RT @fcain: Watch Mercury Race Across the Sun, Courtesy of the Big Bear Solar Observatory @Astroguyz universetoday.com/128703/watch-m… https://t.co/DlI5o6rZer
RT @fcain: Watch Mercury Race Across the Sun, Courtesy of the Big Bear Solar Observatory @Astroguyz universetoday.com/128703/watch-m… https://t.co/DlI5o6rZer