Astronomy Ch.1 Flashcards
Astronomy
The study of the univurse
Year
The time required for the Earth to orbit once around the sun
Month
A division of the year that is based on the orbit of the moon around the Earth
Day
The time required for Earth to rotate once on its axis
telescope
an instrument that collects electromagnetic radiation from the sky and concentrates it for better observations
refracting telescope
a telescope that uses a set of lenses to gather and focus light from distant objects
reflecting telescope
a telescope that uses curved mirror to gather and focus light from distant objects
electromagnetic spectrum
all of the frequencies or wavelengths of electromagnetic radiation
constellation
a region of the sky that contains a recognizable star pattern and that is used to describe the location of objects in space
zenith
the point in the sky directly above an observer on Earth
altitude
the angle between an object in the sky and the horizon
horizon
the line where the sky and Earth appear to meet
light-year
the distance that light travels in one year; about 9.46 trillion kilometers
