2009 Orionid Meteor Shower

This is something to get up for if you have a good watching post to use. It will be there for Wednesday through Friday. The second link shows where to look, but just left of Orion is more than good enough.

The 2009 Orionid Meteor Shower

10.19.2009

http://science.nasa.gov/headlines/y2009/19oct_orionids.htm?list1109684

October 19, 2009: The Orionid meteor shower peaks this week and it could be a very good show.

"Earth is passing through a stream of debris from Halley's Comet, the source of the Orionids," says Bill Cooke of NASA's Meteoroid Environment Office. "Flakes of comet dust hitting the atmosphere should give us dozens of meteors per hour."

The best time to look is before sunrise on Wednesday, Oct. 21st. That's when Earth encounters the densest part of Halley's debris stream. Observing is easy: Wake up a few hours before dawn, brew some hot chocolate, go outside and look up. No telescope is required to see Orionids shooting across the sky.

Orionids appear every year around this time when Earth orbits through an area of space littered with debris from the ancient comet. Normally, the shower produces 10 to 20 meteors per hour, a modest display. The past few years, however, have been much better than usual.

"Since 2006, the Orionids have been one of the best showers of the year, with counts of 60 or more meteors per hour," says Cooke.

According to Japanese meteor scientists Mikiya Sato and Jun-ichi Watanabe, 2006 marked Earth's first encounter with some very old debris. "We have found that the [elevated activity of 2006] was caused by dust trails ejected from 1P/Halley in 1266 BC, 1198 BC, and 911 BC," they wrote in the August 2007 edition of Publications of the Astronomical Society of Japan. In their paper "Origin of the 2006 Orionid Outburst," Sato and Watanabe used a computer to model the structure and evolution of Halley's many debris streams stretching back in time as far as 3400 years. The debris that hit Earth in 2006 was among the oldest they studied and was rich in large fireball-producing meteoroids.

Repeat encounters produced good displays in 2007 and 2008—and "the meteoroids are expected to approach Earth [again] in 2009," say Sato and Watanabe. They note that these old broad streams tend to produce equally broad showers, lasting several nights around the peak. So, if clouds interfere on the 21st, try again on the 22nd or 23rd.

http://science.nasa.gov/headlines/y2009/images/orionids/skymap_north_big.gif

Above: Orionid meteors stream from the elbow of Orion the Hunter. Because the shower's radiant point is close to the celestial equator, sky watchers in both hemispheres can enjoy the show. [larger map]

The phase of the Moon favors a good show. The Moon is almost new and completely absent from the pre-dawn sky at the time of the shower's peak. Bright moonlight will not be a problem.

Last but not least, the display will be framed by some of the prettiest stars and planets in the night sky. In addition to Orionids, you'll see brilliant Venus, red Mars, the dog star Sirius, and bright winter constellations such as Orion, Gemini and Taurus. Even if the shower is a dud, the rest of the sky is dynamite.

Set your alarm and enjoy the show.

Author: Dr. Tony Phillips Credit: http://science.nasa.gov/

Green Comet Lulin's Passage

This is a great story reminding us that the human eyeball is out there working no matter what else we might be doing. This is a great discovery and the green color is something I have never before been made aware of.
It is times like this that I personally miss the old farm that I grew up on. The midnight sky in the month of January was spectacular. Orion filled the south and the milky wave poured across the heavens in a dash of cream. In such environs this comet will be soon visible.

A surprise for me is the apparent scale of the comet described. It is as big as the atmosphere of Jupiter.

This means that when it becomes time to terraform Venus, one such comet will be perfect. This is a much more tractable problem. Find the right size far enough out and give it a nudge in the right direction. The gravity well of Venus will do the rest.

It occurs to me that each passage through the sun’s gravity well should strip off a lot of the associated gas and even leaves a lot behind by interaction with the solar flux, incrementally altering the orbit. I know that this has been postulated before but this particular comet is ideal for study of initial effects. Too bad we do not have a craft to track its passage.

