Shooting starsCometsAsteroids

Introduction, I will be going over these three points. •Meteoroids•Comets•Asteroids

•Shooting Stars•Meteoroids•Meteor•Meteorites

Most the meteoroid streams come from comets, comets originate in interstellar space, where they are assembled in the dense molecular clouds of gas and dust between the stars.

The smallest debris in our solar system that can be observed by the naked eye are known as meteoroids. They vary in size from large fragments of asteroids and comets to small micrometeoroids.

Once the meteoroid comes in contact with Earths atmosphere it’s known as a meteor.

A shooting star is a meteoroid. When a meteoroid gets caught in Earths gravitational pull and is forced into our atmosphere.

This leaves a trail of electrons that are negatively and positively charged called Ions. When this happens energy is released in the form of light.

Pulled in by Earths gravitational pull, the meteor is moving at such a fast rate that it knocks electrons out of atoms into the atmosphere.

Meteoroids do not always come alone. Every once in a while earth gets to see a celestial event called a meteor shower. Several if not hundreds of meteoroids are pulled into Earth’s gravitational pull, at extremely high speeds and on parallel trajectories.

Meteor showers are generally named after the constellation in which they appear to originate. Leonids being from the constellation, Leo.

There have been some very significant meteor showers recorded. Such as the Leonids, “the king of showers”. Which happens every thirty three years around November seventeenth. It usually produces thousands of meteors per hour.

A large one of note is the Barringer crater located, in the Northern Arizona desert. It is one of the biggest and most well preserved crater on Earth. (5,709 ft) above sea level, and about (4,000 ft) in diameter.

Not all meteors are small debris, they come in all shapes and sizes and the bigger ones leave a mark.

There are two different types of Meteorites. Primitive- Where the components form independently and were not part of a larger object.

If the meteor survives earths atmosphere and lands it’s called a meteorite.

Processed- Which are large fragments from a preexisting asteroid. Which it’s composition is due to differentiation.

Comets

A comet is an icy body, that releases gas or dust. A comet consists of a solid nucleus, Surrounded by a cloudy atmosphere called the coma and one or two tails.

It is believed that comets are leftover debris from a collection of gas, ice, rocks, and dust that formed the outer planets about 4.6 billion years ago. Some scientists believe that comets originally brought to Earth some of the water and the carbon-based molecules that make up living things.

Most of the comets that can be seen from Earth, are the ones that travel around the sun in long, oval orbits. The bigger portion of comets can’t be seen by the naked eye and have to be seen via telescope. The ones that we can see, can be seen because of the gases and dust in their comas and the tails reflect sunlight. Also the comets gases absorb energy from the sun, causing them to glow!

Comets are classified by the length of time it takes to orbit the sun, short period comets take less that 200 years to complete one orbit. While long period ones take 200 years or longer.

The French astronomer, Nicolas Louis de Lacaille named the comet “Halley’s Comet” in his honor when it returned on schedule proving his theory.

People have been naming comets for century's, though one of the first people to notice that some comets come back to the inner solar system periodically, was Edmund Halley. He discovered a short period comet that would seem to come back every seventy-five to seventy-six years.

Some comets get within a few thousand kilometers of the sun’s surface. These are called sun grazers. The small comets will be completely broken up and evaporated. While many of them get evaporated some larger ones can survive getting that close. However with the tidal forces from the sun, they break apart into fragments.

Asteroids

There are a lot of theory's surrounding where asteroids came from. One of which states that they came from a planet that suffered a massive collision.

Asteroids are rocky metallic objects that orbit around the sun, but are too small to be considered a planet. They are known as planetoids. Asteroids can be the size of one thousand km, or even a pebble.

• C-type, includes more than 75% of known asteroids: extremely dark; approximately the same chemical composition as the sun accept for the hydrogen, helium and other volatiles.

Asteroids are classified into a number of type according to their spectra.

•S-type, 17%: relatively bright; metallic nickel-iron mixed with iron- and magnesium-silicates.

•M-type, most of the rest: bright; pure nickel-iron. There are some other rare types.

Over half its mass is due to some of the largest planetesimals known, like, Ceres, 4 Vesta, 2 Pallas, 10 Hygiea.

Located roughly between the orbits of planets Mars and Jupiter is an asteroid belt. Which is a constellation of numerous asteroids. This particular belt is dubbed the main asteroid belt.

Ceres is the only planetesmial that is large enough for its gravity to force it into a spherical shape. According to IAU’s resolution on the definition of a planet, Ceres is now considered a dwarf planet.

In time the other three large asteroids might become dwarf planets as well. Over time their gravity with force them into a spherical shape.

Ceres 4 Vesta 2 Pallas 10 Hygiea

The United States of America, has a NASA program called the near Earth object program, their goal is to monitor anything that looks like it could possibly collide with Earth and cause catastrophic damage. Recently there was speculation that Earth would have a asteroid the size of a soccer field hit it at around February 1st 2019. Luckily this speculation was recently updated with good information stating, with more observation of the asteroid 2002 NT7’s path, that we would escape collision. They are continuing to keep close observation on this asteroid.

In conclusion, a side from being extremely fascinating. Using the information we get from meteoroids, comets, and asteroids, we are able to further our knowledge on of the endless void that is our solar system. And keep the Earth out of harms way.

THE END

Questions?

http://www.nasa.gov/worldbook/comet_worldbook.html

http://space.about.com/cs/asteroids/a/asteroidimpact.htm

http://www.solarviews.com/eng/meteor.htm

Book-Cosmic Perspective, The (5th Edition)

Sources