Astron- The Universe & Galaxies Spring Final Reveiw

Define: Oort Cloud

• Spherical shell of icy bodies, including comets, that surrounds our solar system, located beyond the Kuiper belt and Neptune's orbit.

• A dense region of asteroids located between Mars and Jupiter.

• A group of planets that orbit a distant star outside our solar system.

• A large gas cloud found at the center of the Milky Way galaxy.

Tags

NGSS.MS-ESS1-3

Define: Rotation curve

• Material rotates much faster around the galactic center than Newtonian physics would predict. This leads to the idea that most of the galactic mass is DARK MATTER.

• The path traced by a planet as it orbits the sun in an elliptical shape.

• The change in the color of a star due to its motion relative to Earth.

• The process by which a star forms from a collapsing cloud of gas.

Tags

NGSS.HS-ESS1-2

Define: Hubble's law

• Galaxies farther away from us move farther away from us. The universe is expanding.

• The speed of light is constant in all directions.

• Gravity is the force that keeps planets in orbit around the sun.

• Black holes emit large amounts of visible light.

Define: Spiral galaxy

• Galaxies with a galactic bulge, a disk of material extending away from that in arms that are glowing from star light reflecting off of gas and dust. BLUE STARS dominate the outer arms - young hot stars.

• Galaxies that are completely irregular in shape and lack any distinct features or structure.

• Galaxies that are spherical or oval in shape, containing mostly old stars and little gas or dust.

• Galaxies that are made up entirely of dark matter and are invisible to telescopes.

Define: Local Group

• Group of about 50 galaxies that are locally bound together through gravity. MILKY WAY & ANDROMEDA are the two largest. Andromeda is almost twice as large as our Milky Way.

• A cluster of stars within the Milky Way galaxy.

• A collection of planets orbiting a single star.

• A group of asteroids located between Mars and Jupiter.

Define: Dark matter

• Material that makes up the majority of mass in a galaxy. It helps explain the strange orbital velocities of material far out on a galactic arm.

• A type of visible gas found in nebulae.

• A form of energy that powers stars.

• A type of matter that emits strong electromagnetic radiation.

Define: Dark energy

• Energy responsible for making galaxies outside of local clusters expand outward into the universe.

• A type of matter that forms stars and planets.

• The force that holds atoms together in molecules.

• Radiation emitted by black holes.

Define: Cosmic microwave background

• Left over energy from the Big Bang that shows material distribution to make stars and galaxies as well as evidence of dark energy.

• A type of radiation emitted by black holes in the universe.

• The visible light from the nearest stars in our galaxy.

• A layer of gas surrounding the Earth that protects it from cosmic rays.

Tags

NGSS.HS-ESS1-2

NGSS.HS-PS4-3

NGSS.HS-PS4-4

Define: White-dwarf supernova

• A standard candle that explodes with the same luminosity every time.

• A type of star that forms after a red giant phase.

• A black hole formed from a massive star's collapse.

• A planet that orbits a white dwarf.

Define: Gravitational forces

• Force that dominates a solar system’s movement as well as the binding force for local groups of galaxies to overcome Dark Energy.

• Force that causes chemical reactions between atoms.

• Force responsible for the repulsion between like electric charges.

• Force that allows objects to float in water.

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4