Interesting Facts About
Asteroids
Asteroid Belt
Asteroids
are group of minor planets or lumps of rocks revolving
around the sun in the asteroid belt lying between the orbits of Mars
and Jupiter. Astronomers believe that there are more than 12 lacs
asteroids in the asteroid belt. Of which 1 lac asteroids are more than
1 Km wide. These things are mainly composed of rocky core, icy mantle
and minerals like iron and nickel. The first and largest one, named as
Ceres, was discovered in the year 1801 which has a diameter of 936 Km.
Since then thousands of them have been discovered and 38 among them are
more than 200 Km wide. Pallas, Juno, Vesta, Hygiea, Davida,
Interamnia and Europa are some other largest asteroids in the group.
The asteroid named Vesok is the brightest one and it can be seen with
our naked eyes.
How The Asteroid Belt Could Have
Been Formed in the Solar System?Asteroids are
thought to be the primoridal objects left over from the formation of
solar system. Astronomers are believing that the formation of planets
could be from the nebula gas and dust particles that evolved from the
sun and later the dust particles formed into a disk revolving around
the sun. All the dust particles and gas coagulated with each other to
form smaller and larger bodies called planetesimals, many of which
eventually accreted into planets over a period as long as 100 million
years. However, the gravitational force of giant planet Jupiter
prevented futher accretion of planetesimals lying between the orbits of
Mars and Jupiter into larger planets. Thus these mini solar bodies have
become as asteroids in our solar system.
Asteroid
Crashing to EarthEvery
day tiny asteroids in various sizes are continuously hitting our earth.
Asteroids will get the name meteorites after entering into the earth's
atmosphere. Our earth would get serious impacts only if the asteroids
in larger size crashed on it. Generally asteroids which likely to crash
on earth would travel at a high speed of 20 to 25 Km/second. When these
ateroids enter the upper atmosphere of earth at such a high speed, due
to friction with the air, most part of the asteroid will burn and break
up into many pieces over the large area of the sky. In fact, the
burning and disintegration of the asteroids after entering into the
upper atmosphere of our earth is merely responsible for the safety our
earth. Incase it was not happened, we could not imagine the series of
impacts that our earth might get from the asteroids.
The impact on earth is depending upon the
mass, after disintegration, of asteroid at the moment of crashing to
earth. It has been calculated by the astronomers that any asteroid
having dia of 1 Km at the moment of crashing to earth would release the
explosive power of 100 billion tonnes of TNT which would make serious
global and greenhouse effects.
It is estimated by
the astronomers on average one asteroid larger than 0.4 Km crashes
earth every 50,000 years. About 65 million years ago a 10 Km wide
asteroid crashing to earth may have been responsible for wiping out of
dinosaurs. That great astronomical event would have caused catastrophic
explosion affecting climate and chemical composition of global
atmosphere, mega tsunamis with incredible height of thousands of ft,
the cloud of super heated dust; steam and other particles would have
covered entire atmosphere of earth for a decade blocking sunlight and
destroying strange plants and mighty animals like dinosaurs.
Asteroid
CratersThe
powerful crashing of asteroids in the span of millions and millions of
years have caused many craters on the surface of our earth. These are
indeed most interesting part of geological structures of our earth as
they have special concave appearance. In our beautiful globe there are
more than hundreds of asteroid craters and 45 of them are said to have
importance. Many asteroid craters have been eroded and gone down to
earth. Let us see some interesting asteroid craters on our
earth.
1. Barringer Crater
It is located in northern Arizona desert of USA and named
after
Daniel Barringer who was first person to suggest that that was an
asteroid crater. About 4000 ft diameter and 570 ft deep Barringer
Crater would have been created by the impact of 150 ft wide asteroid
some 50,000 years ago. The astronomers suggested that the asteroid
would have struck the point at the speed of 20 Km/second. It can be
seen even today.
2.Chicxulub
Crater This is one of the most interesting
craters as it could have been responsible for the extinction of
dinosaurs and other mighty animals and plants from the earth. This is
located near Chicxulub village in Mexico of North America. It would
have been created by the impact of 10 Km wide asteroid some 65 million
years ago. This is so huge with 170 Km diameter and it has gone down to
earth. That asteroid impact could have created great changes in global
atmosphere which could have been the reason for the extinction of
animals like dinosaurs.
3.Gosses
Bluff Crater
This is found in the center part of Australia continent. This
is 24
Km wide and has gone 5 Km down to earth. This could have been created
by the impact of 22 Km wide asteroid crashed earth at a speed of 40
Km/second some 140 million years ago. These days we can see only the
highly eroded part of the crater.
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