From the skies of Earth, Jupiter and Venus will have their
closest association tomorrow, appearing just a few degrees
apart. Actual separation is more than 400 million miles. But it
made me think about even closer encounters in the sky. Don’t
forget Venus transits the sun later this year, in June. (2004′s
imaged, right) What about a planet transiting another planet?
Does that ever happen? Sure does. Last time was 1818. But we’ve
got a long wait for the next one. In fifty-three years, the
brightest two planets will appear to merge in the sky, and
Venus, through a telescope, will appear to cross the face of
Jupiter as seen from Earth. Something in my lifetime will be the
December 2020 encounter of Jupiter and Saturn. They will appear
to merge in the sky. In a small telescope’s view, you’ll be able
to see two planets and five moons.