MINOR MEMBERS OF THE SOLAR SYSTEM

• NEAR Shoemaker: Feb 2001, 1st asteroid landing on Eros. Originally for orbit, provided data for asteroid deflection. Not designed for landing, touched down at 6 km/h.
• Asteroids:

  • Often called "flying mountains"
  • Largest is Ceres, ~1000 km diameter
  • Most are only ~1 km across
  • Smallest like grains of sand
• Asteroids:

  • Ceres discovered by Giuseppe Piazzi
  • Typically found between Mars and Jupiter
  • Orbital periods of 3 to 6 years
  • Some have eccentric orbits, come close to the sun, Earth, and the moon
• Asteroids:

  • Often irregularly shaped
  • Speculated to be fragments of a broken planet between Mars and Jupiter
  • Total mass estimated to be 1/1000 of Earth's mass
• Main Asteroid Belt: Located between Mars and Jupiter.

  Trojan Asteroids: Some asteroids orbit ahead and behind Jupiter.

  Near Earth Objects (NEOs): Asteroids that approach Earth closely.
• Comets: Fascinating and unpredictable celestial bodies.

  Composition: Rocky, metallic materials with frozen gases like water, ammonia, methane, and more.

  Orbits: Some have elongated orbits extending beyond Pluto, taking hundreds of thousands of years to orbit the sun, some with shorter periods regularly approach the inner solar system.
• Long-Period Comets: Return every 200 years or more.
• Short-Period Comets: Return in less than 200 years.
• Near the sun, frozen gases vaporize, forming a glowing head called a coma.
• Comet tails near the sun come in two types: dust tails, formed by solar wind pushing out particles, and plasma tails, made of ionized gas.
• Comets come from two regions: Short-period ones likely originate from the Kuiper belt beyond Neptune, while all comets orbit the sun like planets.
• Oort Cloud - 50,000 au from the sun, has trillions of comets (long-term), comets are dark, carbon-rich
• Meteoroids - space debris that, entering the atmosphere, collide with gases, produce bright streaks of light known as meteors or shooting stars.
• Big and unusually bright pieces of meteors

  are called fireballs.
• METEOR SHOWER- a spike in the number of

  meteors or "shooting stars" that streak through the night

  sky
• METEORITES-the remains of the meteoroids found on the

  surface of the earth.