What does a barometeter do?

Is the exosphere 80-550 kilometers above sea level? Where does the word gibbous comefrom? How might ancient people's have felt about an eclipse of the sun? Which day of the week was on 9th September 1960? What would happen if the Moon's revolution speed were twice as fast as it is now? How long will it take to travel to neptune at light speed? How long does it take to get to callisto? What would happen to your body if you went to the moon? What is the univeres name? What is cause by the Moon's near 28 day? What part of the sun produces the majority of heat and lights? What was the name of the first Russian moon mission? How does waxing crescent appear? Where do most tornadoes move along the front or coast? What element is the sun and many other stars are made mostly of the element? What does STS mean for nasa? Where does the sun rise in the pacific and set in the Atlantic? Which country does not get the sun light? When units are finished in the available phase what phase do they go to next? Where is vv cephei?

What does a barometeter do?