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Moon in the Middle

March 28, 2015

The gibbous Moon passes through the middle of a triangle of bright astronomical objects tonight: the planet Jupiter, the star Procyon, and the “twins” of Gemini.

The brightest point of the triangle is Jupiter, which is to the left of the Moon as darkness falls. Only the Moon and the planet Venus outshine it, so it’s easy to find.

Jupiter shines so brightly because it’s the biggest planet in the solar system — about 11 times wider than Earth. And it’s wrapped in clouds that reflect about half of the sunlight that strikes them back out into space — giving this hefty planet a hefty appearance in the night sky.

Procyon is the second-brightest member of the triangle, standing below the Moon. It’s the leading light of Canis Minor, the little dog. It’s only about 11 light-years away, which makes it one of our closer stellar neighbors. It’s actually two stars — the bright one that’s visible to the eye alone, and a “dead” companion that’s visible only through a telescope.

The triangle’s final point is above the Moon. We’re stretching things a bit, because it actually consists of two stars: Pollux and Castor, the twins of Gemini. Pollux is closer to the Moon, and it’s also the brighter of the two.

Pollux is a cool, bloated star that’s nearing the end of its life. And Castor is a system of six stars or more, although their light blurs together to make a single pinpoint — one of the bright lights that surround the Moon tonight.


Script by Damond Benningfield, Copyright 2015

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