Solar System Debris: Comets, Asteroids, Meteoroids, Meteors

What is Solar Debris?

After birth of the Sun; debris was blown outwards
Much of the debris eventually fell back into the Sun, if its trajectory was correct
Other debris, has enough outward energy to break free of the Sun’s gravity, began to drift in orbit around the Sun

Comets: Dirty snowballs
Made of dust trapped in water, carbon dioxide, methane and ammonia
Consist of solid mass body called the Nucleus
Most comets orbit BEYOND Neptune’s orbit in EDGEWORTH KUIPER BELT & OORT CLOUD
375 + large bodies (100s km in diameter) found in EK belt called TRANS NEPTUNIAN OBJECTS (TNOs)
Some comets move close to sun in Elliptical orbits (visible in night sky)

Once in Jupiter’s orbit- sun MELTS comet’s icy surface
Forms: COMA
Cloud of gas & dust that expands
Solar winds push material into space, causing dramatic tails that may extend millions of kms
As it moves away from sun, tail can PRECEDE comet
At closest point to sun , they are as WIDE as Jupiter!
(i.e Halley’s Comet: Returns every 76 years; named after Edmund Halley discovered the comet. Last one was in 1986, Next one would be in 2062

Asteroids- solid rock like masses that are leftover material from solar system formation
IRREGULARLY SHAPED as most are less than 1km in diameter and they have no gravity
Thousands of asteroids in solar space; two largest are CERES and PALLAS (1000km)
Asteroid Belt: Lies between Mars and Jupiter.
Revolves in the same direction as the planets
65 million years ago, collisions led to the extinction of dinosaurs
Ceres, is about the size of Texas.
They can contain water, iron, silicates, gold, lead, and uranium.
If Jupiter were further out in it’s orbit , the asteroid belt between Mars & Jupiter probably would’ve formed a Mercury-sized planet.
Both of Mars’ moons, and at least 10 of Jupiter’s are probably captured asteroids.
The first manned mission to deeper space may not be Mars – but to an asteroid.
There’ve been at least 3 extinction events on Earth due to asteroid strikes.
We’ve only had one probe ever to orbit & land on an asteroid – Eros, about the size of Manhattan Island.
Asteroids have their own moons.

Meteoroid- Rock/ Icy fragments travelling in space.
Different from asteroids because they are smaller in size (less than 100m in diameter).
About 5 to 15 visible meteoroids per hour
Estimates state around million to a billion enter Earth’s atmosphere but they are so small that burn/vaporize in the air.

Meteor are lights made by meteoroids as it passes through Earth’s atmosphere.
Caused by friction between the rapidly moving meteoroid and the atmosphere.
Meteor Shower: Large numbers of meteors that streak across the night sky in within a few hours.
When earth passes through a comet’s tail; particles from the tail plunge through the atmosphere.
Predictable since comets pass through Earth’s atmosphere at the same time each year.
Perseid Meteor Shower
Meteorites
Meteorites- part of large meteoroids that survive trip through the atmosphere and strikes Earth’s surface
3 types of meteorites
94%= STONY (Earth’s dark igneous rock) Silicates
5%= IRON (Large crystals, little nickel)
1%= STONY- IRON (molten silicate with molten metal)
Most meteorites found in Antarctic Cap