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 & TNOs

  • 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)

Comet’s tail

  • 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

  • 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.

Meteoroids

  • 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.

Meteors

  • 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

Impact Craters

  • Bowl-shaped depression after meteor strikes the earth
  • Oldest crater named VREDEFORT
  • Rare, only 150 known
  • Earth’s atmosphere burns most meteoroids before striking Earth’s surface
  • Earth is geologically active, often covering the impact craters
  • Ripples in Earth’s surface
  • Reservoirs for oil & gas deposit
  • Arizona’s Barringer Meteor Crater
  • Formed 49,000 years ago
  • Iron meteorite
  • 45m in diameter
  • Carter is 1200m

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