NEOs: A Threat to Mankind

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NEOs A Threat to Mankind
Image source http//www.arm.ac.uk/impact-hazard/D
OOMS_DAY.JPG

• By Josh Throckmorton
• October 15, 2007

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Imagine the scene Youre sitting on the beach
with your family, taking in the warm rays of the
sun on a beautiful, summer day. Not a cloud is in
the sky the breeze off the ocean keeps you
comfortably cool. You dig your feet further into
the sand, feeling the tiny grains sift through
your toes. A seagull squawks in the distance,
water breaks on the shore. Your children are both
bent over by the oceans edge, shovels in hand,
sculpting a sandcastle. The day could not be more
perfect. Suddenly, the sky gets even brighter
and people everywhere start screaming and
pointing up. You put your hand up to block out
the sun and look up. There in the sky, hurtling
directly for you is an asteroid! You run to the
water, grab your kids, and start sprinting to the
parking lot. You make it half way up the beach
when all of a sudden
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impact! They have happened before, and they will
happen again.
An artists rendition of a NEO impact Image
Sourcehttp//cache.eb.com/eb/image?id82787rendT
ypeId4
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Our planet is a dartboard in space. Every day,
about one hundred tons of interplanetary debris
trickles down to the Earths surface. While much
of this is tiny interplanetary dust particles
that pose no danger to life on Earth, every once
in a while, larger and far more dangerous pieces
of space debris collide with the Earths
atmosphere and cause great catastrophes.
65 million years ago An asteroid 10 kilometers
across strikes just off the coast of the Yucatan
peninsula, killing the dinosaurs and sending a
trillion tons of rock and dust into the
atmosphere, creating a cloud the suns light
could not penetrate for a thousand years.
Image source http//images.usatoday.com/tech/_pho
tos/2006/11/07/fossil472.jpg
50,000 years ago An asteroid about 50 meters in
diameter touches down in Arizona, leaving a
crater over a mile wide.
Image source http//www.travelsw.com/southwest-tr
ips/southwest-trips-arizona/meteorcrater.htm
99 years ago A comet fragment measuring 70
meters across explodes about 5 to 10 kilometers
above ground near the Tunguska River in Siberia,
releasing enough energy to have wiped out modern
day Washington DC, while knocking over a
countless number of trees and devastating the
nearby landscape.
Image source http//www.aerospaceweb.org/question
/astronomy/impact/tunguska.jpg
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Near Earth Objects, also called NEOs, are comets
and asteroids that have been pushed and pulled by
the gravitational attraction of nearby planets
into orbits of within 1.3 astronomical units
(about 93 million miles) of the Sun. They are the
left over remnants from the formation of the
solar system, and can be found primarily in the
Asteroid Belt, the Kuiper Belt, and the Oort
Cloud. Even though the terms often get mixed
together when describing interplanetary debris,
comets and asteroids are very different from each
other.
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Comets are clusters of ice and dust that
periodically come into the center of the solar
system. They live in a spherical cloud of icy
debris called the Oort Cloud which lies in the
outskirts of our solar system, almost 50,000
astronomical units (AU) away from the Sun. One AU
is the average Earth-Sun distance. Every once in
a while, as our solar system rotates through the
Milky Way Galaxy, it comes close to another star
whose gravity pulls on the Oort Cloud similar to
the moon on the Earths oceans. This pull can
disrupt the orbits of comets in the cloud,
possibly sending them shooting into the central
part of our Solar system. As the comets get
closer and closer to the Sun, they start to
evaporate and jets of gas and dust form the long
tails we can sometimes see from Earth.
Haleys Comet Image source http//www.koyote.com/
users/bobm/hale-bopp.jpg
An artists rendition of the Oort Cloud Image
source http//www.mkzdk.org/twitcher/bigoort.jpeg
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Asteroids are rocky and metallic objects that
orbit the Sun but are too small to be considered
planets. They range in size from pebbles to 1000
kilometers in diameter, and can be found all over
space, even though they mostly reside in a Main
Belt between the orbits of Mars and Jupiter and
in the Kuiper Belt, which extends from the orbit
of Neptune to 55 astronomical units away from the
Sun. Asteroids are material left over from the
formation of the solar system, and thus their
contents reveal much about the history of our
planet and its neighbors. The vast majority of
NEOs are asteroids, and it is estimated that up
to 1,100 asteroids 1 kilometer in diameter or
larger are floating within our solar system. NASA
plans to find 90 percent of them by the end of
2008.
An asteroid in space Image source
http//www.crystalinks.com/asteroid1.jpg
The asteroid belt is drawn here in white Image
source http//en.wikipedia.org/wiki/ImageInnerSo
larSystem-en.png
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If a large asteroid or comet were to impact
Earth, the results could alter or even end human
history. That is why it is important for us to
locate NEOs and keep an eye on their orbits and
the way they move. Currently, NASA supports the
work of several teams searching for comets and
asteroids 1 kilometer in diameter or larger.
These teams conduct work very similar to what we
do in class they use large telescopes to take
several images of a region of the sky during a
given timeframe, overlap them, and use computers
to search for any moving objects. Typically, a
comet or asteroid will appear as a somewhat
blurry grey dot moving in a constant, straight
path between the pictures. If an object is found,
the astronomers will confirm it by blinking the
images. This further highlights the objects
movement. If the comet or asteroid still appears
to exist, astronomers will then compare their
findings with a database of known objects at the
Minor Planet Center in Cambridge, Massachusetts
to see if their object has been previously
discovered. If the object has never been seen
before, the astronomers record its celestial
coordinates, submit it as a newly found NEO, and
get to name it. This is exactly what the Fall
2007 NMH Astronomy class was doing when students
discovered 4 new asteroids. The class also
submitted the coordinates on numerous other
asteroids for which data was requested by the
