Celestial Bodies Flashcards
Celestial bodies
General name for an object in space
Meteor
Solid object from outer space that enters the earths atmosphere
Asteroid
Rocky celestial object greater than 1m, smaller than a planet and orbits the sun.
Comet
Ball of frozen gas, ice, rock and dust with a highly elliptical orbit.
highly elliptical- orbit looks more like an oval than a circle
Planet
any object that orbits a star, is large enough to form a rough sphere under its own gravity and has cleared its orbit
terrestrial planets eg
mercury, venus earth mars
jovian planets eg
jupiter saturn uranus neptune
Terrestrial planets
or rocky planet, is a planet that is composed primarily of silicate rocks or metals.
Jovian planets
a gas/ice giant, means they are like Jupiter
moon
Any natural satellite of any planet
star
A ball of gas that emits light and heat due to nuclear explosions in its core
Dwarf planets
Small planets that dont quite meet the def. of a planet
lack the gravitational forces needed to clear the material found in their orbits.
Exoplanets
planets orbiting a star other than our own
What is a black hole
star with a strong force of gravity that light cant escape from it.
Solar system
star and all the objects that orbit
Geocentric model
Earth was the centre of the universe and everything orbited around it (Aristotle)
Heliocentric model
the sun was the centre, celestial bodies moved around the sun in fixed orbits (Copernicus)
Law of Planetary Motion
A planets orbit has an ellipse shape that travels around the sun
The Big Bang Theoiry
The universe is expanding, all objects are moving away from each other (singularity)
the concept that the universe began as a single point (singularity) and kept expanding, with all objects moving away from each other
Galaxy
huge collection of gas, dust and billions of stars and the solar systems held together by gravity
Two main types of telescope?
radio and optical
What did Hubble and milton Humason discover
The Big Bang Theroy
Singularity
our universe emerged from a singularity — a point of infinite density and gravity
Gravity
A force that attracts objects to each other
Calculate weight (N)
Weight (N) = Mass (Kg) x Gravity (m/s^2)
What are the key pieces of evidence that support the Big Bang Theory?
-Scientists have proven that the earth is constantly expanding
-The universe was formed from a singularity (idk)
-Cosmic Microwave Background Radiation (CMBR): the energy leftover from the original explosion.
