NASA @NASA
We know the size, shape and rotation rate of Earth because of a field of science known as geodesy. š Geodesy lets us use GPS, plan rocket launches and measure tides. Today we're improving these measurements down to the millimeter. Check it out: https://t.co/PdaEJzsGYk https://t.co/JOsOcqlfZ8 — PolitiTweet.org