Science: Thirty Seconds

A 19th-Century stargazer once said that Mercury "seems to exist for no other reason than to throw discredit on astronomers." Last week the little planet (diameter 3,100 miles) was scheduled for a transit across the blazing face of the sun. From complicated formulas and tables, scientists had carefully determined the time. But when astronomers at Mt. Wilson's famed observatory shot the passage with motion-picture film synchronized with a clock, they found Mercury was 30 seconds late for its performance.

Transits of Mercury are a means of charting its queerly complicated orbit. The long...

Want the full story?

Subscribe Now


Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!