Unit 1: Introduction to Astronomy , Unit 2: The Solar System

Astronomy

Study of space stuff like stars, planets, and galaxies.

Planetary Astronomy

Study of planets, moons, and more to see what they're made of and if they could have life.

Stellar Astronomy

Study of stars: how they're born, live, and die.

Galactic Astronomy

Study of galaxies: how they form, move, and interact.

Cosmology

Study of the whole universe: how it started (Big Bang), how it changes, and what will happen.

Ptolemy

Old Greek thinker who thought Earth was the center of everything.

Galileo Galilei

Made telescopes better in the 1600s and found cool stuff in space.

Isaac Newton

Made better telescopes and figured out gravity.

Hubble Space Telescope

Super strong telescope in space that sees galaxies far, far away.

Observational Astronomy

Collecting space data by looking at space with telescopes.

Optical Telescopes

Telescopes that use light to see stars, planets, and galaxies.

Refracting Telescopes

Telescopes that use lenses to bend light.

Reflecting Telescopes

Telescopes that use mirrors to focus light, made by Newton.

Radio Telescopes

Telescopes that use radio waves to study space.

Infrared Telescopes

Telescopes that see infrared light, usually in space.

Altazimuth Mount

Telescope holder that moves up/down and side to side.

Equatorial Mount

Holder that follows stars as Earth turns, good for watching for a long time.

Solar System

The Sun and everything going around it: planets, moons, asteroids, and comets.

Sun

Big, hot, glowing ball of gas in the middle of our solar system.

Inner Planets

The four rocky planets closest to the Sun: Mercury, Venus, Earth, and Mars.

Outer Planets

The four big gas and ice planets far from the Sun: Jupiter, Saturn, Uranus, and Neptune.

Mercury

Smallest planet, closest to the Sun, super hot and no air.

Venus

Second planet from the Sun, thick air of carbon dioxide, very hot.

Earth

Planet with water and air where we live.

Mars

The Red Planet, with a big volcano and canyon.

Jupiter

Biggest planet with a big red spot and lots of moons.

Saturn

Planet with beautiful rings of ice and rock.

Uranus

Gas planet that spins sideways and looks blue-green.

Neptune

Farthest planet, deep blue and very windy.

Dwarf Planets

Not-quite-planets, like Pluto.

Ceres

Dwarf planet in the asteroid belt.

Pluto

Used to be the ninth planet, now a dwarf planet.

Asteroids

Rocky things between Mars and Jupiter.

Comets

Icy, dusty things that get tails when near the Sun.

Meteoroids

Small rocks in space that can become meteors.

Sunspots

Cool, dark spots on the Sun.

Solar Flares

Big bursts of energy from the Sun.

Solar Wind

Stuff coming off the Sun that can hit Earth.

Auroras

Cool lights in the sky caused by solar wind.

Solar Nebula

Cloud of gas and dust that made our solar system.

Planetesimals

Bigger things made from the solar nebula that became planets.

Orbits

Paths planets take around the Sun.

Nuclear Fusion

How the Sun makes energy by turning hydrogen into helium.

Radiative Zone

Layer of the Sun where energy moves out slowly.

Convective Zone

Outer layer of the Sun where hot gas moves around.

Photosphere

The Sun's surface that we can see.

Chromosphere

Layer above the Sun's surface.

Corona

Outermost layer of the Sun, seen during eclipses.

Great Red Spot

Big storm on Jupiter that's been there for a long time.

Greenhouse Effect

When gases trap heat in a planet's air.

Asteroid Belt

Area between Mars and Jupiter where most asteroids are.

Meteors

Bright streaks when meteoroids burn up in our air.

Meteorites

Meteoroids that land on Earth.

Exoplanets

Planets outside our solar system.

Gravity

Force that pulls things together, keeping planets around the Sun.

Light-year

How far light travels in a year.

Satellite

Something that goes around a planet.

Radiation

Energy moving in waves, like light.

Tidal Forces

Forces that stretch and squeeze planets.

Astrobiology

Looking for life in the universe.

Lunar Eclipse

When Earth blocks the Sun's light from the Moon.

Solar Eclipse

When the Moon blocks the Sun's light from Earth.

Redshift

Light from far galaxies looks redder because they're moving away.

Hertzsprung-Russell Diagram

Chart that shows how bright stars are compared to their color.

Supernova

Big explosion when a star dies.

Black Hole

Place where gravity is so strong nothing can escape, not even light.

Milky Way Galaxy

The galaxy we live in.

The Big Bang

Idea that the universe started from a tiny point and has been growing ever since.

Matter

Stuff that has weight and takes up space.

Dark Matter

Matter we can't see that pulls on things with gravity.

Dark Energy

Force that's making the universe grow faster.

Constellations

Groups of stars that make pictures.

Light Pollution

Too much light at night that makes it hard to see stars.

Space-Time

Space and time linked together.