Tuesday, April 29, 2014

Possible meteor shower May 23-24 as Earth passes through dust trail of 209P/LINEAR

Composite photo of Lyrid meteor shower and non-Lyrids taken with a NASA all-sky camera April 21-23, 2012. 

A new meteor shower emanating from Camelopardalids near the North Star is expected to light up the skies the morning May 24 around 2 a.m. CDT (7 UT). 

Credit: NASA /MSFC /Danielle Moser

On Friday night/early Saturday May 23-24 skywatchers across the U.S. and southern Canada may witness the birth of a brand new meteor shower.

If predictions hold true, Earth will pass through multiple tendrils of dust and pebbly bits left behind by comet 209P/LINEAR, firing up a celestial display on par with the strongest showers of the year. Or better.

Earlier predictions called for a zenithal hourly rate or ZHR of 1,000 per hour, pushing this shower into the 'storm' category.

ZHR is an idealized number based on the shower radiant located at the zenith under ideal skies.

The actual number is lower depending on how far the radiant is removed from the zenith and how much light pollution or moonlight is present.

Peter Jenniskens
Meteor expert Peter Jenniskens of NASA's SETI Institute and Finland's Esko Lyytinen first saw the possibility of a comet-spawned meteor storm and presented their results in Jenniskens' 2006 book Meteor Showers and Their Parent Comets.

Esko Lyytinen
Quanzhi Ye and Paul Wiegert (University of Western Ontario) predict a weaker shower because of a decline in the comet's dust production rate based on observations made during its last return in 2009. They estimate a rate of ~200 per hour.

On the bright side, their simulations show that the comet sheds larger particles than usual, which could mean a shower rich in fireballs. Other researchers predict rates between 200 and 40o per hour.

At the very least, the Camelopardalids – the constellation from which the meteors will appear to originate – promise to rival the Perseids and Geminids, the year's richest showers.

Approximate location of the radiant (blue) of the 209P/LINEAR shower at the peak of the brief maximum around 2 a.m. CDT May 24. 

Between 100-400 meteors may radiate from the dim constellation of Camelopardalids near the North Star. 

This map shows the sky from the central U.S. 

Created with Stellarium

Comet 209P/LINEAR, discovered in Feb. 2004 by the automated Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) sky survey, orbits the sun every 5.04 years with an aphelion (most distant point from the sun) near Jupiter.

The OSIRIS-REx spacecraft with its sample-collecting arm resembles a standing heron and inspired Michael Toler Puzio’s inventive name for the asteroid that the OSIRIS-REx space mission will visit. 

Credit: NASA/Goddard Flight Center/University of Arizona.

In 2012, during a relatively close pass of that planet, Jupiter perturbed its orbit, bringing it to within 280,000 miles (450,000 km) of Earth's orbit.

That set up a remarkably close encounter with our planet on May 29 when 209P/LINEAR will cruise just 5 million miles (8 million km) from Earth to become the 9th closest comet ever observed.

Multiple debris trails shed by the comet as long ago as the 18th century will intersect our planet's path 5 days earlier, providing the material for the upcoming meteor shower/storm.

Read the full article here

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