The exosphere is the high-altitude region where atmospheric density is sparse and Jeans escape occurs.

For several years, he and colleagues led further expeditions studying the geology, agriculture, social and family life and monastic practices in this remote, high-altitude region.

Unless you live in a high-altitude region where the air is drier and requires longer cooking times, following the recipe instructions should yield a mouthwatering pan of snickerdoodles.

Despite the stunted height of the trees in this high-altitude region, silky sifakas can occasionally be spotted from the bungalows.

The 145-year-old fossils, which were found in western America, reveal that the herd had been drinking water from high-altitude regions as well as the low-lying desert.

But these high-altitude regions were covered with snow throughout winter, and the inhabitants used to migrate to lower altitudes for six months.

Winter travel is close to impossible in many of the more remote and high-altitude regions.

Birds breeding in southern or high-altitude regions move northwards or towards the lowlands in winter.

The ecoregion includes the high-altitude regions of Corsica's mountain ranges.

It is not generally found in high-altitude regions.