Space Exploration and Cosmology Flashcards
What is a planet?
A planet is an object that orbits a sun that has sufficient mass to form a spherical shape
What is a dwarf planet?
A dwarf planet is an object that is too small to be spherical when orbiting a sun, it may also have a very elliptical orbit.
What is a moon?
A natural object that orbits a planet
What is an asteroid?
A small rocky body that orbits the sun
What is the solar system?
The solar system is the sun and all its satellite planets, their moons and the asteroid belt.
What is a star?
A star is an object in space that is massive enough to undergo nuclear fusion, producing and emitting electromagnetic radiation
What is an exoplanet?
A planet that has been discovered to exist outside our own solar system.
What is a galaxy?
A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction
What is the universe?
All existing matter and space considered as a whole
How high are satellites in low earth orbits?
Around 160 km to 2000 km above the surface of the earth
How long does it take a satellite to go orbit the earth in a low earth orbit?
90 minutes
What type of orbits are low earth orbits?
polar orbits and low inclination orbits
What are satellites in low earth orbits good for?
Because of their short orbit time of 90 minutes they are good for..
monitoring weather, global positioning system (gps), communications, environmental monitoring and scientific research
How high above the surface of the earth is the Hubble Bubble Space telescope?
600 km
How high above the surface of the earth is the International Space Station?
400 km
What determines the orbital period of a satellite?
The closer the satellite is to the surface of the earth the shorter its orbital period.
(This also works for planet in relation to the sun. The closer a planet is to the surface of the sun, the shorter its orbital period.
How high are satellites in geostationary orbits?
Approximately 36,000 km above the surface of the earth
How long does it take a satellite to go orbit the earth in a geostationary orbit?
24 hours
What are satellites in geostationary orbits good for?
TV stations and communications
