Miscellaneous tidbits

[Brad Reddekopp]

This one sounds like it could be pretty cool:

Feb. 13, 2008: On Wednesday evening, February 20th, the full Moon over the Americas will turn a delightful shade of red and possibly turquoise, too. It's a total lunar eclipse—the last one until Dec. 2010.

The Sun goes down. The Moon comes up. You go out and look at the sky. Observing the eclipse is that easy. Maximum eclipse, and maximum beauty, occurs at 10:26 pm EST (7:26 pm PST).

A lunar eclipse happens when the Moon passes through the shadow of Earth. You might expect the Moon to grow even more ashen than usual, but in fact it transforms into an orb of vivid red.

Why red? That is the color of Earth's shadow.

Consider the following: Most shadows we're familiar with are black or gray; step outside on a sunny day and look at your own. Earth's shadow is different because, unlike you, Earth has an atmosphere. The delicate layer of dusty air surrounding our planet reddens and redirects the light of the sun, filling the dark behind Earth with a sunset-red glow. The exact tint--anything from bright orange to blood red is possible--depends on the unpredictable state of the atmosphere at the time of the eclipse. "Only the shadow knows," says astronomer Jack Horkheimer of the Miami Space Transit Planetarium.

Transiting the shadow's core takes about an hour. The first hints of red appear around 10 pm EST (7 pm PST), heralding a profusion of coppery hues that roll across the Moon's surface enveloping every crater, mountain and moon rock, only to fade away again after 11 pm EST (8 pm PST). No special filter or telescope is required to see this spectacular event. It is a bright and leisurely display visible from cities and countryside alike.

While you're watching, be alert for another color: turquoise. Observers of several recent lunar eclipses have reported a flash of turquoise bracketing the red of totality.

"The blue and turquoise shades at the edge of Earth's shadow were incredible," recalls amateur astronomer Eva Seidenfaden of Trier, Germany, who took the picture at right during the European lunar eclipse of March 3-4, 2007. Dozens of other photographers have documented the same phenomenon.

The source of the turquoise is ozone. Eclipse researcher Dr. Richard Keen of the University of Colorado explains: "During a lunar eclipse, most of the light illuminating the moon passes through the stratosphere where it is reddened by scattering. However, light passing through the upper stratosphere penetrates the ozone layer, which absorbs red light and actually makes the passing light ray bluer." This can be seen, he says, as a soft blue fringe around the red core of Earth's shadow.

To catch the turquoise on Feb. 20th, he advises, "look during the first and last minutes of totality." That would be around 10:01 pm EST and 10:51 pm EST (7:01 and 7:51 pm PST).

Blood red, bright orange, gentle turquoise: it's all good. Mark your calendar in vivid color for the Feb. 20th lunar eclipse.

from http://science.nasa.gov/headlines/y2008 ... list975392

[Brad Reddekopp]

Don't miss this one. It's the last total lunar eclipse until 2010.

Times and diagrams for various parts of the world here: http://sunearth.gsfc.nasa.gov/eclipse/L ... Feb21.html

If you're on the east or west coast of North America:

Partial Eclipse Begins:
08:43 pm [EST] 05:43 pm [PST]

Total Eclipse Begins:
10:01 pm [EST] 07:01 pm [PST]

Mid-Eclipse:
10:26 pm [EST] 07:26 pm [PST]

Total Eclipse Ends:
10:51 pm [EST] 07:51 pm [PST]

Partial Eclipse Ends:
12:09 am [EST] 09:09 pm [PST]

[Brad Reddekopp]

Of course, there is also coverage of this at spaceweather.com -- the have an animated timetable here: http://shadowandsubstance.com/

Go to http://spaceweather.com for more, including links to live webcasts.

[Brad Reddekopp]

High-definition images of the earth from the moon, taken by Japan's KAGUYA project which is currently orbiting the moon. According to the site, these are the first high-def images of Earth-rise and Earth-set.

http://wms.selene.jaxa.jp/index_e.html

[MustangGT]

High-definition images of the earth from the moon, taken by Japan's KAGUYA project which is currently orbiting the moon. According to the site, these are the first high-def images of Earth-rise and Earth-set.

http://wms.selene.jaxa.jp/index_e.html

I see the site, but where are the actual images? I wanna put one as a wallpaper or something.

[Brad Reddekopp]

After the flash loads, look under "What's New" for the link to "The Moon Image by HDTV".

[Brad Reddekopp]

That gets you to the gallery. NASA's web site has a link to one of the images here: http://science.nasa.gov/headlines/y2008 ... /hdtv2.jpg

[Brad Reddekopp]

Space Weather News for July 9, 2008
http://spaceweather.com

JUPITER AT ITS BRIGHTEST: Jupiter reaches maximum brilliance this week, on July 9th, when it makes its closest approach to Earth for all of 2008. At sunset, look low and southeast for a beacon of light brighter than any star. That is Jupiter rising for an all-night transit across the southern sky. During this time of closest approach, Jupiter makes a wonderful target for backyard telescopes. Even small telescopes reveal the planet's cloud belts, its four largest moons, and the Great Red Spot, an anti-cyclone twice as wide as Earth. Just a few days ago, the Great Red Spot ran over a sibling, the Little Red Spot, and may have destroyed the smaller storm. Amateur images of the collision are featured on today's edition of http://spaceweather.com .

[Brad Reddekopp]

The largest known prime number now has 12.9 million digits.

