Astronomy and Cosmology Quiz

The Universe

• Astronomy encompasses everything observable, or whose effects are detectable.
• The universe consists of space, matter, and energy.
• Major components include galaxies, solar systems, and planets.

Cosmology

• Cosmology is the branch of astronomy that studies the origin, large-scale properties, and evolution of the universe.

Big Bang Theory

• This theory posits that the universe originated from an explosion of space, time, matter, and energy.
• It's estimated the expansion began approximately 13.7 billion years ago.
• Early expansion was from an extremely small point, to the size of our solar system in a fraction of a second.

Edwin Hubble

• Discovered other galaxies beyond our own, the Milky Way.
• Noted that galaxies are moving away from each other, supporting the Big Bang Theory.
• Hubble's Law demonstrates the relationship between a galaxy's distance and its recession velocity, a further galaxy moves away faster

Arno Penzias & Robert Wilson

• Accidental discovery of faint radiation emanating from a radio telescope in 1965.
• Confirmed this residue as leftover thermal energy from the Big Bang.

Galaxy

• A galaxy is a large collection of stars, gas, and dust.
• They contain billions or even hundreds of billions of stars.
• Galaxies form through the gravitational attraction of their constituent stars.
• Most large galaxies have supermassive black holes at their centers.
• They can be spiral, elliptical, or irregular.
• Formed around 200 million years after the Big Bang.
• There are approximately 100 billion galaxies in the observable universe.

3 Types of Galaxies

• Spiral: Have spiral arms of stars, gas, and dust emanating from the galactic center. Our Milky Way is a spiral galaxy.
• Elliptical: These are shaped like spheres or eggs, with little or no gas or dust between the stars and are primarily composed of older stars.
• Irregular: Galaxies lacking a discernible shape, often smaller than other types.

Constellation

• A constellation is a pattern formed by stars in the sky, viewed as grouped, though often these stars are very distant.
• Astronomers divide the sky into 88 constellations.
• Patterns change over time due to the dynamic nature of stars.
• A group of stars within a constellation that forms its own pattern is called an asterism.

Solar System

• The solar system consists of the Sun and all the objects that orbit it.
• These include planets, their moons, asteroids, and comets.
• Formation dates back 4.6 billion years ago.

Planet

• A planet is a celestial body that orbits a star.
• There are eight planets in our solar system.
• The word "planet" has Greek origins, meaning "wanderer."

Asteroids

• Asteroids are small, rocky bodies that orbit the Sun.
• Many asteroids are located in the asteroid belt, between Mars and Jupiter.
• They are remnants of the solar system's formation.

Meteoroid, Meteor, Meteorite

• Meteoroid: Solid debris in space.
• Meteor: A streak of light produced when a meteoroid enters Earth's atmosphere.
• Meteorite: A meteoroid that survives its passage through the atmosphere and lands on Earth's surface.

Comet

• A comet is a small body of ice and dust that orbits the Sun.
• Comets have a coma, or head, and a tail of gas and dust that points away from the Sun.

Satellite

• A satellite is an object that orbits a larger object, such as a moon orbiting a planet.
• Artificial satellites, launched by humans, orbit Earth.

Telescope

• A telescope is a device used to gather and view electromagnetic radiation.
• Types include:
  • Visible: Telescopes that gather visible light.
  • Reflecting: Telescopes that use mirrors to reflect light.
  • Refracting: Telescopes that use lenses to focus light.
  • Radio: Telescopes that detect radio waves emanating from space, unaffected by weather.

Hubble Space Telescope

• A reflecting telescope that was placed into Earth orbit in 1990.
• Sends images and measurements back to Earth electronically.

Astronomical Unit (AU)

• A unit of distance, equivalent to the average distance between Earth and the Sun.
• Approximately 150 million kilometers or 93 million miles.

Light Year

• The distance light travels in a vacuum in one year.
• About 9.5 trillion kilometers or 6 trillion miles.

Parsec

• A unit of distance that is approximately 3.26 light-years.

Parallax

• The apparent shift in position of an object when viewed from different locations.
• Used by astronomers to determine distances to objects.