Our Universe

Almost two-thirds of the earth’s
surface is covered by water. If the earth were flat, water would cover
everything in a layer two miles deep!



During
a solar eclipse, the shadows of leaves make the same crescent shape of
the eclipsing sun. The image is made by light passing through tiny
holes in the leaves.



Monks
in the 16th century recorded seeing a giant explosion on the side of
the Moon. It most likely was a large meteor that slammed into the Moon
and left a large crater. It was a good thing the Moon was between us
and the meteor!



Is
Pluto the ninth planet or the eighth from the sun? The answer is both.
For most of its 248 year orbit around the sun it is the ninth planet.
But for 20 years of its long orbit, Pluto is actually closer than
Neptune. From 1979 to early 1999, Pluto moved inside the orbit of
Neptune and became the eighth planet!



See
the rings of Saturn while you can. They slowly wobble up and down over
the years as Saturn’s poles point away from then towards the sun. The
rings disappear when edge on to our line of sight. Currently they are
almost at their widest point and can be seen even in binoculars and
small telescopes.



A
star has been found moving closer to the sun. In a million years a star
named Gliese 710 will have moved to within 6/10ths of a light year from
the sun. This is more than six times closer than today’s nearest star,
Alpha Centauri, which is over 4 light years away.



Stars
viewed through even the largest telescopes look like tiny points of
light. But astronomers, using the Hubble Space Telescope to photograph
a star called Betelgeuse (pronounced "beetle jooze"), have now been
able to see the surface of another star. Betelgeuse is a red, giant
star located at the left shoulder of the constellation Orion and is the
largest known star in our galaxy.



Not
all stars are found inside galaxies. Astronomers have found stars
moving between the galaxies, which are millions of light years apart.
These stars may even have planets, possibly with intelligent life on
them. If they do, these beings would see a lonely sky with just one
star (its own sun) and a few faint galaxies.



Tired
of the cold weather? Take a vacation on the hottest planet in the solar
system - Venus. At over 800°, it is hotter than Mercury because the
clouds and abundant carbon dioxide hold in most of the heat received
from the sun.



Ever
notice on a map how the South American and African coasts, along the
Atlantic, fit together like two pieces of a giant puzzle? That is
because at one time, millions of years ago, they were one continent.
Magma from deep in the Earth broke through thin places between these
continents and pushed them apart. They are still slowly moving apart
and the Atlantic ocean is growing wider.



The
lead in pencils, really graphite, is made of the exact same thing as
diamonds. Both are pure carbon which just formed under different
pressures and temperatures. Intense heat and pressure form the carbon
atoms into crystals making diamond, while lesser heat and pressure form
the carbon into sheets making graphite.



Geologists
have discovered there seems to be more water miles deep between the
rocks of Earth’s mantle than in all the oceans of the world. The
intense pressure of the tons of rocks above keeps the hot water from
turning to steam and escaping.