Leonid meteors to shower night sky on Tuesday

Look out for Leo.

If you don’t catch the meteor showers early tomorrow morning, you might have a second chance after midnight tomorrow night.

Like every year around this time, the earth is in a position to pass through a stream of Leonid meteors. This year, Oakland’s in for a show.

Meteor gazers might have seen up to 500 meteors per hour from 1 this morning to about sunrise, and those hours will be the best bet for viewing the meteors Wednesday morning.

Fewer meteors might appear in the sky then, but they will probably be more visible than during other hours.

The forecast for after midnight tonight is partly cloudy until 3 a.m. After that, it should be completely clear.

Viewers who stay up late tonight might be able to view the meteors with some favorable weather conditions, as well as a moon that was just new yesterday.

Michael Wood-Vasey, an assistant professor in Pitt’s astronomy department, said the meteors come from a particle stream, which trails behind the 55P/Tempel-Tuttle comet.

The orbits of the earth and the comet overlap roughly every November.

“Not in a way that they’ll ever collide,” Wood-Vasey said, “but merely just that the debris that gets left behind from the comet streams across the orbit of the earth.”

The comet particles fly at an average speed of 150,000 miles per hour across the sky.

When the particles hit the atmosphere, they compress the air in front of them to very high temperatures, breaking apart in their fiery trajectory and leaving the glowing flares and streaks of a meteor shower.

The meteors, all coming from one stream, appear to originate from one point in the sky, called the radiant.

In this case, that point is in the middle of the “lion” constellation, Leo, which is why astronomers call these meteors Leonids.

Leo rises above the northeastern horizon between 1 and 3 a.m.

It takes 1,000 visible meteors per hour to constitute a meteor storm. Depending on the year, these Leonids range from modest to spectacular.

Wood-Vasey recalled the storms from 1998 and 2001, during which the number of meteors per hour reached up to 3,000.

At an estimated 500 visible meteors per hour, this year’s Leonids will constitute a half-storm — still a strong display.

Wood-Vasey said Pitt’s observatory will not do anything particularly special concerning this well-known meteor stream.

“One of the interesting things about meteors is they really don’t need a telescope and don’t even need binoculars just to enjoy them,” he said. “You just want to be able to see the entire sky, and the human eye is a very good instrument for doing that.”

The highest number of meteors was visible around 4:45 p.m. yesterday, meaning the Leonids’ peak hour was effectively invisible for onlookers in North America and Europe.

Observers in Asia had the equivalent of front-row seats because the peak happened during predawn hours there.

Wood-Vasey still recommends Pitt students venture out to catch a glimpse of the half-storm.

“It’s just always hard to predict exactly what part of the stream is going to be out there because we don’t have all these multiple dust particles mapped out,” he said. “It’s almost just when we pass through them that we really have a sense of what their structure is.”

He said students should look for a place with a good amount of open sky — and that having a blanket on which to lie down and a bit of patience can make the difference.

Bring something warm, as temperatures are forecasted to be around 45 degrees early Wednesday morning.

Just remember not to call the meteors “meteorites” — unless they hit the earth.