2021-03-22
Château de Joux in the Jura mountains of France (© Ivoha/Alamy)
汝拉山中的Chateau de Joux堡，法国 (© Ivoha/Alamy)
Overlooking the valley linking France to Switzerland (the Cluse de Pontarlier), Joux castle – with its keep, towers, drawbridges, surrounding walls and fort – offers fantastic evidence of the way fortifications have developed over the years. Built in the 11th century, then modified by Vauban in the 17th century, people will discover 10 centuries of history there.
Château de Joux in the Jura mountains of France (© Ivoha/Alamy)
汝拉山中的Chateau de Joux堡，法国 (© Ivoha/Alamy)
Overlooking the valley linking France to Switzerland (the Cluse de Pontarlier), Joux castle – with its keep, towers, drawbridges, surrounding walls and fort – offers fantastic evidence of the way fortifications have developed over the years. Built in the 11th century, then modified by Vauban in the 17th century, people will discover 10 centuries of history there.
2021-03-23
Satellite image of the Mania River in Madagascar (© NASA Earth Observatory image by Joshua Stevens, using Landsat data from the US Geological Survey)
马尼亚河的卫星图像，马达加斯加 (© NASA Earth Observatory image by Joshua Stevens, using Landsat data from the US Geological Survey)
A satellite view of the Mania River in Madagascar allows us to see a curious cloud pattern. It's common for cool, moist marine air to rise and form dense clouds over bodies of water, then for the clouds to evaporate as they drift over warmer, drier land. The opposite is happening here: Puffs of clouds are forming over land, but not over water. That's because Madagascar's tropical rainforests are warm and wet enough that evaporating moisture rises as the day heats up. When it rises high enough, the moisture encounters cooler air, which condenses the water into clouds. Generally speaking, clouds will form where the air is rising, which in this case is only over the land. Above the river, the air is cooler and descending, so no clouds are forming there.
Satellite image of the Mania River in Madagascar (© NASA Earth Observatory image by Joshua Stevens, using Landsat data from the US Geological Survey)
马尼亚河的卫星图像，马达加斯加 (© NASA Earth Observatory image by Joshua Stevens, using Landsat data from the US Geological Survey)
A satellite view of the Mania River in Madagascar allows us to see a curious cloud pattern. It's common for cool, moist marine air to rise and form dense clouds over bodies of water, then for the clouds to evaporate as they drift over warmer, drier land. The opposite is happening here: Puffs of clouds are forming over land, but not over water. That's because Madagascar's tropical rainforests are warm and wet enough that evaporating moisture rises as the day heats up. When it rises high enough, the moisture encounters cooler air, which condenses the water into clouds. Generally speaking, clouds will form where the air is rising, which in this case is only over the land. Above the river, the air is cooler and descending, so no clouds are forming there.
2021-03-24
Humpback whale mother pushes her sleeping calf to surface, Maui, Hawaii (© Ralph Pace/Minden Pictures)
座头鲸妈妈将她熟睡的幼鲸推到水面，夏威夷毛伊岛 (© Ralph Pace/Minden Pictures)
The family drama you see playing out here in the Pacific Ocean near Maui, Hawaii, is a humpback whale calf getting a little nudge from its mom. She presumably wants the sleepy youngster to practice surfacing, something these amazing marine mammals are famous for doing in dramatic fashion. Winter is calving season, when thousands of humpbacks swim to the warm waters off Hawaii, making them a common sight from November until April. Because they're known to hang around near the ocean's surface, breaching or slapping the water with their tails, humpbacks are a favorite of whale watchers everywhere.
Humpback whale mother pushes her sleeping calf to surface, Maui, Hawaii (© Ralph Pace/Minden Pictures)
座头鲸妈妈将她熟睡的幼鲸推到水面，夏威夷毛伊岛 (© Ralph Pace/Minden Pictures)
The family drama you see playing out here in the Pacific Ocean near Maui, Hawaii, is a humpback whale calf getting a little nudge from its mom. She presumably wants the sleepy youngster to practice surfacing, something these amazing marine mammals are famous for doing in dramatic fashion. Winter is calving season, when thousands of humpbacks swim to the warm waters off Hawaii, making them a common sight from November until April. Because they're known to hang around near the ocean's surface, breaching or slapping the water with their tails, humpbacks are a favorite of whale watchers everywhere.