Meteor Shower

The “Annual Taurid meteors shower may have led to ice age ... - The Gaea Times”

2010-04-10T15:13:00.001-07:00

The “Annual Taurid meteors shower may have led to ice age ... - The Gaea Times”

Annual Taurid meteors shower may have led to ice age ... - The Gaea Times

Posted: 08 Apr 2010 12:13 AM PDT

WASHINGTON - Thousands of Tunguska-sized cometary fragments struck the earth for over an hour 13,000 years ago, leading to a dramatic cooling of the planet and extinction of ice age mammals, according a new study.

The cooling, by as much as 8 degrees Celsius, interrupted the warming which was occurring at the end of the last ice age and caused glaciers to readvance.

"A large comet has been disintegrating in the near-Earth environment for the past 20,000 to 30,000 years, and running into thousands of fragments from this comet is a much more likely event than a single large collision," said Bill Napier, professor at the Cardiff University Astrobiology Centre, who conducted the study.

Evidence has been found that this catastrophic change was associated with some extraordinary extraterrestrial event.

These findings suggest that the catastrophic changes were caused by the impact of an asteroid or comet four km across on the Laurentide ice sheet, which at that time covered what would become Canada and the northern part of the US.

The cooling lasted over a thousand years, and its onset coincides with the rapid extinction of 35 genera of North American mammals, as well as the disruption of the Palaeoindian culture.

The chief objection to the idea of a big impact is that the odds against the earth being struck by an asteroid this large only 13,000 years ago are a thousand to one.

Napier has now come up with an astronomical model, which accounts for the major features of the catastrophe without involving such an improbable event.

The new model indicates that such an encounter would last for about an hour during which thousands of impacts would take place over continental dimensions, said a Cardiff release.

Each of these impacts released the energy of a megaton-class nuclear bomb, generating the extensive wildfires, which took place at that time.

The new model has been presented in the journal Monthly Notices of the Royal Astronomical. (ANI)

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plus 1 more, “Embracing coffee with Lowells Observatory & Lyrids ... - Examiner”

2010-04-09T15:29:00.001-07:00

plus 1 more, “Embracing coffee with Lowells Observatory & Lyrids ... - Examiner”

Embracing coffee with Lowells Observatory & Lyrids ... - Examiner

Posted: 08 Apr 2010 11:43 PM PDT

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Fill your coffee thermos with Macy's nutty smooth dark espresso roast with a bit of milk and let your celestial instincts whisk you away to the Mars Hill Lowell Observatory in Flagstaff Arizona at 1400 W. Mars Hill Road, on April 21 2010, from 5:30 PM to 9:30 PM! Enjoy a program focused on meteor showers, as well as the upcoming Lyrid Meteor shower. Late April, every year the earth passes through the dusty tail of Comet Thatcher, which causes a breath taking meteor shower!

The best time to watch is late at night and before dawn. There should be approximately ten to twenty meteors per hour. The Lyrid meteors seem to stream from the bright star Vega in the constellation of Lyra.

Chug your Macy's espresso coffee and Bask in the glow of Saturn, nebulae and the stars clusters, either through the telescopes eyes or live video. You may also wish to gather in the portable planetarium for a program about our vast universe.

Don't miss out on nature's delights, or its fresh roasted coffee beans!

Please sample more cerebral literature here.

Lowells Observatory

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2010 Major Meteor Showers - PhysOrg

Posted: 08 Apr 2010 07:40 PM PDT

Once you get there, search for the darkest patch of sky you can find, as meteors can appear anywhere overhead. The path the meteors will travel will always be away from the constellation for which the shower was named. This apparent point of origin is called the "radiant." For example, meteors during a Leonid meteor shower will appear to rain in from the constellation Leo. (Note: this is an optical illusion, and the constellation only serves as a helpful guide in the night's sky. The constellation is not the actual source of the meteors.)

Now a word about the moon -- it is not your (the expectant meteor watcher's) friend. Light reflecting off a bright moon can be just as detrimental to good meteor viewing as those bright lights of the big city. There is nothing you can do except howl at the moon, so you will have to put up with it or wait until the next favorable date. Even though the 2010 Perseids and Geminids will be sharing the night sky with the moon, they are still expected to produce more visible meteor activity than other major showers without a moon.

