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Moon and Saturn

March 28, 2016

A triangle of three bright lights stands below the Moon at first light tomorrow. The closest point to the Moon is the planet Saturn, to the lower left of the Moon. The bright orange planet Mars is farther to the lower right of the Moon, with the orange star Antares at the bottom of the triangle.

Saturn is one of the solar system’s giants — it’s about nine times Earth’s diameter. It probably consists of a dense core surrounded by layers of hydrogen and helium. Motions within a layer of metallic hydrogen create a magnetic field that extends far into space.

[SFX: Saturn audio] Interactions between the magnetic field and the solar wind create radio waves, which were recorded by the Cassini spacecraft, then converted to sound.

The magnetic field forms a “bubble” that deflects much of the solar wind, causing it to stream around the planet. But some of the wind’s charged particles get through. They’re guided toward Saturn’s magnetic poles, where they form bright auroras — the shimmering curtains known on Earth as the northern and southern lights.

Saturn’s magnetic poles are almost exactly aligned with its geographic poles, which isn’t the case with any other planet. Earth’s magnetic field, for example, is tilted several degrees away from its axis. But so far, scientists aren’t sure why Saturn’s field is so different.

Again, look for Saturn — a giant planet inside a giant magnetic bubble — near the Moon at first light tomorrow.

Script by Damond Benningfield

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