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.
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.
