In addition to browsing the Earth, Google Earth allows you to view heavenly objects, including stars, constellations, galaxies, planets such as Mars and the Earth's moon. To view these objects, click View > Switch to Sky or click . and choose Sky. In Sky, the Earth is hidden and the 3D viewer presents a view of the sky.
Note - When you use Sky, the view is above your current location on Earth. For example, if you go to Paris and open Sky, you will see what is in the sky above Paris at the current time. When you exit Sky, you return to this same location.