Friday, 16 November 2012

Moonless nights for November 2012 Leonid meteor shower

The image at the top of this post is a famous woodcut of the 1833 Leonid meteor storm. No Leonid storm is expected this year, but if you watch in the next few mornings you might see a few meteors! The young crescent moon will set soon after sunset tonight (November 15, 2012), leaving dark skies for this year’s November 2012 Leonid meteor shower. Tonight is not the peak of the shower. The peak should come between midnight and dawn on Saturday morning, November 17. But you’re likely to see Leonids tonight, too, as the shower climbs toward its peak. Just remember, this meteor shower is for night owls and early birds. As a rule of thumb, the Leonids intensify after midnight, and the greatest numbers fall just before dawn.

In fact, all this weekend should be good for watching this annual shower. Again, the best viewing window should be between midnight and dawn Saturday, November 17. Even so, meteor showers are notorious for defying expectations, and any prediction should be regarded as a best guess – not an ironclad guarantee. If it’s clear, you might see nearly as many meteors in the predawn darkness on Friday, November 16 or Sunday, November 17. Typically, you see 10 to 15 meteors per hour in the darkness before dawn.

The moon won’t interfere with this year’s Leonid display. In fact, it’ll be quite a challenge, finding the young moon with the planet Mars at nightfall these next few evenings. As seen from mid-northern latitudes, the thin waxing crescent moon and the red planet Mars sit low in the southwest sky about an hour after sunset and follow the sun beneath the horizon shortly after dark.

It’ll be much easier to see three other visible planets tonight: Jupiter, Saturn and Venus The blazing planet Jupiter rises in the east-northeast at early evening, and then stays out all night long. Saturn and Venus appear low in the southeast in the predawn darkness, when the Leonids typically produce the most meteors. For a chart displaying Venus and Saturn, see tomorrow’s night sky post.

The Leonid meteor shower is named after the constellation Leo the Lion. If you trace the paths of the Leonid meteors backward, they all seem to radiate from this constellation – near the star Algieba. But you don’t have to identify the constellation Leo to watch the Leonids, for these meteors fly any which way through the nighttime sky. Generally, the higher that Leo climbs in the sky, the more Leonid meteors that you’ll see. At this time of year, the Lion climbs highest in the sky just before dawn.

Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.

Simply find a dark, open sky and sprawl out comfortably in a reclining lawn chair. No special equipment is necessary. You don’t have to know the constellations. Every year in November, the Earth crosses the orbital path of Comet Tempel-Tuttle and bits and pieces from this comet burn up as Leonid meteors in the Earth’s upper atmosphere.

Leonid meteor shower in history. The Leonid shower has produced some of history’s most impressive displays of meteors. The best displays in recent history took place in 1833, 1866 and 1966. Whenever our planet Earth plows through an unusually thick clump of debris in space – left behind by comets in orbit around the sun – hundreds of thousands of meteors can streak across our nighttime sky. For instance, observers in the southwest United States reported seeing 40 to 50 meteors per second (that’s 2,400 to 3,000 meteors per minute!) during a span of 15 minutes on the morning of November 17, 1966.

Bottom line: Expect to see a decent sprinkling of Leonid meteors in the predawn sky during the next several days. The peak night will probably be from late evening Friday, November 16 until dawn Saturday, November 17. With no moon to ruin the show, you might see about 10 to 15 meteors per hour. For the best views, find a dark country sky.

- EarthSky

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