Tomorrow, you’ll have a once-in-a-lifetime opportunity to
actually see a planet cross over a star. Venus transits our sun
for the last time in over a century at 22:09 UTC, June 5th, so
find a way to watch. Why is this so special? If you have any
astronomer friends, they’ve probably been blabbering on for
months about orbital periods this, first contact that. Why won’t
we shut up? Because this is literally once in a lifetime, and
it’s kinda cool. Venus, the next planet inward, will cross
directly over the visible disc of the sun. It will appear as a
tiny black dot, about one arcminute, covering a minuscule
fraction of the disk. This isn’t a lot, but it’s enough to see
with the naked eye—not the recommended way to view it, of
course. Venus’ orbit is slightly skewed compared to Earth’s, so
Earth, Venus, and the sun only line up this way every 121.5 or
105.5 years. After this much time, Venus gets in the way of the
sun twice, each time eight years apart. The last transit was
eight years ago. The next, after tomor