The Moon is Earth’s only natural satellite—a rocky, cratered body about one‑quarter the diameter of Earth, orbiting at an average distance of approximately 384,400 km. It influences tides, stabilizes Earth’s axial tilt, and was formed about 4.5 billion years ago following a collision between Earth and a Mars-sized object.
Source: science.nasa.gov
19/06/2017
Where will you be during the Eclipse across America? On August 21, the shadow of the Moon will cross the continental USA for the first time since 1979. The predicted path -- a certainty given modern astronomical knowledge -- is shown in the featured NASA video. Most people in the USA will be within a day's drive to the path of the total solar eclipse, while the rest of North America will see a partial solar eclipse. In the path of totality, given clear-enough skies, the Moon will block out the Sun making it eerily dark for as long as 2 minutes and 40 seconds. If interested in attending an eclipse party, please contact your local amateur astronomical society, science center, park, or university to see if one is already being planning. Some eclipse chasers have traveled to the end of the world to see a total eclipse of the Sun, and along the way have recorded many entertaining adventure stories.