Download Mission 1 Glossary

Mission 1 Glossary
angle
what lies between two rays which share the same endpoint
asteroid
a rocky object in space that can be anywhere from a few feet
wide to several miles wide. Most asteroids in our solar
system are part of a belt between Mars and Jupiter.
atmosphere
the mass of gas surrounding an object in space and held by
the object's gravitational field
axis
an imaginary straight line around which an object spins. The
Earth's axis is tilted 23.45 degrees.
billion
A number represented as a 1 followed by nine zeros
(1,000,000,000). If you have a bucket that holds 10 thousand
marbles, you would need 100 thousand of those same
buckets to hold a billion marbles! That's a lot of marbles!
Celsius
metric temperature scale at which water freezes at 0° and
boils at 100°
crater
a bowl-shaped depression on a surface made by the impact
of a large object, such as a meteor
diameter
a straight line segment which passes through the center of a
circle or sphere with both its ends on the boundary of the
circle
extraterrestrial
originating or occurring outside the Earth and its atmosphere;
when scientists search for extraterrestrial life, they are trying
to find life on someplace other than Earth
Fahrenheit
the temperature scale at which water freezes at 32° and boils
at 212°
freefall
another term for the feeling of "weightlessness"
galaxy
a huge collection of gas, dust, and stars in space. Our own
galaxy is called the Milky Way.
gravity
the natural, invisible force between objects that attracts them
to each other
heat
a form of energy that causes the sensation of feeling hot or
warm
kilometer
A unit of measure for length. One kilometer equals 1,000
meters. A kilometer is also equal to .6214 miles.
light
electromagnetic radiation that has a wavelength that is visible
to the naked eye
light year
the distance that light can travel in one year (9.5 trillion
kilometers)
Low Earth Orbit
An area that satellites travel in that is about 200-500 miles
(320-800 kilometers) above Earth. Satellites traveling in Low
Earth Orbit have to travel very fast so that gravity does not
pull them back out into the atmosphere.
Luna II
Russian spacecraft, the first spacecraft to land on the Moon.
Humans were not on this spacecraft. It landed on the Moon
on September 14, 1959.
lunar
having to do with the Moon
microgravity
an environment in which there is minimal gravitational force
Moon
can be any natural object orbiting around another; often
refers to the Moon of the Earth (but other planets have
moons too.) The Moon of the Earth was probably formed
when a large object struck the Earth a long time ago.
navigate
to plan, record and control the movement of a ship or plane
Moon - can be any natural object orbiting around another;
often refers to the Moon of the Earth (but other planets have
moons too.) The Moon of the Earth was probably formed
when a large object struck the Earth a long time ago.
Neil Armstrong
American astronaut and the first person to step on the Moon.
When he landed on the Moon, he said, "That's one small step
for man; one giant leap for mankind."
orbit
the path followed by an object in space as it travels around
another object
phase
one of the apparent forms of the Moon. The Moon cycles
through 8 phases.
revolve
to move in an orbit or circle around something
rotate
to move around a center point, or axis, just like how a wheel
rotates
satellite
an object that orbits another in space. The Moon is a natural
satellite of the Earth.
star
an object in space composed of intensely hot gasses that
creates light and heat energy from nuclear reactions going on
inside of it
Sun
a star, and the largest object in our solar system. The Sun is
the closest star to Earth and is about 5 billion years old.
telescope
an instrument used for viewing far away objects, such as
planets and stars
temperature
the degree of hotness or coldness of a body or environment
trillion
A number represented as a 1 followed by twelve zeros
(1,000,000,000,000) If you have a bucket that holds 100
thousand marbles, you would need 10 million of those same
buckets to hold a trillion marbles! That's a lot of marbles!
weightless
not experiencing the effects of gravity