Astronomy
the study of the moon, stars, and other objects in space
Axis
an imaginary line that passes through Earth's center and its North and South Poles
Rotation
the spinning of earth on its axis
Revolution
the movement of an object around another object.
Orbit
the path of an object as it revolves around another object in space
Solstice
The two days of the year on which the noon sun is directly overhead at either 23.5 degrees South or 23.5 degrees North, causing the shortest and longest day of the year
Equinox
The two days of the year on which neither hemisphere is tilted toward or away from the sun and the sun is directly over the equator; period of equal days and nights; the beginning of spring and autumn
Force
a push or a pull
Gravity
a force that attracts all objects toward each other
Law of Universal Gravitation
every object in the universe attracts every other object
Mass
The amount of matter in an object
Weight
the force of gravity on an object
Inertia
the tendency of an object to resist any change in its motion
Phases
the different shapes of the moon you see from Earth
Eclipse
when an object in space comes between the sun and a third object, it casts a shadow on that object,
Solar Eclipse
the blocking of sunlight to Earth that occurs when the moon is directly between the sun and Earth.
Umbra
the very darkest part of the moon's shadow; cone shaped
Penumbra
the larger part of the shadow the moon casts; not as dark as the umbra
Lunar Eclipse
occurs at a full moon when Earth is directly between the moon and the sun; Earth blocks sunlight from reaching the moon
Spring Tide
the gravity of the sun and moon pull in the same direction and with their combined forces, produce a tide with the greatest differences between low and high tides
Neap Tide
a tide with the least difference between low and high tides; occurs twice a month; during the moon's first-quarter and third-quarter phases
Telescope
device built to observe distant objects by making them appear closer
Maria
the moon's dark, flat areas; Latin word for "seas"; made of hardened rock formed from huge lava flows that occured between 3 to 4 billion years ago
Craters
large round pits on the moon's surface
Meteoroids
chunks of rock or dust from space
Rocket propulsion
hot gas being propelled out of the rocket
Satellite
an object that revolves around another object in space
Space Shuttle
a spacecraft that can carry a crew into space, return to Earth, and then be reused for the same purpose
Space Station
a large artificial satellite on which people can live and work for long periods. They are used for research, including medical, geological, and astronomical experiments.
Space Probe
a spacecraft that carries scientific instruments that can collect data, bu has no human crew; gathers data about distant parts of the solar system where humans cannot easily travel
Rover
small robots that move around on the surface that typically collect and analyze soil and rock samples
How is day and night caused?
Earth's rotation on it's axis which takes about 24 hours.
How do we mark one year?
It takes the Earth 365 days to make one complete revolution around the sun.
seasons on Earth
4 are created because Earth's axis is tilted as it revolves around the sun
geosynchronous
A satellite that revolves around Earth at the same rate that Earth rotates is in this type of orbit.
Multistage rockets
Rockets which have a number of fuel containers. After the fuel in a container is used, the container falls off of the rocket. This made it possible to travel into space.
tides
Caused by the force of gravity from the sun and the moon acting on Earth's waters. Most places on Earth have two high and two low every day.