๐๐๐ข๐๐ง๐๐ ๐ Flashcards
Explain what a star is made up of
A star is a large ball of gas that gives off light and heat
What is a galaxy?
A galaxy is a large groups of stars, dust, gas and dark matter held together by gravity
what is astronomy
the branch of science which deals with celestial objects, space, and the physical universe as a whole
what are celestial bodies
Celestial bodies are any natural objects found outside of the earths atmosphere these include planets, stars, moons, comets and asteroids.
In 350BCE Plato and Aristotle had what idea
The geometric model: The sun, moon, plants and stars all orbit around the earth, which does not move
in 150CE Ptolemy had what idea
Agreed with the geocentric model. His calculations could be used to predict planetary movements
In 1609CE galileo had what idea
Agreed with the heliocentric model, invented the telescope and observed the orbit of Venus, drew the phases of the moon
In 1687 Newton had what idea
Discovered gravity which helped to prove our understanding of the Solar System
Terrestria Planets
Mercury
Earth
Venus
Mars
Jovian planets
Jupiter
Saturn
Uranus
Neptune
what planet has the longest day
venus- 243 days to spin on its own axis
What planet takes the longest to orbit the sun (Year)
jupiter- 12 years
What planet has the shortest orbit around the sun
mercury - 88 days
Explain what a star is
a fixed luminous point in the night sky which is a large, remote incandescent body like the sun
explain what a planet is
a celestial body moving in an elliptical orbit around a star
explain what a moon is
the natural satellite of the earth, visible by reflected light from the sun
explain what an asteroid is
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
Explain what a comet is
A celestial body consisting of a nucleus of ice and dust and, when near the sun, a โtailโ of gas and dust particles pointing away from the sun
Explain what a universe is
All the stars and galaxies that exist
How does a star make its own light and heat?
Nuclear reactions occur between two hydrogen atoms.
The nucleus of one hydrogen atom fuse with the nucleus of another hydrogen atom, forming a completely new element called helium.
The 3 rules for a celestial object to be a registered as a planet
- The object must orbit a sun.
- The object must be big enough to allow its own gravity to pull it inwards to make it look rounded.
- Planets clear their orbit when there are no more objects to crash into.
how do planets orbit the sun
- The Sun is a very large object and has a very large gravity.
- The Sunโs large gravity โpullsโ the planets towards it.
- At the same time the planets own gravity tries to pull away from the sunโs gravity.
- This produces the orbit of the planet around the Sun.
Name the 2 effects of the earths tilt
1) It changes the length of the day throughout the year
2) It changes the angle at which sunlight hits the ground throughout the year
Name the 8 phases of the moon
New moon
waxing crescent
first quarter
waxing gibbous
full moon
waning gibbous
third quarter
waning crescent
Lunar eclipse (4)
- A lunar eclipse occurs
when the Earth becomes between the Sun and Moon - when the Earth casts a shadow across the entire full moon
- a full moon
- A lunar eclipse happens once or twice a year and last for a few hours