Spacw Flashcards
How much time does it take for the earth to spin on its axis
24 hours - 1 day
How long does it take for the earth to orbit around the sun?
365 days - 1year
How long does it take for the moon to orbit the earth?
Approximately 1 month
What is the equation for average orbital speed?
V = 2nr/ T. Where T is orbital period
What does the solar system contains?
Sun, 8 planets, moons, minor planets, asteroid belt, smaller bodies like comets
What are the names and order of planets from the sun?
Mercury, Venus, earth, Mars, Jupiter, Saturn, Uranus, Neptune
What properties do the first four and last four planets have?
First four - rocky small
Last four - large gaseous
How does strength of gravity change with distance?
Graviatwitonal field at the surface depends on it mass
Strength decreases as the distance from planet increases
What is the speed of light?
3x10^8 m/s
Why do the planets orbit the sun?
The sun contains most of the mass of the solar system
In an elliptical orbit when does an object moved fastest?
An object moves fastest in an elliptical orbit when it is closer to the sun as it needs
In what order are the moons phases?
New moon
Waxing crescent
First quarter moon
Waxing gibbous moon
Full moon
Waning gibbous moon
Last quarter moon
Waning gibbous crescent moon
What is summer solstice
When the northern hemisphere have their longest day and the southern hemisphere their shortest
What is equinox
The time in the year when day and night are approximately equal lentgh
What is winter solstice
When the northern hemisphere have their shortest day and the southern hemisphere their longest
What type of star is our sun and what does it consist of ?
Medium sized safe consisting of mainly hydrogen and helium
What powers stars?
They are powered by nuclear reactions that release energy
What is an asteroid?
Small rocky object that orbits the sun
What is a comet?
Comets are made of ice and dust and orbit the sun elliptically
What is a galaxy?
Galaxies are made of billions of stars
What is the measure of astronomical distances?
A light year
How long is a light year?
9.5 x 10^15m
How is a star formed?
From interstellar clouds of gas and dust that contain hydrogen called a nebula
What comes after a nebula or interstellar cloud and how is it formed?
A protostar is formed as a nebula collapses and increases in temperature due to its internal gravitational attraction
What comes after a protostar and how is it made?
A protostar becomes a stable star when it’s inward gravitational force Balances with its outward force caused by thermal expansion
What happens after a stable star and why?
Eventually it runs out of hydrogen. Helium fusion takes place in the core so it begins to expand into a red giant or red supergiant
What happens after the red giant and why?
A planetary nebula caused by the ejection of a red giants outer layers
This planetary nebula has a hot dense core called a white dwarf
What happens after the red supergiant and why?
Eventually they explode into a supernova which forms a nebula that contains hydrogen and heavier elements. Also it produces wither a neutron star or black hole
What is the Milky Way and how big is it?
One of many billions of galaxies that make up the universe. 100000light years wide
What is redshift?
Redshift is the increase in the observed wavelength of electromagnetic radiation emitted from receding stars and galaxies
What does redshift show?
That the universe is expanding and gives evidence for the Big Bang
What is the name of the microwave radiation at all points in space?
Cosmic microwave background radiation or (CMBR)
What is the equation that comes with bubbles constant?
Ho = v/d
What is hubbles constant?
2.2 x 10^-18 per second
What is hubbles constant in words?
The ratio of the speed at which the galaxy is moving away from the earth to its distance from the earth
What is the equation for the age of the universe?
d/v = 1/Ho
