Match the words at the left to the correct blanks in the sentences at right.
A camera is an example of an instrument used for IMAGING observations.

SPECTROSCOPY refers to telescopic observations in which we separate an object's light so we can measure its intensity at different wavelengths.

If we want to confirm that a star's brightness alternately dims and brightens, we need TIME MONITORING observations of the star.

The familiar twinkling of the stars is caused by ATMOSPHERIC TURBULENCE, which also blurs telescopic images.

Human civilization is responsible for what astronomers call LIGHT POLLUTION.