Week 7: Solar System

 Lab






WEEK 7: SOLAR SYSTEM

  • Our Solar System

  • The Milky Way 

    • Galaxy: a collection of billions of stars, gas, and dust held together by gravity in space

    • Solar System: located in the Milky Way Galaxy 

    • The Milky Way is a large spiral-shaped galaxy which contains hundreds of billions of stars

    • At the center of the Milky Way is a supermassive black hole named Sagittarius A (mass of 4 million suns)

    • Our Sun, Earth, and planets are located halfway between the center and the outer edge on a small partial arm called the Orion Spur 

    • There are 8 planets in our solar system: 

      • Mercury 

      • Venus 

      • Earth 

      • Mars 

      • Jupiter

      • Saturn

      • Uranus

      • Neptune 

      • ACRONYM (closest to farthest from the sun) = My Very Educated Mother Just Served Us Nutella

    • Four inner planets (Mercury, Venus, Earth, Mars) are rocky planets because they have a solid surface

    • Four outer planets (Jupiter, Saturn, Uranus, Neptune) are gaseous planets because they are composed of gases, mainly hydrogen & helium 

    • Rocky planets are much smaller in size, gaseous planets are larger 

      • Theory for this: when the Sun turned on and became a star, it caused the gas clouds of the 4 inner planets to blow away and the rocky planets were left with a smaller, solid planet 

      • Gaseous planets are farther from the sun, so they retained their composition

      • As they increased in mass = gravity increased = allowed them to attract more and more material from space and grow larger in size 

  • Why is Pluto not a planet? 

    • Was the 9th planet in our solar system until 2006 decision to be a dwarf planet

    • Meets the 2 requirements to be a planet: 

      • Orbits around the sun

      • Its gravity formed the planet into a round shape 

    • Does not meet the 3rd requirement: 

      • Clearing the neighborhood

      • Planets must have gravitational dominance and clear the neighborhood around their orbit

        • Means that large planets (more mass = more gravity) either attract or eject other, smaller bodies from that region of space 

      • Several other dwarf planets and similarly-sized space objects were discovered in the solar system near Pluto’s orbit in the Kuiper Belt, so Pluto has not cleared the neighborhood & cannot be considered a planet 

  • Asteroids 

    • Dust & rocks in space were pulled together by gravity to form planets

    • Rocky remnants (that didn’t make it into a planet) called asteroids remain and orbit the sun in our solar system

    • Main asteroid belt = between Mars & Jupiter, where most known asteroids orbit 

  • Other objects in the Solar System

    • Comet: A frozen ball of gas, rock, and dust that orbit the Sun. When a comet gets close to the Sun, it heats up and the gas and dust form a tail.

    • Meteoroid: A small rock in space that orbits around the Sun. Most meteors have broken off of larger objects such as asteroids or comets. They can be as small as a grain of sand or as large as a pickup truck.

    • Meteor: The streak of light that is caused when a meteoroid enters Earth’s atmosphere and burns up due to friction. Also known as a shooting star.

Meteorite: A meteoroid that survives its trip through the atmosphere and lands somewhere on Earth. The impact of a meteorite can cause a crater on the surface of a planet.

Comments

Post a Comment