astronomy test Flashcards
how were Moon’s Maria formed?
Lava cooled and then turned black
why is a rising moon sometimes reddish?
light waves have to travel through more atmosphere and blue wavelengths are almost completely scattered and don’t reach observers on earth
why does the rising moon look so large sometimes?
optical illusion and moon has an elliptical orbit to Earth
who was ptolemy?
mathematician who created geocentric model that had epicycles for planets that backtracked
who was Copernicus?
created heliocentric model. all planets including earth orbit Sun
what did Galileo do to support copernicus
he observed Jupiter’s moons and found that other objects don’t just orbit Earth
what is Keplers first law?
law of ellipses. planets orbit sun in an ellipse
what is Keplers second law?
law of equal area. planets orbit faster when closer to the sun
what is keplers third law?
d^3/p^2=1
what is newtons law of universal gravitation?
forces on earth also work in the heavens, explained planets go around the sun because of gravitational force
what were two questions newton couldn’t answer?
how does gravity work? why doesn’t gravity cause the universe to collapse?