Of the seven major meteor showers remaining in 2010 (the Quadrantids occurred in early January 2010), some are more major than others. For example, April's Lyrids are expected to produce about 15 meteors an hour at their peak for observers viewing in good conditions. Now, if you put the same observer in the same good conditions during a higher-rate shower like August's Perseids or December's Geminids, that observer could witness up to 100 meteors an hour during peak activity.

The meteor showers listed below will provide casual meteor observers with the most bang for their buck. They are easiest to observe and provide the most activity. All these showers can be best enjoyed in the hours after midnight.

2010 Meteor Showers

Lyrids
Comet of origin: C/1861 G1 Thatcher
Radiant: constellation Lyra -- which rises in the northeast at about 10 p.m.
Active: April 16-25
Peak Activity: Early Morning April 22
Peak Activity Meteor Count: Approximately 15 meteors per hour
Time of optimal viewing: On the night of expected peak activity (April 22) a moon between half and full will set between 1 and 2 a.m. for most of the northern hemisphere, leaving a dark sky until dawn. Viewers in the southern hemisphere will receive a smattering of Lyrid meteors compared to viewers north of the equator.
Meteor Velocity: Lyrid meteors hit the atmosphere at a moderate speed of 48 kilometers (30 miles) per second. They often produce luminous trains of dust that can be observed for several seconds.

Eta Aquarids
Comet of origin: 1P Halley
Radiant: constellation Aquarius
Active: April 28-May 21
Peak Activity: Early morning May 6
Peak Activity Meteor Count: Up to approximately 60 meteors per hour (southern hemisphere), 15 meteors per hour (northern hemisphere). A less-than-half-full moon is expected to severely hamper viewing
Time of optimal viewing: Just before dawn
Meteor Velocity: 67 kilometers (42 miles) per second

Delta Aquarids
Comet of origin: unknown
Radiant: constellation Aquarius
Active: July 14-Aug. 18
Peak Activity: No definite peak, but nights surrounding July 30 may be best
Peak Activity Meteor Count: Approximately 15 meteors per hour (northern hemisphere). Unfortunately, an almost-full moon will obscure many a meteor during this year's peak.
Time of optimal viewing: An hour or two before dawn. Meteor watchers in the southern hemisphere and in the northern hemisphere's tropical latitudes will enjoy the best views.
Meteor Velocity: 42 kilometers (26 miles) per second

Perseids
Comet of origin: 109P/Swift-Tuttle
Radiant: constellation Perseus
Active: Perseids begin to rise early August.
Peak Activity: Night of Aug. 12-13
Peak Activity Meteor Count: Approximately 50 meteors per hour
Time of optimal viewing: Crescent moon will set early in the evening, allowing for dark skies all the way up until peak viewing just before dawn
Meteor Velocity: 61 kilometers (38 miles) per second
Note: The Perseid meteor shower is one of the most consistent performers and considered by many as this year's best shower. The meteors they produce are among the brightest of all meteor showers.

Leonids
Comet of origin: 55P/Tempel-Tuttle
Radiant: constellation Leo
Active: Nov. 7-28
Peak Activity: Night of Nov. 17-18
Peak Activity Meteor Count: Approximately 15 per hour
Time of optimal viewing: A half-full moon sets after midnight, allowing for a dark sky. Best viewing time will be just before dawn.
Meteor Velocity: 71 kilometers (44 miles) per second
Note: The Leonids have not only produced some of the best meteor showers in history, but have sometimes achieved the status of meteor storm. During a Leonid meteor storm, many thousands of meteors per hour can shoot across the sky. Scientists believe these storms recur in cycles of about 33 years, though the reason is unknown. The last documented Leonid meteor storm occurred in 2002.

Geminids
Comet of origin: 3200 Phaethon
Radiant: constellation Gemini
Active: Dec. 4-16
Peak Activity: Night of Dec 13 -14
Peak Activity Meteor Count: Approximately 50 meteors per hour
Time of optimal viewing: 2 a.m.
Meteor Velocity: 35 kilometers (22 miles) per second
Note: Generally, the Geminids or August's Perseids provide the best meteor shower show of the year. Geminids are usually considered the best opportunity for younger viewers because the show gets going around 9 or 10 p.m. Unfortunately the moon does not set until after midnight this year, making for the possibility of drooping eyelids from the pre-teen set.

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plus 1 more, “Annual Taurid meteors shower may have led to ice age ... - The Gaea Times”

2010-04-08T15:30:00.001-07:00