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“Then the fifth angel sounded: And I saw a star fallen from heaven to the Earth. To him was given the key to the bottomless pit.” Revelations 9:1
“Then the fifth angel sounded: And I saw a star fallen
from heaven to the Earth. To him was given the key to
the bottomless pit.” Revelations 9:1
“And he opened the bottomless pit, and smoke arose out of the pit
like the smoke of a great furnace. So the sun and the air were
darkened because of the smoke of the pit.”
Revelations 9:2
Asteroid Impacts
A descriptive overview of past events,
current ideas, and future consequences.
Introduction
Historically
An interesting concept that was not seriously
explored or studied.
Present
Hot topic of debate and concern due to recent
studies.
Future
New Idea?
We knew impacts were
common to our nearest
neighbor.
Assumed that lack of
atmosphere led to very
little protection.
Thus impacts were
more frequent.
New Information
Space probes to other
planets.
Voyager Missions
Saw impact craters on
other bodies.
Satellites around Earth.
Noticed possible sites
here.
Mimas
One of the moons
around Saturn.
Impact crater indicates
that impact was just
below the level needed
to rip moon apart.
Basis for the Death
Star.
Moons Only?
Mercury
Shows signs of
significant impacting in
past.
But once again,
Mercury lacks an
atmosphere.
Natural Protection
Initially thought
atmosphere good
enough protection.
Only few sites
recognized around
globe as impact sites.
Meteor Crater in
Arizona
New Technology, New Sites
Started to locate other sites due to new and improved technology.
Shuttle view of spacestation over Manicouagan, Canada.
Started looking for sites instead of just chance findings.
What are we seeing?
Did not realize a lot of sites on Earth were impact craters.
Views from space improved our information.
Erosion and human activity destroying sites.
Other Sites
Middlesboro, KY.
City built inside
ancient crater.
6 km wide
Over 300 million years
old.
Serpent Mound, OH
Found just north of Ky.
border.
Mound built on just
part of impact ring.
Built about 800 AD by
Native Americans.
Over 320 million years
old.
El’gygytgyn, Russia
Crater has filled with
water over time.
About 3.5 million years
old.
18 km in diameter.
Roter-Kamm, Namibia
Found on African
plains in Namibia.
About 3.7 million years
old .
2.5 km in diameter.
Manicouagan, Canada
Circular lake with town
in middle.
100 km in diameter.
About 214 million
years old.
Wabar, Saudi Arabia
Found in desert.
See people in
background for scale.
About .116 km in
diameter.
Approximately 140
years old.
Wolfe Creek, Australia
Found in Australian
Outback.
About 0.875 km in
diameter.
A little over 300,000
years old.
Tunguska, Siberia
June 30, 1908 at 7:40 in the morning.
Massive explosion in an uninhabited area of Siberian Province of Russia.
Tunguska, Siberia
Asteroid or comet exploded
in the atmosphere at an
altitude of about 6 miles.
Knocked down about 80
million trees.
Shock wave knocked people
off their feet and broke
windows hundreds of miles
away.
Tunguska, Siberia
Blast destruction area
covered 830 square
miles.
Leonid Kulik was the
first scientist to reach
the area in 1927.
Found no crater!
Tunguska, Siberia
Later investigators found microscopic glass spheres.
Chemical analysis revealed high levels of nickel and iridium.
These chemicals are very common in meteorites, but not on Earth.
Chicxulub, Mexico
Found off coast of
Yucatan Peninsula.
About 65 million years
old.
170 km across.
Dinosaur Killer?
Sonar image of sea
floor.
Barringer Crater, AZ
Meteor Crater National
Park
Original finder wanted
to mine iron from
meteorite.
About 3,000 years old.
1.186 km in diameter.
Strings of Impact Craters
So far only looked at single impact sites.
Due to recent evidence, believe that impacts
occur in pairs or strings of multiple impacts.
Evidence from other sites and one on Earth.
Moon String
Found on side of Moon
away from Earth by
Apollo mission.
First clue came from
Shoemaker-Levy 9
Impact.
Shoemaker-Levy 9
Saw asteroid falling
toward Jupiter.
Asteroid broke apart.
Struck Jupiter in a
sequence.
Spread across surface
due to planet rotation.
SL-9 Single Impact
Callisto
Moon of Jupiter
Found by space probe.
Multiple string of
craters.
Clearwater, Canada
Impact pair in Northern
Canada.
Filled with water that
melted as glaciers
receded during last ice
age.
Most asteroids believed
to have companion.
Moon Creation
Often wondered why Earth has such large moon when compared to moons of other planets.
Mars sized object struck Earth, material blown off became Moon.
Hollywood
Recent movies have
increased public
awareness.
Armageddon
Deep Impact
Dinosaur Extinction
Theory of Luis Alvarez
and his son Walter.
Dinosaur Killer
Asteroid had mass of
trillion tons.
Released energy
equivalent to 5 billion
atomic bombs.
Crater 250 km across.
Deep enough to
penetrate thru crust.
Dinosaur Killer
Lifted 100 trillion tons
of dust into air.
Shut off sunlight for
several months.
Global acid rain.