Minor Planet Center. The Near Earth Object
recovery project that we were a part of was
created by Bob Holmes at the Atronomical Research
Institute http//ari.home.mchsi.com/ Please see
this site for more info.
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NMH Fall 2007 Asteroid Discoveries
By Yidan Li K07TN8K , K07T73P , K07T73O By H.
Pack and Yidan Li K07T15N
The picture below shows the current position and
orbit of K07TN8K
Orbit diagrams and parameters can be found at the
following website by typing in the objects
designation and clicking Submit Query
http//neo.jpl.nasa.gov/orbits/
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Currently there are only a few NEOs that pose a
serious threat to life on Earth. The asteroid
1950DA has a 1 in 300 chance of hitting our
planet in the year 2880. It is 1.1 kilometers in
diameter and could cause large scale and possibly
global damage if it did impact Earth. However,
not enough information is currently available to
say it will impact Earth for sure.
Asteroid 1950DA Image source http//upload.wikime
dia.org/wikipedia/commons/thumb/b/ba/1950da_color_
150.jpg/120px-1950da_color_150.jpg
The asteroid Apophis (2004 MN4, 320 meters in
diameter) is projected to come very close to
Earth in the year 2029. Fortunately, information
gathered by amateur and professional astronomers
in December 2004 and January 2005 has revealed
that an impact is unlikely.
An artists rendition of Apophis Image source
http//www.ufodigest.com/images/apophis.jpg
As of January 2007, there were 832 known
asteroids 140 meters in diameter or larger that
had orbits within 0.5 astronomical units of the
Earths orbit around the Sun. An impact will
happen again, but with the human race being so
advanced, there may be something we can do about
it.
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There have been several proposed theories about
how we humans might be able to prevent or at
least survive an NEO impact in the future. One
idea is to demolish the object in space, breaking
it into smaller pieces that will either burn up
in the Earths atmosphere, cause less damage upon
impact, or miss the planet all together. The
problem with this theory, though, is that the
flight patterns of the smaller fragments will be
unpredictable, and so even if there are five
smaller chunks that would only wipe out the
populations of the land they hit and not the
entire human race, those five smaller chunks
could theoretically hit the five most populated
places on Earth, causing major losses.
Another idea is to send a heavy spaceship up to
collide with the NEO in space and bump it out of
orbit. This idea appears to be the safest, though
we currently do not have the technology to
produce a rocket large enough to bump most
potentially dangerous asteroids out of their
orbit.
One idea for how to avert an impact would be to
send up a spaceship to bump a NEO out of its
orbit Image source http//media.npr.org/programs/
atc/features/2005/nov/asteroid/asteroid200.jpg
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A third and final plan for how to survive a NEO
impact would be relocation of some members of the
human race. While we are currently nowhere near
having the technology to do so, possible
locations include Mars, the moon, and large space
stations orbiting around the Earth. This is an
idea for the worst-case-scenario, but it may have
to become a reality someday.
Image source http//files.myopera.com/leirom/file
s/MoonInflatableHabitat.jpg
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NEO impact has ended life on Earth before. If we
are to protect ourselves from this kind of
disaster, it is imperative that we find NEOs
before they enter Earths atmosphere. Much like
here at NMH, an astronomy class at the University
of Washington in Seattle has been looking to the
skies as well. There, five students looking for
supernovae discovered a cluster of over 1,300
previously undetected asteroids. These newly
found NEOs now account for about 1/250th of all
known objects in the solar system. The NEOs,
which were originally discovered in 2005 and 2006
but have just been verified by the Minor Planet
Center, do not pose an immediate threat to Earth,
though many have orbits close to Earths and may
cross our planets path in a few thousand of
years. With the discovery, the students involved
will now be able to name about 260 asteroids
each.
The white arrow points to one of the 1,300 new
asteroids discovered by five University of
Washington students Image source
http//www.komotv.com/news/local/10319697.html
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The news of this discovery is excellent. One of
the biggest problems we as humans may face with
NEOs in the future is that we may not detect the
one that impacts Earth because we are not looking
for it. NASA supports the work of only about five
teams across the country searching for NEOs. As
stated in the movie Armageddon, beg'n your
pardon sir, but it's a big-ass sky. Space is
larger than our minds can fathom, and it grows
every day. Five or so teams cannot possibly cover
all of that sky with their telescopes every
night, and even if they do, they may still miss
something. The fact that college students, and
even that we as high school students, are getting
involved in the search to save humankind is
remarkable. We are not just learning from
textbooks about astronomers who look for these
kinds of things, but we are getting to experience
the real thing and contributing to science
ourselves. And who knows? Maybe well be the next
to find 1,300 NEOs that could possibly cross
paths with the Earth.
Just by looking up, even we as students can
contribute to science and the hunt for NEOs Image
source http//www.acseal.freeserve.co.uk/comet/co
met1.jpg
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Near Earth Objects- comets and asteroids floating
around our solar system- pose a very real threat
to the existance of mankind. Our planet is a
dartboard in space, and we have been made a bulls
eye before. By better understanding NEOs and
being able to lend our knowledge to the search
for them, we may be able to prevent a world-wide
catastrophe. As proven by the five University of
Washington students who recently discovered 1,300
NEOs, you dont have to be a professional to
contribute to science. Through our class
contribution to NEO research, maybe well be able
to preserve the status of humankind and keep the
skies clear on that beautiful, summer day on the
beach. All we have to do is look up.
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Image souce http//www.wallpaperbase.com/wallpape
rs/space/earth/earth_6.jpg