Grab your erasers, there are more moons
than we thought
We spend so much of our blog discussing the sun & wind and their importance to their respective renewable energies, I thought it might be interesting to get some fun facts out to you regarding moons. Yes, you read that right, moons. After all, tonight is the first night of the full moon.
Quick: What's the total number of moons orbiting planets in our
solar system?
Don't worry if the answer's not on the tip of your tongue, but it's
still the Trivial Pursuit sort of question that's fun for a water cooler
session.
If the last time you checked was more than a week ago, your answer
will be incorrect. Not to keep you in suspense, the answer is 178 moons.
Granted, that number includes the 5 moons of Pluto, which has been demoted to
dwarf planet status, so we now speak of our solar system's eight planets, not
nine. Still, it has moons, and even as a dwarf planet it is still considered
part of our solar system.
The point to note here is that the answer to the "how
many" question would have been different just a short while ago; just last
week astronomers announced an analysis of existing Hubble telescope images and
data revealed a new moon orbiting Neptune, bringing that blue-green planet's
total to 14.
Moons in our solar system have fascinated us since Galileo used
his primitive telescope to discover the first one -- four in fact, orbiting
Jupiter.
Since Galileo, moon discovery has been an ongoing effort by
astronomers, as last week's news aptly demonstrated.
Mercury and Venus, our close neighbors between us and the sun,
have no moons. Astronomers suggest it's
their very proximity to the sun that is the reason; any moon orbiting beyond a
certain distance eventually would be "kidnapped" by the greater
gravitational pull of the sun, while any closer would crash down into the
planets. The zone of distance where a moon could exist in a stable orbit is
thought to be so narrow that neither Mercury nor Venus managed to ever capture
one.
Earth has only managed one, of course, but it's a solar system
standout because of its size. There are larger moons out there, but in relation
to the size of its planet our moon is impressive, being slightly more than a
quarter the size of Earth, a ratio seen nowhere else in the solar system.
Mars has two moons, both are believed to be asteroids captured and
pulled into orbit by Mars.
Jupiter, when it comes to a moon count, leads the solar system
pack with 67, including the largest moon in the solar system, Ganymede, larger
than Mercury and three times larger than Earth's moon. Saturn's not far behind
with 62, many of them tiny moonlets of less than 30 miles in diameter. Uranus clocks in with 27 known moons.
And we end with Neptune and its
new moon. Its discovery suggests the count will not stop, and the total will no
doubt increase with better telescopes and more space probes voyaging around the
solar system, so by all means offer the 178 figure the next time astronomical
trivia is the subject around the water cooler -- just be ready to amend that at
a moment's notice.
