Saturday, July 15th, 2017

One Way to Heat the Corona

The Sun’s corona is incredibly hot, with temperatures of 1-2 million degrees, and yet we don’t really understand how it’s heated. Thermonuclear fusion keeps the center of the Sun comparably hot, but between the Sun’s interior and its outer coronal layers lies the much cooler photosphere and chromosphere, where the temperature drops to a chilly 6000 degrees or so.  This cool layer sandwiched between the Sun’s interior furnace and its hot corona presents a problem for heating the corona. Heat can’t flow in its normal way through this cool zone, and so it’s difficult to understand how the energy can get […]

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Friday, June 23rd, 2017

Two Moons Away

Tonight at approximately 10:30 pm EDT, the Moon passes between the Sun and the Earth. No eclipse though — the alignment isn’t quite right, and so instead it’s just a boring New Moon. New Moons are boring because the side facing us isn’t illuminated by the Sun, and so the Moon looks dark. There’s literally nothing to see. The Moon orbits the Earth while the Earth orbits the Sun, so a New Moon occurs once per orbit, or about once every 29.5 days (hence the term “month”). If the Moon’s orbit around the Earth and the Earth’s orbit around the […]

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