Planet Earth And Beyond Flashcards
what is the sun?
- the sun is our most important star
- centre of solar system
- body of hot glowing gas
- produces energy
what does the solar system consist of?
- sun
- planets
- other bodies that move around in space
what is a planet?
rounded body traveling around a star in a clear circular path.
name three conditions to determine wether object is a planet?
- travel around a star
- be almost spherical in shape
- be able to keep its orbital path clear of other objects
name the eight planets that orbit the sun
mercury
venus
earth
mars
jupiter
saturn
uranus
neptune
name the two groups planets can be classified in
1.inner rocky planets
mecury, venus, earth, mars
2.outer gas giants
jupiter, saturn, uranus, neptune
what is a dwarf planet?
a planet that is not able to keep its path clear of other objects
what is a moon?
a body that revolves around a planet
doen’t have own light source - reflect light from sun
each planet has own moon or moons except mecury + venus
what is an asteroid?
asteroids are too small to be planets
made of similar material to terrestrial planets
iron cores
what is a meteoroid?
small pieces of rock in space smaller than asteroids
what is a meteor?
a meteoroid when it enters earths atmosphere, it burns when it falls
what are meteorites?
remains of the meteoroid after it crashes on the earth’s surface
what are comets?
bodies made up of gas and frozen rock
where is earth’s position?
third planet from the sun and only planet to support life as we know it
name conditions that allow life to happen on earth
temperature: ideal distance from sun
water: in 3 phases or states, solid liquid and gas. essential for life
light: needed by plants for photosynthesis and by all living organisms for food and energy
oxygen: a gas essential for life (21 % air)
what is a galaxy?
a group of stars held together by their mutual gravity
what is the milky way?
the galaxy in which our solar system is found
what is a black hole?
infinite mass of nothingness with poweful gravity
able to suck up everything in its path
what is the position of the sun in the milky way galaxy?
the milky way galaxy consists of a thick bulge in the middle with 4 spiral arms
our sun is located in one of the spiral arms
what is our nearest star
nearest star to earth = sun
nearest star to solar system = Alpha centauri
what is a light year?
distance light travels in one year
what is a telescope?
an instrument used for looking into space
it produces a magnified image of an object or body in space to make it seem closer and look bigger
what is an optical telescope?
a telescope which recieves light from distant objects in space
name 3 conditions for telescopes to work well
little or no light nearby
climate with mainly clear skies at night
clean air with little or no pollution for better visibility
high altitude
what is the HST?
the hubble space telescope
orbits earth approximateley 110 km from earth’s surface
designed to be repaired by astronauts
unclear images until refocused by scientists
what is the SALT?
southern african large telescope
redesigned optical system
larger field view effective collecting area
wheighs 82 tons
what is a radio telescope?
a telescope that recieves radiowaves from the universe
look like satellite dishes
very big
what is SKA?
Square Kilometre Array telescope
telescope can recieve radiation from space
large
big project held by 16 countries
