Astronomy Flashcards
Day
24 hours for one rotation of earth
Month
29.5 days it takes for moon to wax and wane from a full moon to a new moon and back again
Year
365.25 days for earth to orbit sun
Circuit of milky Way
250 mill years
How was the moon created
Impact on earth, mantle from earth and impact or flew out and made moon
Moon cycle
Full, waning gibbous, first quarter, waxing crescent, new moon, waning crescent, last quarter, waning gibbous
Steady state theory
Universe has always existed and always will, has no beginning or end, matter is constantly being created and the universe is constantly expanding
Big Bang theory
Galaxies are moving away from each other, further away galaxies and moving faster, space itself is expanding, the universe started will all matter in one spot
Continuous spectrum
When you pass white light through a prisim. Has all the colours
White light
All visible colours on em spectrum
Emission lines
When atoms are excited with heat or electricity and give off light of specific wavelengths or colours, which can identify the element.
Emission spectrum
A line spectrum that contains emission lines. Unique to each element.
Absorption lines
When white light is passed through a gas, the gas absorbs the same wavelength it would give off. A wavelength is missing where the light has been absorbed, seen as black lines.
Purpose of absorption lines
Identifies which elements are present in space
Fraunhofer lines
Absorption lines
