In Darkness You May Find Light

This false-color composite image, constructed from data obtained by NASA's Cassini spacecraft in the near-infrared light, shows the glow of auroras streaking out about 600 miles from the cloud tops of Saturn's south polar region. More information below. Click the photo for a wallpaper version. Credit: NASA/JPL/U. of Arizona/U. of Leicester

I had a craving for General Tso’s chicken last night and stopped at the Beijing Restaurant to pick up an order. As I was writing the check, the fellow behind the counter remarked about the early darkness. “It’s only 8, and, look, it’s already dark outside,” he said. And he was right. With the sun setting now around 7 and twilight over by 8:30, access to the night sky has expanded into the prime TV viewing hours. Looking for an excuse to step away from the TV? Hint, hint.

Earlier nights mean young children can go out for a look at the stars and planets before bedtime. If you haven’t already, consider taking your child for a walk at night. If the moon is out, it provides a friendly glow to light the way. Even if you’re only familiar with the Big Dipper or Orion, there’s much joy in sharing thoughts and speculations about the stars with children. They’ll have dozens of questions of course, each one an opportunity to share knowledge or honestly admit ignorance. I used to love it when my daughters saw or heard something that scared them. They’d give a little shout and then cling to my side for a minute or two. If that doesn’t make you feel like a dad, I don’t know what does.

When children grow older and become teens, walks under the stars are a chance for both you and them to share what you did that day or talk over school, boy problems and all the rest. Darkness provides a cloak of anonymity that encourages kids who are reticent to feel more at ease. And there’s nothing like the whole universe over your head to give you the space you need to wrangle through an issue. Since they’re nearly all grown up and have plans of their own, night walks with my girls are becoming fewer and fewer, but I remain hopeful. I always ask if they’d like to join me, and still occasionally get a yes.

This movie, made from data obtained by NASA’s Cassini spacecraft, shows Saturn’s southern aurora shimmering over approximately 20 hours as the planet rotates.

NASA released a new set of photos and a video this week of auroras in the south polar atmosphere of Saturn. Like Earth, Saturn’s magnetic field channels particles from the solar wind toward the planet’s north and south poles where they collide with atoms in the tenuous upper atmosphere. When the atoms settle back down, each emits a brief flash of light. Multiply those flashes by billions of atoms and you get great glowing curtains and rays of dancing light in the Saturnian sky. Unlike Earth, Saturn’s auroras can also get started when one of its moons moves through the dilute electron and proton soup in Saturn’s magnetic field, setting off rippling waves of energy that stimulate an auroral storm in the atmosphere below.

The green color in the video and photo is light from hydrogen atoms photographed in near-infrared light or light that’s just beyond the reddest thing we can see with our eyes. Even though invisible, we sense it as heat. The heat from your oven burner is a powerful infrared emitter. The rings are blue because they reflect sunlight at a particular infrared wavelength, while the globe is red because of heat rising from deeper within the atmosphere. Those dark features striping the globe are clouds and storms seen in silhouette against the heat energy coming from below. “Fascinating,” as Star Trek’s Spock might say.

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