Perseid Meteor Shower 2011 - Photo by CNN |
I did take a little time while I was sick to visit a region of our universe that has always intrigued me and that is outer space. I spent a few evenings out on the deck wrapped in a blanket to catch the Perseid Meteor shower. According to CNN's blog August 11 "Hundreds of shooting stars and fireballs will fill the skies over the northern hemisphere on Saturday and Sunday night as Earth passes through a stream of debris from the Comet Swift-Tuttle - otherwise known as the Perseid meteor shower."
Looks like Drumheller but it's Mars courtesy of the JPL |
Here's some more cool thoughts on space and the darkness that surrounds us.
Asteroids
From the Hubble Telescope courtesy of the Discovery Channel |
There is a lot of exciting stuff going on in the stars above
us that make astronomy so much fun.
The truth is the universe is a constantly changing, moving, some would
say “living” thing because you just never know what you are going to see on any
given night of stargazing.
But of the many celestial phenomenons, there is probably
none as exciting as that time you see your first asteroid on the move in the
heavens. To call asteroids the
“rock stars” of astronomy is simultaneously a bad joke but an accurate
depiction of how astronomy fans view them. Unlike suns, planets and moons, asteroids are on the move,
ever changing and, if they appear in the night sky, exciting and dynamic.
Like rock stars, asteroids have been given their fair share
of urban myth and lore. Many have
attributed the extinction of the dinosaurs to the impact of a huge asteroid on
the earth. This theory has some
credibility and, if it is true, it evokes some pretty startling images and
foreboding fears in the current reining species on earth, the human race.
The fact that asteroids are fast moving space debris only
makes their movement and activity more interesting and exciting. Unlike a moon, planet or star, the odds
that an asteroid could hit the earth are entirely reasonable and in fact, there
are many documented cases of small asteroids making it through our atmosphere
and leaving some pretty impressive craters in the earth’s surface.
Popular culture has happily embraced the idea of an asteroid
impact. The idea has spawned many
a science fiction story adding the idea that alien life forms may ride asteroids
to our world and start a “war of the worlds” situation. But by far, the most talked about
concept that has captured the imagination and the fears of science fiction fans
and the general public is of another asteroid hitting the earth that could wipe
out life as allegedly happened to the dinosaurs. In fact, the movie “Armageddon” was based on this idea and
the concept that somehow mankind could avert that catastrophe with technology.
But probably the best way to calm our fears and replace
science fiction with science is with understanding and knowledge. The truth is, there has been a lot of
study of asteroid activity and the serious scientific community has gained significant
knowledge of these amazing celestial bodies. A number of probes to asteroids have been conducted which
have given us a wealth of information about their composition and how we might
predict their behavior.
We now know that the majority of asteroids we get to witness
come from an asteroid belt that exists between Mars and Jupiter. It is from this community of asteroids
that many of the notable asteroids emerged. Scientists have gained significant knowledge about the
composition of asteroids and separated them into classes including class S
which comes of the part of the belt that is closest to Mars, classes C, D and V
which are classified by composition and a class called “Centaurs” whose flight patterns
take them closer to Jupiter and Uranus.
Ida and it's moon Dactyl from Discovery Channel. |
Some of the probes NASA has conducted on near flying
asteroids have performed some pretty amazing studies of these eccentric
celestial bodies. In 1994 the
Galileo probe got within 1000 miles of the asteroid Ida and discovered that Ida
actually had its own moon.
Other probes have fired impactors into asteroids and even
landed on an asteroid to produce some amazing scientific data for us. There is much to learn about asteroids
in our love of astronomy and that knowledge only makes our enjoyment of seeing
them in the cosmos even more exciting.
Until our next space adventure, have a great week. Dave