Space

What is astronomy?

The study of what is in space

what are constellations?

patterns of stars in the sky

what are moons?

objects that revolve around a planet

What are comets?

a frozen core of ice, gas and dust. They orbit around the sun in an elliptical way. When they get close, they heat up and release gas

what are meteors?

matter from space (shooting star), that burns when it enters the earth’s atmosphere.

what are asteroids?

a small rocky body that orbits the sun

What are the two types of planets?

• Terrestrial (inner), Jovian (outter)outer

What’s the “perfect” planet?

Earth

3 characteristics of earth as to why it can support life

1. perfect distance from the sun - not too hot/ cold

2. magnetosphere protects us from solar wind

3. our atmosphere allows for a steady temp

What’s the geocentric model?

the first model of our solar system was earth centered (stars and planets revolve around the earth)

What’s the planetary motion?

Process of how planets orbit around the sun. The sun’s strong gravity pulls the planets towards it.

What’s the retrogarde motion?

planets (mars, jupiter and saturn) look like they’re moving backwards in the sky.

What do plaents revolve around?

The sun

What’s the structure of the universe?

Stars → Star Clusters (group of stars that travel together) → Galaxies (billions of stars)→ Universe (billions of galaxies)

What’s the doppler effect?

increase or decrease in the frequency of waves as a way to tell whether stars are moving away or towards you. star close = seems bluer. star far = redder

What’s the universe?

Everything that exists

Groups of stars that seem to form shapes or figures are called:

Constellations

We see planets because they ____

reflect light from the sun

Huge collections pf gas, dust, billions of stars, planets and other celestial objects (things in space)

Galaxies

A celestial object that is rocky and makes contact with the earth’s surface is called a _____

Meteorite

How do we know our universe is expanding?

The stars are shifting towards the red part of the spectrum

When can we see a comet’s tail?

Only when the comet path is close to the sun (due to the sun’s heat, Ice and dust turn to gas. Solar wind pushes the gas and dust away, creating a visible tail).

What’s the hottest planet in our system?

Venus

What galaxy is the sun in?

The milky way

What type of galaxy is the milky way?

Spiral

Where does the energy from the sun come from

A nuclear fusion in the sun’s core. 1) four Hydrogen atoms fuse. 2) a single Helium is created. 3) Leftover mass is converted to energy

Is earth bigger than the sun?

No

Size, brightness and temperature of red stars

Small, dim and cold

Size, brightness and temperature of blue stars

Big, Bright and hot

(T/F) Most stars (95%) are low mass, like our sun

true

(T/F) our sun will eventually become a black hole

false

(T/F) the moon is a non-luminous object (explain)

True, it does not produce its own light, it reflects sunlight

What’s the solar nebula theory?

A nebula (spinning cloud of gas and dust) gets clumped together by gravity to form stars and planets

What are the terrestrial planets?

mercury, venus, earth and mars

What are the jovian planets?

jupiter, saturn, uranus and neptune

order of planets closest to furthest from the sun

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

What does the term “light year” mean?

The distance light travels in one year

What does the term “astronomical unit (AU)” mean?

Distance from the earth to the sun

What’s the Big Bang theory

Explanation of how our universe started about 14 billion years ago from a very hot, dense point and how our universe is still expanding

What evidence supports the Big bang theory

Galaxies are moving away (redshift)

3 key differences between the inner and outer planets

1. Composition. Inner= rocky, solid surfaces. Outer= gas giants, mostly gas and ice

2. Size. Inner= small. Outer= big

3. Distance from the sun

4 properties of stars we observe

brightness, color, size, temperature

What are satellites?

objects that revolve around planets. ex:moon

what are the 2 planets that don’t have moons?

Mercury and venus

why do we see different phases of the moon?

Because the moon orbits earth and reflects sunlight. As it orbits the earth, different amounts of sunlight is reflected.

When does the size of the moon change?

the size of the moon never changes, only the lit part we see changes

Difference between solar eclipse and lunar eclipse

Solar eclipse: during daytime. the moon is between earth and the sun.

Lunar eclipse: during nighttime. Earth is between themoon and the sun.

What’s solar eclipse?

When the moon is between the sun and earth, blocking the sunlight

What’s lunar eclipse?

When the earth is between the moon and sun, blocking the sunlight from hitting the moon (causes a red moon)

Difference between a meteor and a meteorite?

Meteor= streak of light in the sky (burns up before touching the ground

Meteorite= the rock that falls from space and reaches ground