OTTAWA — Carleton University doctoral student Jeff Gilchrist has a thing for numbers.

Working with an international team, Mr. Gilchrist has helped to discover the largest known prime number, at a whopping 12.9 million digits.

The discovery qualifies his team for a $100,000 prize, awarded by the U.S.-based Electronic Frontier Foundation.

This is the first time number crunchers have been able to crack the 10 million digit threshold when identifying prime numbers.

In the mathematics field, “it's sort of like an Olympian breaking a world record,” said Mr. Gilchrist. “It's very exciting.”

To put the number's sheer size in perspective, Mr. Gilchrist said if you were to write every digit down, it would be enough to fill a 3,200-page book.

Full article: http://www.theglobeandmail.com/servlet/ ... m_mostview

Titanic Primes Raced to Win $100,000 Research Award

San Diego CA and Orlando FL, September 15, 2008 – Researchers have discovered the two largest known prime numbers, a whopping 12,978,189 and 11,185,272 digits long, as part of a 12 year old, world-wide volunteer computing project, the Great Internet Mersenne Prime Search ("GIMPS"). The primes can be written shorthand as 243,112,609-1 [Edit: Hmm. I must try to get a superscript modification] and 237,156,667-1. The larger number qualifies for a $100,000 research award, most of which GIMPS will donate to the University of California, Los Angeles (UCLA), and to charity.

Full article: http://mersenne.org/m45and46.htm

[MustangGT]

Interestingly, in terms of numbers, there are still an infinite amount of prime numbers that we haven't yet "discovered."

Infinity is a trippy concept.

[Brad Reddekopp]

If your region isn't in a deep freeze, go stand around outside on Monday night and see if you can see some meteors.

From spaceweather.com:

Space Weather News for Dec. 21, 2008
http://spaceweather.com

URSID METEORS: Earth is passing through a stream of debris from comet 8P/Tuttle and this is causing the annual Ursid meteor shower. Forecasters expect the Ursids to peak on Dec. 22nd with 8 to 10 meteors per hour flying out of the constellation Ursa Minor (the Little Dipper) not far from the north star. The display is usually mild, but outbursts of Ursids occasionally surprise observers with rates many times normal. The last time this happened was in 2006.

Standing outdoors to watch Ursids in December can be a chilling experience. So why not stay inside and listen? Spaceweather.com is broadcasting live audio from the Air Force Space Surveillance Radar in Texas. When a meteor passes over the facility--"ping"--there is an echo. Because the Ursid radiant is circumpolar (always up) over the radar, the echoes may be heard at any hour, night or day. Tune in to http://spaceweather.com to try the audio feed, which can support 1000 simultaneous listeners.

[Brad Reddekopp]

An excerpt from SpaceWeather.com:

The Quadrantid meteor shower is one of the year's best, producing more than 100 meteors per hour from a radiant near the North Star. This year the shower peaks on Jan. 3rd. The timing favors observers in western North America and Across the Pacific Ocean. The best time to look: during the dark hours before sunrise on Saturday morning.

Although the Quadrantids are a major shower, they are seldom observed. One reason is weather. The shower peaks in early January when northern winter is in full swing. Storms and cold tend to keep observers inside. Last year, NASA scientists went to extremes to gain a good view; they flew an airplane above the clouds and over the Arctic Circle where they saw many Quadrantids

Another reason is brevity. The shower doesn't last long, a few hours at most. Even dedicated meteor watchers are likely to miss such a sharp peak. In his classic book Meteor Astronomy, Prof. A.C.B. Lovell lamented that "useful counts of the Quadrantid rate were made in [only] 24 Januaries out of a possible 68 between 1860 and 1927. ... The maximum rate appears to have occurred in 1932 (80 per hour) although the results are influenced by unfavorable weather."

Full article here: http://spaceweather.com/meteors/quadran ... 218b3k4ai3

[Brad Reddekopp]

This Saturday night (Jan 10), we'll see the biggest moon of 2009, up to 14% wider and 30% brighter than it appears to be at other times. Yep, it's that apogee/perigee thing again.

[Brad Reddekopp]

From SpaceWeather.com:

APPROACHING COMET: Comet Lulin (C/2007 N3), discovered in 2007 by a collaborative team of Taiwanese and Chinese astronomers, is swinging around the sun and approaching Earth. The photogenic comet has a bright tail and an "anti-tail" visible in mid-sized backyard telescopes. At closest approach in February, Comet Lulin is expected to brighten to naked-eye visibility. Visit http://Spaceweather.com for sky maps, pictures and more information.

[Brad Reddekopp]

There will be a meteor shower this week -- could be spectacular or it could fizzle.

From the spaceweather.com newsletter:

MORNING METEORS: Earth is entering a stream of debris from Comet Thatcher, the source of the annual Lyrid meteor shower. Forecasters expect the shower to peak on Wednesday, April 22nd, with a display of 10 to 20 meteors per hour over the northern hemisphere. Occasionally, Earth passes through a dense region of the comet's tail and rates surge five- to ten-fold. In 1982, for instance, observers were surprised by an outburst of 90 Lyrids per hour. Because Thatcher's tail has never been mapped in detail, the outbursts are unpredictable and could happen again at any time. The best time to look, no matter where you live, is during the dark hours before dawn on Wednesday morning April 22nd. Visit http://spaceweather.com for full coverage.