Our Own Moon
Take a look at the far side of our own Moon and it becomes obvious pretty
quick that the Earth has a goalie out in space. Thousands and thousands
of impact craters suggest that stuff out there comes our way on a pretty
regular basis. Take a look too at sites on Earth such as Meteor Crater
in Arizona or Manicougan crater in Northern Quebec. This crater is
so large that it can only be seen properly from space. Unlike the Moon,
erosion tends to wipe out evidence of impacts over time, but some remain.
Barringer ("Meteor Crater") in Arizona
49,000 years ago, a crater nearly a mile in diameter and nearly 600'
deep was formed when an object traveling at 40,000 miles per hour slammed
into the ground in what is now the state of Arizona. The object that made
this crater was 150 feet across and weighed roughly 300,000 tons. The force
generated by its impact was equal to the explosion of 20 million tons of
TNT. Debris from the impact was scattered in a radius of 8 to 10 miles
all around the crater. It is believed the object vaporized on impact --
small particles have been found in the crater which suggest this.
Manicougan Crater in Northern Quebec
(*Note: This is so large -- 62
miles across -- that it can only be seen well from space.
Estimated age: 200 Million years.)
A recent study suggests that should an object only six tenths (0.6) of
a mile in diameter strike the Earth, such an impact would create global
havoc. At this writing, it is believed that at least 900 such asteroids
exist in this or larger sizes and many cross the Earth's orbit from time
to time, thus presenting a potential threat to the Earth. Right now, the
asteroid designated 2004-MN4 is projected to pass within 15,000 to 25,000
miles of the Earth in the year 2029. The asteroid will pass so close that
it is believed the Earth's gravity could alter its orbit in such a way
that the asteroid could impact the Earth as soon as 2035. 2004-MN4 is about
0.2 miles in diameter. There are no known Near Earth Asteroids (NEA) large
enough to actually break the Earth into pieces. There are, however, many
which if they strike the Earth could make the planet uninhabitable. But
don't keep looking up at the sky. An Earth dweller is 20 times more likely
to be killed in an automobile accident than by an impact from an asteroid.
So please keep your eyes on the road.
Here is our Moon. The arrow points to an asteroid that can't really be
seen in this size image. This object is about 20 miles long and 12 miles
wide. But what if this same object were much larger, say 750 miles long
and 250 miles wide? This is the size of the object which hits the Earth
shortly after group #317 is launched into space.
It is possible that 65 million years ago, a killer asteroid struck the
Earth in the vicinity of what is now the Yucatan Peninsula in Mexico. When
it did, material thrown up into the atmosphere reduced sunlight and dropped
the global temperature to near freezing. In the end, roughly half of all
species on the planet had perished -- including the dinosaurs. Could we
be next on the list?
Here is a gravity and magnetic map of what is believed to be the remains
of the crater from the killer asteroid. The crater is located beneath the
Gulf of Mexico and the northern tip of the Yucatan Peninsula, near the
Mexican village of Chicxulub (pronounced Cheek-shoe-lube, a Maya phase
for "horns
of the devil".) The age of the Chicxulub crater, dated at 65 million
years, corresponds to the demise of the dinosaurs. Chicxulub could be as
large as 180 miles across, one of the largest in the inner solar system
and large enough for the associated impact to create global extinction.
ASTEROID LINKS:
Impact
Events - Wikipedia
Asteroid/Comet
Impact Craters and Mass Extinctions
Barringer
(Meteor) Crater - Arizona
Earth
Impact Events - Everything you ever wanted to know
Terrestrial Impact
Craters
Near
Earth Asteroids - Distant Star E-Zine
Earth
Threatening Asteroid Orbits - Impact Risks
Take a look at the far side of our own Moon and it becomes obvious pretty
quick that the Earth has a goalie out in space. Thousands and thousands
of impact craters suggest that stuff out there comes our way on a pretty
regular basis. Take a look too at sites on Earth such as Meteor Crater
in Arizona or Manicougan crater in Northern Quebec. This crater is
so large that it can only be seen properly from space. Unlike the Moon,
erosion tends to wipe out evidence of impacts over time, but some remain.49,000 years ago, a crater nearly a mile in diameter and nearly 600'
deep was formed when an object traveling at 40,000 miles per hour slammed
into the ground in what is now the state of Arizona. The object that made
this crater was 150 feet across and weighed roughly 300,000 tons. The force
generated by its impact was equal to the explosion of 20 million tons of
TNT. Debris from the impact was scattered in a radius of 8 to 10 miles
all around the crater. It is believed the object vaporized on impact --
small particles have been found in the crater which suggest this.(*Note: This is so large -- 62
miles across -- that it can only be seen well from space. Estimated age: 200 Million years.)
Here is our Moon. The arrow points to an asteroid that can't really be
seen in this size image. This object is about 20 miles long and 12 miles
wide. But what if this same object were much larger, say 750 miles long
and 250 miles wide? This is the size of the object which hits the Earth
shortly after group #317 is launched into space.It is possible that 65 million years ago, a killer asteroid struck the
Earth in the vicinity of what is now the Yucatan Peninsula in Mexico. When
it did, material thrown up into the atmosphere reduced sunlight and dropped
the global temperature to near freezing. In the end, roughly half of all
species on the planet had perished -- including the dinosaurs. Could we
be next on the list?Here is a gravity and magnetic map of what is believed to be the remains
of the crater from the killer asteroid. The crater is located beneath the
Gulf of Mexico and the northern tip of the Yucatan Peninsula, near the
Mexican village of Chicxulub (pronounced Cheek-shoe-lube, a Maya phase
for "horns
of the devil".) The age of the Chicxulub crater, dated at 65 million
years, corresponds to the demise of the dinosaurs. Chicxulub could be as
large as 180 miles across, one of the largest in the inner solar system
and large enough for the associated impact to create global extinction.
Asteroid/Comet Impact Craters and Mass Extinctions
Barringer (Meteor) Crater - Arizona
Earth Impact Events - Everything you ever wanted to know
Terrestrial Impact Craters
Near Earth Asteroids - Distant Star E-Zine
Earth Threatening Asteroid Orbits - Impact Risks
