Astronomy exam review SNC1W1

star

Massive collections of hot gases that radiate large amounts of energy.

planet

A large celestial object that travels around a star.

satellite

A celestial object that travels around a planet or dwarf planet in a closed path.

galaxy

Huge collections of stars, gas, dust, and planets.

astronomy

The scientific study of celestial objects beyond Earth.

dwarf planet

Celestial objects that orbit around a star and have enough mass to be pulled into a stable sphere shape by gravity but do not dominate their orbit.

asteroid

Small celestial objects made of rock and metal.

meteoroid

Chunks of rock and metal that are smaller than asteroids.

comet

Large chunks of ice, dust, and rock that orbit the Sun.

solar eclipse

When the Moon is aligned between Earth and the Sun, it blocks the Sun from being observed from Earth.

lunar eclipse

When Earth is positioned between the Sun and the Moon, casting a shadow on the Moon.

constellation

Regions of the sky where stars can appear as a pattern.

Small to Medium Star (< 5 solar masses) life cycle

Red giant, white dwarf, black dwarf

Large Stars (10 to 30 solar masses) life cycle

Red super giant, supernova, neutron star

Extremely Large Star (> 30 solar masses) life cycle

Red supergiant, supergiant, black hole

Hertzsprung-Russell diagram

A) The Sun D) Blue Supergiants G) Oldest Stars

B) Red Supergiants E) White Dwarfs H) Youngest Stars

C) Red Giants F) Red Dwarfs

ways in which early people used astronomy in their daily lives

• Planting and harvesting crops

• Navigation

• Religious/Cultural significance

Planting and harvesting crops

Stars exhibit patterns marked by the changing of the seasons.

Navigation

People living in areas surrounded by water had no land to use as a reference point, and often used stars for navigation.

Inner planets

• Rocky surfaces

• small in size

• few to no moons.

Outer planets

• Large in size

• many moons

• composed mostly of gases (and some liquids); no solid surface.

Retrograde motion

Certain planets farther from the Sun than Earth exhibit a reversal of direction in their apparent path across the sky due to Earth passing them in its orbit, creating an optical illusion.

Dark Side of the Moon

The side of the Moon that we don't see from Earth, which is not actually dark but remains hidden due to the Moon's synchronous rotation and revolution.

Importance of the Sun for life on Earth

• Light, necessary for plants to perform photosynthesis.

  Without plants, animals could not exist.

• Heat, the Earth would be far too cold for any life to exist, even bacteria.

Reaction to a total eclipse of the Sun

People centuries ago would have reacted in fear or panic due to a lack of scientific knowledge, possibly believing the world was ending or that God was angry.