Earth and space Flashcards
Astronomy
The study of space
Big Bang
An idea that scientists used to explain how our universe was made, it started off as a mass that was hot and dense and then exploded
Galaxy
A galaxy is a large group of stars, dust ,dark matter and gas held together by gravity
Antimatter
The mirror image of matter every particle of matter has a corresponding particle of antimatter
Hypothesis
Collection of ideas that seem to explain what is observed (predictions that can be tested)
Models
Describes reality based on hypothesis that have withstood observational and experimental tests
Theory
Series of well tested hypotheses that together form a self-consistent and accurate description of nature
Laws
Proven theories that have stood the test of time and have broad applicability
Constellations
Are grouped forming images in the sky there are 88 of the covering the entire sky
Ecliptic plane
Plane of orbit around the sun (not exact circle)
Asteroid meaning
Asteroids are minor planets, especially of the inner Solar System. Larger asteroids have also been called planetoids.Asteroids are lumps of rock that orbit the sun. They are too small too be classified to be planets.Thought to be left over from the time of the formation of the universe.The asteroid belt lies between the orbits mars and Jupiter
Geocentric
having or representing the earth as the centre, as in former astronomical systems
Heliocentric
measured from or considered in relation to the centre of the sun
Universe
The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy
Solar system
The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly
Celestial body
By definition a celestial body is any natural body outside of the Earth’s atmosphere. Easy examples are the Moon, Sun, and the other planets of our solar system
Planet
a celestial body moving in an elliptical orbit round a star
Moon
the natural satellite of the earth, visible (chiefly at night) by reflected light from the sun.
Star
a fixed luminous point in the night sky which is a large, remote incandescent body like the sun
Sun
the star round which the earth orbits
Light-year
a unit of astronomical distance equivalent to the distance that light travels in one year
Asteroid
a small rocky body orbiting the sun. Large numbers of these, ranging enormously in size, are found between the orbits of Mars and Jupiter, though some have more eccentric orbits.
Comet
a celestial object consisting of a nucleus of ice and dust and, when near the sun, a ‘tail’ of gas and dust particles pointing away from the sun
Terrestrial planets
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals
