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*artist's
drawing |
distance
from the Earth:
384,400 km (center to center)
diameter: 2160 miles = 3476 km
mass:
73,480,000,000,000,000,000,000 kg
temperature: -292 F to 266 F
any rings? no
synodic period (from new moon to new moon):
29.531 days
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Scientists think that the moon has a small iron rich core that used to
be molten (hot liquidy stuff), but is now solid. This is surrounded by a
layer of iron rich rocks that we call the plastic asthenosphere.
(Plastic here just means non-rigid.) Then there is the lithosphere which
is just more rocks - only less dense (less stuff there.) Finally, on the
surface is the crust. The cool thing is that we've actually BEEN to the
moon and brought home a bunch of moon rocks and moon dirt from this
crust! |
No. There's nothing to breathe - not
even poisonous stuff and there's no water to drink. There is some ice
though, but it would be really hard to get to. (We'll talk about that under
"Other Cool Stuff.") Also, the moon is way too hot in the
daytime and way too cold at night. One of the reasons for this is that
the days and nights are both really long. This gives the moon lots of
time to heat up during the day and lots of time to get cold at night.
However, the moon would be a VERY good place for a space station! Maybe
you'll be the one to figure out how to get to the ice and make it nice
drinking water!
To escape the Moon's gravity and get
out into space, a rocket has to travel at a speed of 5,400 mph or 2.4
km/sec. That's only about 83 times faster than your parents are allowed to
drive on a U.S. highway!
As the moon travels around the Earth,
it rotates very slowly... In fact, it rotates at just the perfect speed
so that it keeps the same side pointed towards the Earth at all times!
So, when you look up at the moon, no matter when you look, you'll always
seen the same face.
Our
tides (high tide and low tide) are partially caused by the moon's
gravity pulling on the Earth. (The Sun helps a little with the tides too.)
It
would take 50 moons to fit inside the Earth! (Check out how many Pluto's
(not the dog) fit inside the Earth.)
Twelve
astronauts have gotten to walk on the moon! Neil Armstrong was the
first. These moon missions happened between July 1969 and December 1972
and we haven't sent anybody up there since.
The
moon has no magnetic field (it's not a magnet) and nothing much has
changed on it's surface for about 3 billion years. There are big dark
areas on the moon (that you can see if you look up) that are called
maria (not like the name - it's pronounced MAR-ee-uh). Maria is latin
for sea, since they look like big dark oceans. But, they are really huge
old lava flows.
Most people
don't know this, but there are big lakes of frozen ice on the moon! Yes,
that means water!! In 1994 and again in 1998 we had an unmanned space
craft fly by the moon and they found evidence that there are lakes in
ice in the very bottom of some really deep basins (kind of like a
canyon.) They think that comets may have crashed into the basins a long
time ago and just didn't melt. Since sun light can never reach the
bottom of these basins, the temperature down there could be as low as
-369 F... This is as cold as Pluto!! There may be as much as
300,000,000 tons (600,000,000,000 pounds) of ice up there.
Sources:
In Quest of the Universe, 2nd ed. by Karl F. Kuhn
Voyages Through the Universe, 2nd ed. by Fraknoi, Morrison and Wolff
Universe by Kaufmann
The Complete Idiot's Guide to Astronomy by Christopher De Pree and Alan
Axelrod
The Astronomy Cafe by Sten Odenwald
