2020年10月 - 星空迷

栖息在斯诺希尔岛的成年帝企鹅和幼崽，南极 Emperor penguin adults and chicks at the Snow Hill Island rookery, Antarctica (© Martin Ruegner/Getty Images)

Hey, you two in the front!

For World Teachers' Day, we're taking you to a class of emperor penguin chicks getting a lesson from a couple of wise adults—at least that's how it looks to us. All kidding aside, the celebration has a special significance this year. Educators dedicate their lives to engaging the minds of young and old alike, all the while sparking curiosity about the world around us. But with in-person classes widely curtailed due to the coronavirus pandemic, teachers have had to adapt their instruction methods, including the implementation of remote learning. More than ever we're grateful for their efforts, including their support to parents who are contributing at home.

Speaking of remote learning, the penguins in this photo live and learn in Antarctica at their breeding colony on Snow Hill Island. One thing we've learned on this World Teachers' Day: A group of chicks is called a rookery, but when mature, they become a waddle of adult penguins, a term that also describes their graceless walking gait. About that gait: Penguins rock side-to-side to raise their center of gravity and compensate for their wide feet and squat legs. You might think they expend a lot of energy getting around, but the percentage of energy retained per penguin stride—or recovery rate—is 80%. In comparison, the recovery rate for humans is a mere 65% (the two penguin chicks snoozing in today's photo probably already know that).

木星及木卫一的蒙太奇图像 Montage of images of Jupiter and its volcanic moon Io (© NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Goddard Space Flight Center)

Infrared Jupiter, erupting Io

To celebrate World Space Week, we're featuring this montage of images of Jupiter courtesy of the New Horizons probe's flyby of the planet in 2007. If Jupiter looks a little different than you're used to seeing, it's because it was imaged using the space probe's near-infrared imaging spectrometer. In this false-color image, Jupiter's high-altitude clouds, like its stormy Great Red Spot, are rendered white, while deeper cloud formations take on reddish hues. The planet's innermost moon, Io, is captured in a true-color composite image during one of its frequent volcanic eruptions. A close look will show lava is glowing red beneath the blue and white plume of particles being ejected into the moon's thin atmosphere.

Space Week is a UN-recognized event that runs each year from October 4, which is the anniversary of the launch of Sputnik in 1957, to October 10, the anniversary of the signing of the Outer Space Treaty in 1967. This year's theme is 'Satellites Improve Life.'

从波迪安西之路的洛特谷中望向圣西尔克·拉波皮教堂，法国洛特 (© Reinhard Schmid/Huber/eStock Photo)

Owens River and the Sierra Nevada near Bishop, California (© Interfoto/Danita Delimont)

A wild and scenic scene

Some of our nation's most treasured rivers are protected thanks to a program that was first established on this day in 1968. The Wild and Scenic Rivers Act aims to preserve rivers with 'outstanding natural, cultural, and recreational values in a free-flowing condition for the enjoyment of present and future generations.' That's something we can get behind. This national system now protects more than 13,000 miles of 226 rivers. They flow through 41 states and the Commonwealth of Puerto Rico, from Idaho's Salmon River to the Missouri River in the Midwest to the Allagash River in Maine. Today's homepage visits the Owens River, near the Sierra Nevada in eastern California. About 19 miles of the Owens River headwaters were protected as a Wild and Scenic River in 2009, ensuring we'll see views like this for years to come.

Mid-Autumn Festival

The Mid-Autumn Festival, or Moon Festival, is a celebration of the autumn harvest observed by the Chinese and other Asian peoples. It falls on the 15th day of the eighth lunar month, the full moon closest to the fall equinox. Originally a plea to the gods for rains to ensure a good harvest next year, Mid-Autumn Festival has become a more secular bit of autumn fun, with children and adults gathering to give thanks, eat sweet mooncakes, and light lanterns like the hand-painted ones we're looking at here from a previous celebration in Singapore. This year, the Mid-Autumn Festival coincidentally lands on another Chinese holiday, National Day.