Space Physics Flashcards
How long does it take the Earth to rotate fully on its axis?
24 hours
What causes the apparant daily motion of the sun and the periodic cycle of day and night?
Due to the Earth’s rotation around its axis
How long does it take the Earth to orbit the sun
Approx 365 days
What causes the different seasons?
The combination of the orbiting of the Earth around the Sun and the Earth’s tilt
How long does it take the moon to orbit the Earth?
Approx one month
What causes the periodic nature of the Moon’s cycle?
The relative positions of our Sun, Earth, and Moon.
- the moon orbits earth and earth orbits the sun
average orbital speed equation
v = (2 x pi x r)/T
Describe the Solar System
Contains:
a) one star, the Sun
b) the eight named planets
c) minor planets that orbit the sun (like pluto and asteriods)
d) moons, that orbit the planets
e) smaller Solar system bodies (comets and natural satellites)
The eight planets in order of closest to the sun
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune
The four planets near to the sun are
rocky and small
(mercury, venus, earth and mars)
the four planets furthest from the Sun are
gaseous and large
(jupiter, saturn, uranus, neptune)
accretion process
- dust left over after the sun formed contained many heavy elements formed in a supernova explosion
- first the dust made a disc which rotated around the sun due to gravity
- slowly the dust started to clump together due to gravitational attraction between the particles
- the inner planets are rocky because the temperature near the sun meant that only elements with high melting points existed as solids
satellite
an object that orbits a larger object
natural satellites
Asteroids, comets, moons
Elliptical orbit
An orbit that has an oval shaped path (like an elongated circle). Due to the gravitational interactions amoung the sun, planets and other celestial bodies.
where is the sun in the elliptical orbits
at one focus of the orbital ellipse (not the center)
The strength of the gravitational field at the surface of a planet depends on…
the mass of the planet
The strength of the gravitational field around a planet decreases as..
the distance from the planet increases
The speed of light
3 x 10^8
equation for calculating time with speed of light
time = distance/speed
Why do planets orbit the Sun?
Because the Sun contains most of the mass of the Solar System
What keeps the object in orbit around the Sun?
The gravitational attraction of the Sun
What affects the strength of the Sun gravitational field?
Decreases when the orbital speed decreases as the distance from the Sun increases
Why does an object in ellipitcal orbit travel faster when closer to the Sun?
The closer, the stronger the gravitational pull
