EARTH SCIENCE (2010) - Astronomy Vocabulary

absolute magnitude

the actual brightness of a star

another name for inner planets

terrestrial planets

Apollo 11

first manned mission to land on the moon

apparent magnitude

the brightness of a star as seen from Earth

asteroid

a small rocky body orbiting the sun, mainly located between Mars and Jupiter

astronomy

the study of the material universe beyond Earth's atmosphere.

basic types of galaxies

spiral, elliptical, irregular

Big Bang Theory

The theory that the universe originated in a huge explosion that released all matter and energy

black hole

final stage in the evolution of a very massive star, where the core's mass collapses to a point that its gravity is so strong that not even light can escape

blue shift

shift toward shorter wavelengths showing an on object is moving TOWARD Earth; very few objects are this type of shift

characteristics of inner planets

- closer together

- terrestrial, rocky

- high density

- small diameters

- shorter revolution

characteristics of outer planets

- further apart

- gaseous

- large diameters

- long revolution

- many moons

- rings

comet

a "dirty snowball" that orbits the sun; the tail points away from the sun due to solar wind

fusion

the act of coming together; combining two atoms

how the sun emits energy

galaxy

a huge group of millions of stars, star systems, star clusters, dust, and gas bound together by gravity

inner planets

Mercury, Venus, Earth, Mars

light year (LY)

the distance light travels in one year, commonly used measurement for distance in space

lunar eclipse

the blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon

a tide just after the first or third quarters of the moon when there is the least difference between high and low water

nebula

a large cloud of dust and gas in space

first step in the life cycle of a star

order of planets from the sun

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

(My Very Educated Mother Just Served Us Nachos)

other names for "outer planets"

Jovian planets

Gas giants

outer planets

Jupiter, Saturn, Uranus, Neptune

our solar system is located in what galaxy?

Milky Way

revolution

the movement of an object around another object

One complete orbit around the sun (a year)

Moon revolves around the Earth

The Earth (and other planets) revolve around the sun in the same direction

rotation

the spinning motion of a planet on its axis

causes day and night, and the appearance of the changing position of stars in the night sky

solar eclipse

Occurs when the Moon passes directly between the Sun and Earth and casts a shadow over part of Earth

seasons are caused by...

the tilt of the Earth's axis

Winter: hemisphere is tilted away from sun

Summer: hemisphere is titled towards sun

solar system

sun, planets, and all the other objects that revolve around the sun

a tide just after a new or full moon, when there is the greatest difference between high and low water

first man-made object to orbit Earth

Sputnik

star

large ball of gas (mainly hydrogen and helium) held together by gravity

tides

rise and fall of ocean water caused by the gravitational pull of the moon and to a lesser degree the sun

considered Earth's twin because of similar mass and diameter

Venus

has a hurricane large enough to fit Earth inside

shortest rotation (day)

unique characteristics of Jupiter

where is the asteroid belt located?

between Mars and Jupiter

What shape is the Milky Way Galaxy?

spiral

life cycle of a star

evidence for expanding universe

1) doppler effect (red and blue shifts)

2) background radiation

red shift

a shift toward longer wavelengths showing an object is moving AWAY from Earth

(think about tail lights on a car: the car in front of us is moving away from us... the tail lights are this color)