The Difference Between a Comet, an Asteroid, and Meteors
Comets are cosmic snowballs of frozen gases, rock, and dust that roughly make up the size of a small town. If you live in or know of a small town near you, that can be a pretty big comparison. Comets do not have any moons or rings and they orbit the Sun. They form an atmosphere or coma, when they get closer to the Sun and begin to warm up.
When you see a Comet you will notice that it has two tails, a white colored tail, which is made up of dust and a blue colored tail, which is made up of electrically charged gases. Astronomers believe that Comets are leftovers from gas,dust, ice, and rock that formed the Solar System about 4.6 billion years ago.
The physical characteristics of a Comet is the solid nucleus or core, (the head) which is mostly ice and dust. As a Comet gets closer to the Sun the ice turns to gas, forming a cloud known as a coma (the tail). The nuclei of a lot of Comets measure from ten miles or less and some have comas that reach 1million miles wide and reach 100 million miles long.
The first Comet was found by a German astronomer named Gottfried Kirch on November 14, 1680. This was considered the Great Comet of 1680. Not only is he the founding father of the first Comet, he also is known as having published series of calendars. Kirch lived from 1639 to 1710.
The most famous Comet that everyone has heard of is Halley's Comet. This Comet is named after Edmond (Edmund) Halley, who examined reports of a Comet coming close to Earth in 1531, 1607, and 1682. His reports indicated that these three Comets were actually the same Comet and predicted that the next sighting would be in 1758. Unfortunately, Halley died before seeing if his prediction was true. The next sighting for Halley's Comet will be in the year 2061.
Comet Blanpain was discovered by Jean-Jacues Blanpain on November 28, 1819. It was considered a dead Comet until its recent re-discovery nearly 200 years later in July of 2013. Comet Blanpain will be observed in the skies on August 28th, 2014. It will take 5.32 years to orbit the Sun.
Another Comet which will soon come within the Earth's sight is Comet Siding Spring. This Comet was first discovered by Robert McNaught on January 1, 2013. At the time of discovery it was beyond the orbit of Jupiter and will come very close to Mars on October 19, 2014. Comet Siding Spring will be visible in the Southern Hemisphere with small telescopes or even with binoculars beginning in the middle of September of 2014. The closest approach to Earth will be on October 25, 2014.
The Great Comet of 1680
Asteroids are small, airless rocky worlds that orbit the Sun. Asteroids are too small to be called Planets and are also known as planetoids or minor planets. Asteroids and Comets are similar, with the difference being, Comets have more chemical compounds and has a more egg-shaped orbit than Asteroids.
Many Asteroids have hit the Earth and have the size of less than the Earth's moon. Most Asteroids orbit Mars and Jupiter in a mass ring of more than 200 with the size of 60 miles in diameter and some larger than 3/5 a mile in numbers of 750,000. This is called the Asteroid Belt or Main Belt. Any Asteroid traveling outside this belt is called a Trojan and lie along Jupiter's orbital path.
Asteroids do not have an atmosphere and can not support life. Those that come close to Earth are called Near-Earth Objects. The first Asteroid recorded was by an Italian Astronomer named Giuseppe Piazzi in January of 1801. It was the first and largest Asteroid named Ceres. Ceres orbits between Mars and Jupiter and is considered the only dwarf planet in our solar system and ranges somewhere around 600 miles in diameter. Now, that's a large Asteroid.
On June 30, 1908, a small Asteroid about 120 feet or more in diameter exploded over the remote region of Tanguska in Siberia. This Asteroid destroyed more than half a million acres of forest land. The most recent close call of an Asteroid here at Earth was in February 2013 when Asteroid 2012 DA14, came as close as 17,000 miles from Earth. Wow, that was a close call. The next Asteroid to come close to Earth won't be until August of 2032, says a team of Ukrainian astronomers. Don't forget to mark your calendars, this might be the big one.
Asteroids come in three categories:
C-Type (Carbonaceous) which include more than 75 percent of any known Asteroid. C-Type Asteroids inhabit the Main Belt's outer region.
S-Type (silicaceous) which include about 17 percent of any known Asteroid. S-Type Asteroids inhabit the Main Belt's inner region.
M-Type (metallic) which include the rest of the known Asteroids. M-Type Asteroids inhabits the middle of the Main Belt's region
It is believed that an Asteroid of six miles in diameter hit the Earth 65 Million years ago causing the distinction of the dinosaurs. But that is still in debate.
An early warning tracking system for Asteroids called NEAT, which stands for Near Earth Asteroid Tracking system, allows astronomers at NASA to track Asteroids. NEAT went on-line in December of 1995 and in March of 1996 came their first discovery of an Asteroid. The NEAT camera is installed on a 39 inch telescope operated at the Summit of Mt. Haleakala by the U.S. Air force.
Meteors are small bodies of matter from outer space that enters the Earth's Atmosphere becoming luminous as a result of friction and appearing as a streak of light in the sky. They are also known as Falling Stars, Shooting Stars, Meteorites, and Meteoroids. Remember the old nursery rhyme "Star Light, Star Bright"?
Before Meteors enter the Earth's Atmosphere they are called Meteoroids. Which means that they are just small pieces of ice, rock, metal, and specks of dust traveling through space. They become a Meteor when they hit Earth's Atmosphere and if they survive the travel and hit Earth they become a Meteorite.
There are three types of Meteorites, stony, iron, and stony-iron. Stony Meteorites are made up of minerals, iron Meteorites are made up of iron and nickel, and stony-iron Meteorites are made up of both minerals and metals.
The largest Meteorite found on Earth was in Nabibia in 1920. It weighed approximately 119,000 pounds and is named Hoba. This Meteorite is so large and heavy that is can not be moved and is still in the same place that it fell in 1920.
Meteorites look very much like the rocks here on Earth, but have a dark, burned exterior. That dark, burned exterior is because of the Meteor falling through Earth's Atmosphere. Meteorites crash onto every planet and moon, not just Earth. Over 60,000 Meteorites have been found here on Earth. When a Meteorite falls onto Earth they sometimes leave a crater upon impact. Most Meteors enter Earth's Atmosphere and disintegrate.
The best preserved impact sight is in Winslow, Arizona. The crater is 6 miles wide and 750 feet deep. It is believed that a meteorite weighing 300,000 tons hit approximately 50,000 years ago. If you want to find meteorites, travel to the Antarctica, this is where the vast majority of Meteors fall to. Don't forget your scarf and gloves.
You can go just about anywhere in the United States to view Meteors in the sky. Just head outside of your town or city where the lights don't obscure your view. Bring a blanket and lie down and watch Mother Nature's light show in the Heavens.