Large-scale fires.
Forests and grasslands.
How Destructive Can It Be?
Speed is critical.
Size of object is
important.
Physical structure of
object plays role.
Location of impact.
Speed
Each time speed
doubles, damage
quadruples.
50 mph = 50 joules
100 mph = ? joules
Answer = 200
Most travel at about 6
miles a second!
Size Does Matter
The more massive an
object, the more energy
it has in it.
Example:
Tractor trailer moving
at 50 mph will do a lot
more damage than a
bicycle moving at same
speed.
Size
< 10 meters
Don’t worry unless directly under it.
10 meters
Rule of Thumb
Crater about 20 times bigger than rock
10m x 20 = 200m crater
Average speed.
Size
100 meters
2 km crater
Equals best
craters from
nuclear
testing.
Size
1000 meters
20 km crater
Secondary
effects become
global
Water Strike
1000 meter asteroid generates about 50 m tall wave.
Rule of Thumb
Wave increases 40x when moves to shallows.
Becomes 2000 m (2km) in shallows.
Cosmic Shooting Gallery
What are the odds of impacts?
What can we do to save ourselves?
Frequency
Pea Size – 10/hour
Walnut Size – 1/hour
Grapefruit – 1/10 hrs
Basketball – 1/month
50m – 1/century
1km – 1/ 100,000 yrs
2km – 1/500,000 yrs
Frequency
Dinosaur type killer
asteroids – 1/50 to 100
million years.
Last occurrence was 65
million years ago.
We are due!
Next Century
Planetary scientists
estimate a 1/1,000
chance of major impact
in this century.
Odds decrease by
factor of 10 each
century.
Potential Threats?
About 2,000 objects of 1 km diameter cross Earth orbit.
10,000 objects at 500 meters
30,000 objects at 100 meters
150 million at 10 meters
What is Being Done?
In order to do anything,
must locate asteroids
and comets.
Spacewatch
University of Arizona
NEAT
Near-Earth Asteroid
Tracking
Spacewatch Project
Steward Observatory
on Kitt Peak.
Robotic telescope
photos sky.
Computer analyzes
images for motion.
Alerts astronomers.
2,000 a month
NEAT
Sponsored by NASA
and U.S. Air Force.
Telescope in Hawaii.
Also uses computers.
Has detected over
10,000 asteroids.
The End?
Location
With current
technology, it is
probable that we could
detect any threatening
asteroid years in
advance.
What can we do?
Small Nudge
The farther away the
asteroid is, the less
energy is needed to
shift its path.
Changing the speed by
1 mph would be
enough.
Earth
Path of an oncoming
asteroid.
Earth
1 Billion Miles Away
Requires only a change
of 1 degree in course!
Earth
500 Million Miles Away
Requires only a change
of 10 degree in course!
Earth
100 Million Miles Away
Requires only a change
of 45 degree in course!
Plan A
Crash a rocket into the
asteroid.
Deflect its course just a
tiny amount.
Probably only good for
small ones.
< 300 ft. wide
Don Quixote
European Space Agency is
studying a design of a space
mission to accomplish Plan
A.
The first “real” asteroid
deflection mission ever
designed.
Plan B
Explode an atomic
weapon near asteroid
in space.
Heat one side causing
material to explode
away.
Newton’s Third Law of
Motion takes effect.
Plan C
Build a rocket engine
on one side of asteroid.
Rocket fires for several
years.
Slowly changes course
over long period of
time.
Problems
All three plans have
problems.
Do not have the
technology yet.
Requires finding
asteroid years in
advance.
Asteroid breaks up!
Future
Is there hope?
Advances in
technology.
Spacewatch and NEAT
programs.
We need to get a
permanent space base
to aid in protection.
Deep Impact 2005
In the Summer of 2005,
NASA accomplished the
Deep Impact Mission.
Sent a probe to comet
Temple 1.
Had a projectile that
struck the comet while the
mother satellite took
photos.
Stated Mission
The stated mission for Deep Impact was to cause matter from the comet to be ejected into space.
Then NASA scientists would analyze the results to see what makes up comets.
Was there another mission?
Other Mission?
Maybe this was a test to see if they could hit a comet or asteroid.
If they are testing it, should we be worried?
Maybe , maybe not?
Do you think the government would tell us if it were coming?
Apophis
Apophis is an Ancient
Egyptian spirit of evil
and destruction,
determined to plunge
the world into total
darkness.
Name of an asteroid
that is of concern to
astronomers.
Apophis
390m wide, discovered in June
of 2004.
In December 2004, odds of
impact were 1 in 37!
On April 13, 2029, this asteroid
will pass pretty close to Earth.
A Friday!
22,600 miles from earth center.
Have ruled out a collision in that
year due to increased tracking.
Apophis
Yet, as the asteroid passes
Earth’s gravity, its course
may be changed, leading to
a possible impact in 2036.
The chances right now of
Apophis hitting the right
course for a collision after
passing Earth in 2029 is 1 in
5,500. Look how close!
Another World Map
Related Books
Hammer of God
About stopping an asteroid.
Lucifer’s Hammer
Life after an impact.
