- the height or vertical distance of an object above a given point (such as Earth's surface)
artificial
- made by people; not occurring naturally
asteroid
- a rocky object in space, usually found in a belt between Mars and Jupiter
atmosphere
- The layers of gases surrounding the earth
B
barriers
- obstacles that prevent movement
C
climate change
- A change in the average conditions, such as temperature and rainfall, of the Earth over a longer period of time. Scientists have observed that Earth's surface is warming over the last 20 years.
comet
- a frozen mass of gas, dust, and ice that revolves around the Sun in predictable orbit
complex
- complicated, having many parts
D
distress beacon
- a tracking device used to send signals about the location of ships, aircraft, or people in need of emergency help
drag
- A force acting on a body to slow down its movement
E
equator
- an imaginary circle around the earth
F
first responders
- People who respond quickly to emergency situations, such as paramedics, police officers, firefighters, and rescue workers
G
geostationary
- Referring to a spacecraft that travels in orbit above the earth's equator at a speed matching the earth's rotation, so that it always stays above the same place on the Earth's surface and, when observed from the earth's surface, appears to be standing still
gravity
- a force that pulls objects with mass together. Gravity pulls objects down toward the center of the Earth
N
natural satellite
- a body in space, not made by man, that orbits around a larger body, such as moons that orbit planets
O
obsolete
- no longer in use
orbit
- Noun: the path an object follows as it goes around another object in space Verb: to travel around an object in space
orbital period
- The time required for a satellite to complete one full orbit. For Earth, its orbital period is one year.
orbital velocity
- The speed necessary for a satellite to remain in orbit
P
poles
- The northern and southern ends of the Earth's axis, an imaginary line through the center of the earth around which the planet rotates, usually referred to as the North Pole and the South Pole.
R
remote
- distant, far removed
rotation period
- The time required for an object to make one complete turn on its axis. For Earth, its rotation period is 24 hours.
S
solar panels
- devices on satellites that convert light from the sun into energy to power the satellite
Space Age
- A period of Earth-based space exploration and space technology, considered to have begun with Sputnik 1 in 1957 and continuing to the present day
T
telescope
- An instrument for viewing distant objects that can make faraway things appear closer
transmission
- the passage of signals between sending and receiving stations
