More 60-Second Science We’re just hours away from the last
transit of Venus until the year 2117. A transit is when a planet
passes in front of the sun, revealing itself as a tiny black dot
on the sun’s face. Transits in the 18th century helped us figure
out the dimensions of the solar system, which are now well
known. But the 2012 transit will still provide information that
could help astronomers understand distant exoplanets. “During a
transit you get a tiny bit of light that passes through the
planet’s atmosphere, if it has an atmosphere. And so, if you
tease that out you then can start doing all kinds of interesting
science on the atmosphere itself.” Mark Anderson, author of The
Day The World Discovered The Sun, about the 18th-century Venus
transits. “So there are going to be telescopes all over the
world, and what they’re all going to be looking for is the about
0.001 percent of the sun’s light that has also passed through
the atmosphere of Venus during the transit. That’s interesting
to astronomers—they