Astronomy Fact
Its estimated that the number of stars in the universe is greater than the number of grains of sand on all the beaches in the world! On a clear night, we can see the equivalent of a handful of sand.

Notes about viewing ESVs:
When using lookangles, choose passes with high magnitudes; less than 6.0. ("Looks" are local time.)
Best viewing is when ESV is in Earth's penumbra; on the map, it's the solid line during night.
Dotted line on map denotes ESV is dark, in Earth's umbra (shadow).
Objects in orbit have to maintain a speed of at least 17,500mph, therefore ESVs traverse the sky noticeably different than aircraft.
ESVs appearing to blink are either tumbling rocket bodies, or spinning payloads with deployed solar arrays.
High-Eccentricity objects have a more ellongated orbit. Ground trace looks like a backwards C.
Regression-Ground traces will move West with each orbit due to Earth's rotation.