Sonic Drive-In is giving customers a galactic experience just in time for the upcoming solar eclipse with the release of its new, limited-edition “Blackout” slush float in stores starting March 25. The new drink features sweet cotton candy and dragon fruit flavors, all-black slush representing the temporary darkness from the solar eclipse and creamy, white soft serve and blue and purple galaxy-themed sprinkles on top. Customers will also get a free pair of eclipse viewing glasses with every “Blackout” slush purchase. “There are over 400 Sonic locations in areas where the total solar eclipse wi…