How far is it to the sky?

This question is debatable since the atmosphere continues, in some form of density, to the outer corners of space. However, this source seemed to best explain the distance from the ground to the various layers of the atmosphere.

Distance from the ground

0-10 km to the troposhere

10-50 km is the stratosphere
50-87 km is the mesosphere
87-500 km is the thermosphere
500-520km++ exosphere

Layers of the Earth's atmosphere:
The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space. 1) The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer.
2) Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun.
3) Meteors or rock fragments burn up in the mesosphere.
4) The thermosphere is a layer with auroras. It is also where the space shuttle orbits.
5) The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.

The source of this material is Windows to the Universe, at http://www.windows.ucar.edu/ at the University Corporation for Atmospheric Research (UCAR). © The Regents of the University of Michigan. Windows to the Universe® is a registered trademark of UCAR.