2 instrument with Earth for scale. The sun is shown with a composite image of SDO 304 and 193 angstrom wavelength cameras.
The next two images show snapshots of the CME in composite images with SDO and SOHO/LASCO C2/C3. The first frame is at 8:48 UT and the second one is at ~13:30 UT both on 8/20/2013. The bright object on the right in C3 (blue image) is Mercury and Regulus on the left.
NASA SWRC simulations indicate the CME leading edge will reach Earth on 8/22/2013 around 23:11 UT (7:11 pm EDT) +-7 hours. It could produce a minor geomagnetic storm along with aurora visible at higher latitudes.
credit: NASA/ESA/SOHO/SDO and helioviewer