Astronomy: The eta Aquarid Meteor Shower

Alpha Monocerotid meteor shower in 1995. Perseid meteor shower, richest shower of the year, peaks in August. Image via Wikipedia

From Denny: You will want to get out of bed early come Wednesday morning to see the meteor showers! You can have your coffee later.

SpaceWeather.com is reporting:

Forecasters expect the 2009 eta Aquarid shower to peak on Wednesday morning, May 6th, with as many as 85 meteors per hour over the southern hemisphere. Sky watchers in Australia, New Zealand, South America and southern Africa are favored. Rates in the northern hemisphere will be less, 20 to 30 per hour. The best time to look is during the moonless hour before local sunrise. That is when the shower's radiant is high in the sky and the nearly-full Moon will have set, leaving the sky dark for meteors.




Sky Map for the Northern Hemisphere

Eta Aquarids are flakes of dust from Halley's Comet, which last visited Earth in 1986. Although the comet is now far away, beyond the orbit of Uranus, it left behind a stream of dust. Earth passes through the stream twice a year in May and October. In May we have the eta Aquarid meteor shower, in October the Orionids. Both are caused by Halley's Comet.

The shower is named after a 4th-magnitude star in the constellation Aquarius. The star has nothing to do with the meteor shower except that, coincidentally, meteors appear to emerge from a point nearby. Eta Aquarii is 156 light years from Earth and 44 times more luminous than the Sun.

The constellation Aquarius does not rise very far above the horizon in the northern hemisphere, and that's why northerners see relatively few meteors. But the ones they do see could be spectacular Earthgrazers.



Sky Map for Southern Hemisphere

Earthgrazers are meteors that skim horizontally through the upper atmosphere. They are slow and dramatic, streaking far across the sky. The best time to look for Earthgrazers is between 2:00 to 2:30 a.m. local time when Aquarius is just peeking above the horizon.

Experienced meteor watchers suggest the following viewing strategy: Dress warmly. Bring a reclining chair, or spread a thick blanket over a flat spot of ground. Lie down and look up somewhat toward the east. Meteors can appear in any part of the sky, although their trails will point back toward Aquarius.

Tidbits:

Eta Aquarid meteoroids hit Earth's atmosphere traveling 66 km/s.

Typical eta Aquarid meteors are as bright as a 3rd magnitude star.

Astronomy: New Signs of Hidden Sea on Saturn Moon

From Cosmic Log at MSNBC.com:

"New research suggests the ice volcanoes blasting off Saturn's moon Enceladus are rooted in an underground sea, a finding that raises the prospect for microbial life.

Scientists have been trying to figure out what is happening on Enceladus to generate the icy geysers that have been photographed, analyzed and sampled by the Saturn-orbiting Cassini spacecraft.

"This debate has been going on for years — whether there has been liquid water, whether there could be an underground ocean," Cassini scientist team member Candice Hansen-Koharcheck told Discovery News.

Astronomers used ground-based telescopes to look for molecules of sodium, which should be present if rock had mingled with liquid water. They didn't find any, silencing proponents making a case for a subsurface sea on Enceladus.
That point is now moot. At a meeting of European geoscientists in Vienna last week, Frank Postberg with Germany's Max Planck Institute for Nuclear Physics and colleagues explained that the sodium is, in fact, there — it was simply bound in a form (sodium chloride) not detectable by Earth-bound telescopes.

"This is only possible if the plume source is liquid water that is or has been in contact with the rocky material of Enceladus' core," the scientists wrote in the EGU General Assembly's 2009 Geophysical Research Abstracts.

Added Carolyn Porco, head of the Cassini imaging team, "Suffice it to say the prospects of a subsurface sea on Enceladus are excellent."

For the rest of this very interesting article just click on the title link. (Jury duty starts today for me - apologies for not being able to re-write this into a condensed form for you!)

