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Shooting stars Comets Asteroids.

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Presentation on theme: "Shooting stars Comets Asteroids."— Presentation transcript:

1 Shooting stars Comets Asteroids

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

3 Shooting Stars Meteoroids Meteor Meteorites

4 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. 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.

5 A shooting star is a meteoroid
A shooting star is a meteoroid. When a meteoroid gets caught in Earths gravitational pull and is forced into our atmosphere. Once the meteoroid comes in contact with Earths atmosphere it’s known as a meteor.

6 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. 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.

7 Meteoroids do not always come alone
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.

8 There have been some very significant meteor showers recorded
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. Meteor showers are generally named after the constellation in which they appear to originate. Leonids being from the constellation, Leo.

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

10 If the meteor survives earths atmosphere and lands it’s called a meteorite.
There are two different types of Meteorites. Primitive- Where the components form independently and were not part of a larger object. Processed- Which are large fragments from a preexisting asteroid. Which it’s composition is due to differentiation.

11 Comets

12 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. 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.

13 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. 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!

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

15 Some comets get within a few thousand kilometers of the sun’s surface
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.

16 Asteroids

17 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. 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.

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

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

20 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. Ceres 4 Vesta 2 Pallas 10 Hygiea In time the other three large asteroids might become dwarf planets as well. Over time their gravity with force them into a spherical shape.

21 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 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.

22 In conclusion, a side from being extremely fascinating
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.

23 The end

24 Questions?

25 Sources Book-Cosmic Perspective, The (5th Edition)


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