The Solar System (Planetary Debris)
Charles Modequillo
Aiko Olaer

Planetary Debris
• During the formation of the Solar System not everything became the planets and the moons. There are other remnants from the solar nebula that are called planetary debris.
These are what we know as asteroids, meteoroids and comets.

Asteroids
• planetary debris made up of chunks of rocks and metals that orbit around the Sun. They are also called planetoids
• planetary debris made up of chunks of rocks and metals that orbit around the Sun. They are also called planetoids
• compose only a fraction of the Solar System

Types of Asteroids
• C – Type
• S- Type
• M - Type

C- Type
• Carbonaceous (largely carbon, dark)
• Consist 75% of the asteroids
• Outer orbits

S- Type
• Silicate (largely silicon, light)
• Consist 15% of the asteroids
• Inner orbits

M- Type
• Nickel-iron
• Consists about 10% of the asteroids

Examples of Known Asteroids
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•
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Ceres
• Largest asteroid
• 940 km diameter
• 1/10,000 of the mass of Earth’s moon

Gaspra
• S-Type asteroid
• Maximum diameter of 20 km
• About 200 million years old

Ida
• S-Type asteroid
• Maximum diameter of 60 km
• About 1 billion years old

Comets
• Comets are icy matters that follow elliptical orbits around the solar system. As they approach the Sun, comets heat up, emit radiation and also develop a tail.

Parts of a Comet

Nucleus
• Solid portion of the comet
• 1 to 10 km in diameter
• Density of 100 kg/m 3

Coma
• Evaporated gas and dust forming a halo around the nucleus as the comet approaches the Sun

Hydrogen Envelope
• Hydrogen gas that surrounds the coma of the comet and trails along for millions of miles

Dust Tail
• Up to 10 million km long composed of smoke-sized dust particles driven off the nucleus by escaping gases
• Broad, diffuse, curved, less deflected by solar wind

Ion Tail
• Straight out, blown by solar wind
• Several hundred million km long composed of plasma and laced with rays and streamers caused by interactions with the solar wind

Orbits
• Having a highly elliptical orbit means that there is point for each comet where it is closest to the Sun. At this point we call that a comet is at its perihelion. There is also a point where the comet is farthest from the sun, this point is called aphelion.

Orbits
• A period is the time taken by a comet to travel once around the Sun in its orbit.
Comets are often classified according to their orbital periods.

Period of Orbits
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•

Short Period Orbits
• From Kuiper Belt
• Have orbital periods of less than 200 years
• 30 to 50 AU (Astronomical Unit) in diameter

Long Period Orbits
• From Oort Cloud
• Orbits up to 100,000 AU in diameter
• Periods ranging from 200 years to thousands or even millions of years
• Surrounds Sun in all directions

Kuiper Belt and Oort Cloud

Halley’s Comet
• First predicted by Edmund Halley to reappear in 1758
• last visible from Earth in the year 1986
• has been orbiting the Sun since 240 BC

Halle-Bopp
• Discovered in July 1995
• Was visible to the naked eye in
• Perihelion on April 1, 1997
• Period of about 4000 years

Meteoroids
• are small bits of rock or metal or ice that are chipped off asteroids or comets. They are debris floating in space outside the Earth’s atmosphere. On the other hand, meteors are meteoroids on the process of entering the
Earth’s atmosphere. They are also known as
shooting stars.

Meteorites
• are pieces of a meteoroid that successfully lands on Earth. These meteoroids are the ones responsible for cratering the inner solar system.

Types of Meteorites
• Iron
• Stony Iron
• Chondite
• Carbonaceous Chondrite
• Achondrite

Iron
• primarily iron and nickel similar to type M asteroids

Stony Iron
• mixture of iron and stony material like S type asteroids

Chondite
• similar in composition to the mantles and crusts of the terrestrial planets

Carbonaceous Chondite
• very similar in composition to the Sun less volatiles, similar to type C asteroid

Achondrite
• similar to terrestrial basalts, the meteorites believed to have originated on the Moon and Mars are achondrites

A very large number of meteoroids enter the
Earth's atmosphere each day. The largest found meteorite (Hoba, in Namibia) weighs
60 tons.

The average meteoroid enters the atmosphere at between
10 and 70 km/sec. But all but the very largest are quickly decelerated to a few hundred km/hour by atmospheric friction and hit the Earth's surface with very little fanfare. However meteoroids larger than a few hundred tons are slowed very little; only these large
(and fortunately rare) ones make craters.

Barringer Crater
• A crater near Winslow, Arizona
• Was formed around 50,000 year ago
• Formed by a 30-50 meter diameter iron meteor.
• Crater is 1200 meters in diameter, 200 meters deep

Meteor Showers in the Philippines

Geminids
• The Geminids meteor shower is an annual event. Its recent peak was observed in the
Philippines last December 14 th of 2011.
They appear to radiate from the constellation Gemini.

Leonids
Leonids is an annual meteor shower the generally begins on Nov 13 and ends on November 17. It occurs annually at the time of the year when the
Earth passes through streams of debris left behind by the Tempel-Tuttle comet.

Upcoming Meteor Showers for 2012

Lyrids Meteor Shower
• Will occur late night of April 21 until dawn April
22 and the night of April 22 until dawn of April
23
• rate of 10 to 20 meteors per hour
• outbursts up to 100 meteors per hour

Others
ETA Aquarids
May 5 to 6
Delta Aquarids
July 28 and 29
Perseids
Dawn of August 12 or 13

References: http://manila-paper.net/geminids-meteor-shower-peak-tonight-december-
14/21299 http://www.meteorwatch.org/2011/11/11/leonids-meteor-shower-2011/ http://newsinfo.inquirer.net/breakingnews/nation/view/20091105-
234291/Spectacular-meteor-shower-forecast-on-Nov-17 http://earthsky.org/astronomy-essentials/earthskys-meteor-shower-guide http://physics.uoregon.edu/~jimbrau/astr121/Notes/Chapter14.html

References: http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/debris.htm
http://astro.unl.edu/classaction/outlines/solarsystemdebris/ss_debris.html
http://en.wikipedia.org/wiki/Comet http://nineplanets.org/comets.html
http://cse.ssl.berkeley.edu/segwayed/lessons/cometstale/frame_orbits.html

References: http://www.bobthealien.co.uk/cometshal.htm
http://nineplanets.org/meteorites.html
http://stardate.org/astro-guide/ssguide/meteorites http://en.wikipedia.org/wiki/Hoba_meteorite