02.04.2009
Green Comet Approaches Earth

http://science.nasa.gov/headlines/y2009/04feb_greencomet.htm?list1109684

February 4, 2009: In 1996, a 7-year-old boy in China bent over the eyepiece of a small telescope and saw something that would change his life--a comet of flamboyant beauty, bright and puffy with an active tail. At first he thought he himself had discovered it, but no, he learned, two men named "Hale" and "Bopp" had beat him to it. Mastering his disappointment, young Quanzhi Ye resolved to find his own comet one day.

And one day, he did.

Fast forward to a summer afternoon in July 2007. Ye, now 19 years old and a student of meteorology at China's Sun Yat-sen University, bent over his desk to stare at a black-and-white star field. The photo was taken nights before by Taiwanese astronomer Chi Sheng Lin on "sky patrol" at the Lulin Observatory. Ye's finger moved from point to point--and stopped. One of the stars was not a star, it was a comet, and this time Ye saw it first.

Comet Lulin, named after the observatory in Taiwan where the discovery-photo was taken, is now approaching Earth. "It is a green beauty that could become visible to the naked eye any day now," says Ye.

Amateur astronomer Jack Newton sends this photo from his backyard observatory in Arizona:

http://science.nasa.gov/headlines/y2009/images/greencomet/Jack-Newton1.jpg

"My retired eyes still cannot see the brightening comet," says Newton, "but my 14-inch telescope picked it up quite nicely on Feb. 1st."

The comet makes its closest approach to Earth (0.41 AU) on Feb. 24, 2009. Current estimates peg the maximum brightness at 4th or 5th magnitude, which means dark country skies would be required to see it. No one can say for sure, however, because this appears to be Lulin's first visit to the inner solar system and its first exposure to intense sunlight. Surprises are possible.

Lulin's green color comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.

In 1910, many people panicked when astronomers revealed Earth would pass through the cyanogen-rich tail of Comet Halley. False alarm: The wispy tail of the comet couldn't penetrate Earth's dense atmosphere; even it if had penetrated, there wasn't enough cyanogen to cause real trouble. Comet Lulin will cause even less trouble than Halley did. At closest approach in late February, Lulin will stop 38 million miles short of Earth, utterly harmless.

To see Comet Lulin with your own eyes, set your alarm for 3 am. The comet rises a few hours before the sun and may be found about 1/3rd of the way up the southern sky before dawn. Here are some dates when it is especially easy to find:

http://science.nasa.gov/headlines/y2009/images/greencomet/skymap_north_lulin_06feb09.gif

Feb. 6th: Comet Lulin glides by Zubenelgenubi, a double star at the fulcrum of Libra's scales. Zubenelgenubi is not only fun to say (zuBEN-el-JA-newbee), but also a handy guide. You can see Zubenelgenubi with your unaided eye (it is about as bright as stars in the Big Dipper); binoculars pointed at the binary star reveal Comet Lulin in beautiful proximity. [sky map]

Feb. 16th: Comet Lulin passes Spica in the constellation Virgo. Spica is a star of first magnitude and a guidepost even city astronomers cannot miss. A finderscope pointed at Spica will capture Comet Lulin in the field of view, centering the optics within a nudge of both objects. [sky map]

Feb. 24th: Closest approach! On this special morning, Lulin will lie just a few degrees from Saturn in the constellation Leo. Saturn is obvious to the unaided eye, and Lulin could be as well. If this doesn't draw you out of bed, nothing will. [sky map]

Ye notes that Comet Lulin is remarkable not only for its rare beauty, but also for its rare manner of discovery. "This is a 'comet of collaboration' between Taiwanese and Chinese astronomers," he says. "The discovery could not have been made without a contribution from both sides of the Strait that separates our countries. Chi Sheng Lin and other members of the Lulin Observatory staff enabled me to get the images I wanted, while I analyzed the data and found the comet."

Somewhere this month, Ye imagines, another youngster will bend over an eyepiece, see Comet Lulin, and feel the same thrill he did gazing at Comet Hale-Bopp in 1996. And who knows where that might lead...?
"I hope that my experience might inspire other young people to pursue the same starry dreams as myself," says Ye.