By the beginning of the Late Hesperian the atmosphere had probably thinned to its present density.

There are suspicions that as the atmosphere thins, the winds will accelerate to a couple hundred miles per hour.

The atmosphere thinned marginally as the cruiser neared the planet's surface.

Auroral displays occur between altitudes of 60 and 600 miles, where Earth's atmosphere thins.

Soon the atmosphere outside their craft thinned away.

As the atmosphere thinned, the orbit's lift wrapped the occupants in sealed air.

The thin atmosphere, hardly there at all, thinned away entirely to leave the view beautifully black again.

As the oceans evaporated and the atmosphere thinned, the planet devolved into partial barbarism.

The atmosphere within the ships thinned, causing the Monsters to gasp for oxygen.

As the yacht rose and the atmosphere thinned, their twinkling ceased.