Space Physics Details/Definitions Flashcards
The Earth orbits the Sun once in…
approximately 365 days
Nature of the rotation of the earth
-Rotates on its axis(which is tilted)
-Complete rotation takes approximately 24 hours
Impact of rotation of the Earth on day and night cycles
-In areas where the sun is not facing that side of the Earth, it would be nighttime.
-In areas where the sun is facing that side of the Earth, it would be daytime.
Why day and night are not of equal length(in most places in the world)
The axis of the Earth is tilted
Why the nature of seasons is periodic
Because of the tilt in the Earth’s axis(different parts of the planet are tilted further or closer away from the sun)
Time it takes for the moon to orbit the Earth
Approximately one month
Why the moon has phases
-As the Moon orbits around the earth, different parts of it are illuminated by the Sun
-As the same side of the Moon always points toward Earth, some of the illuminated part faces away from us
Structure of the Solar System
-The Sun(the only star)
-The eight named planets
-Minor planets(eg. dwarf planets like Pluto and asteroids in the asteroid belt)
-Moons that orbit the planets
-Smaller solar system bodies(eg. comets and natural satellites)
The orbits that planets, minor planets and comets have are…
elliptical(oval-shaped)
The Sun is only at the centre of the orbit when…
the orbit is approximately circular
The planets(in order from the sun)
-Mercury
-Venus
-Earth
-Mars
-Jupiter
-Saturn
-Uranus
-Neptune
The four planets nearest to the Sun are…
rocky and small(compared to those furthest from the Sun)
The four planets furthest from the Sun are…
gaseous and large
At the surface of a planet, the strength of a gravitational field depends on…
the mass of the planet
the strength of a gravitational field around a planet decreases as…
the distance from the planet increases
Why do planets orbit the Sun
The Sun contains most of the mass of the Solar System