Astronomy: Enjoy the Outer Space Circus

From Cosmic Log on MSNBC.com:

"The month of May is bringing in so many outer-space wonders, it's as if a three-ring circus were rolling into town with four or five rings. Today is Space Day, which morphs into Astronomy Day and the Astronaut Hall of Fame on Saturday, followed by the peak of the Eta Aquarid meteor shower next week ... all leading up to one of the greatest shows off Earth, the final upgrade to the Hubble Space Telescope.

And if that still isn't enough rings for you, there's a sparkling new image of a ring galaxy from Hubble's younger sibling, the Spitzer Space Telescope.

Rivers of stars

The fresh infrared view of the spiral galaxy NGC 2841, which is 46 million light-years away in the constellation Ursa Major, figures in recently published research that looks at why stars become so smoothly distributed in such galaxies. After all, stars are created in bursts of clusters, and thus start out their lives in lumps.

"Our analysis now answers the great puzzle," David Block, an astronomer at the University of the Witwatersrand in South Africa, said in a news release issued Thursday by Spitzer's science team. "By finding a myriad of streams of young stars all over the disks of galaxies we studied, we see that the mechanism for pulling the clusters of young stars apart is shearing motions of the parent galaxy. These streams are the 'missing link' we needed to understand how the disks of galaxies evolve to look the way they do."

For much more and an interesting read, just click on the title link. (Didn't have time to re-write this into a smaller read as I have jury duty this week and working hard to load posts for all 9 blogs! Thanks for your patience.)

Brain: The Technology of Mind Reading

Animation of an MRI Brain Scan Image via Wikipedia

From Denny: Published last fall in Nature - and their academic snooze writing decoded by Psychology Today - come most curious findings from an fMRI study of human brain activity. It seems science is on the outside edges of being able to read your mind!

Right now researchers have been able to learn what a subject is looking at as long as it is a photo of a scene in nature. "Using fMRI, the investigators acquired a template response from each subject's visual cortex and then used this template to "decode" the brain's response to novel images," says Psychology Today.

How were the investigators able to decipher to a high degree of accuracy what the subjects were viewing? Using a computer algorithm they scanned the visual cortex of the subject. Basically, it came close to mind reading with a 92% accuracy.

In the experiment all the algorithm was required to do was look at the known brain activity and then proceed to choose from a known set of images to determine which one was the best match. The algorithm did not take the brain activity and then reconstruct what the subject was actually seeing - there is a difference here. If there was a large image library maybe some day the computer just might be able to do this reconstruction process and practically "read minds."

Written by Denny Lyon

Ready Reference: Health News Links and Google Swine Flu World Map

From Denny: Considering how nervous people are getting with the growing negative news about the current (now global) pandemic of the swine flu outbreak, I've started a place of Health News Links and the new Google Swine Flu World Map above the posting area of my health blog, The Healing Waters,for your ready reference so you can stay up to date. As I continue to find more quality reliable news links they will be added.

Photo by Igor Zenin

Weather: Cool Satellite Photo of Washington, D.C. Flowering in the Spring!

From Denny: Popular Science online magazine featured this photo recently. It's from the GeoEye-1 satellite, orbiting at four miles per second, passing over Washington, D.C. during the Cherry Blossom season this April 4th to "admire the view." ;)

The view was shot from the height of 423 miles as the spacecraft moved from north to south along America's eastern seaboard. Along the tidal basin the cherry trees are in full bloom. The huge number of cherry trees were all a gift from Japan to America decades ago.

Washington, D.C. in bloom Image via Wikipedia

Someone left this comment on their site:

"Can anyone tell me the time of day that the image was taken?

The Washington Monument makes a fantastic sundial, it's almost a shame the builders didn't insinuate analematic features into the monument-scape of the Mall."

Now there's an interesting idea!

For a larger view of this satellite photo, go here.

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Brain: Some insight into why it's harder to recognize different-age faces

From Denny: Yesterday on Cognitive Daily I left this comment on their post "Super-recognizers: people with an amazing ability to recognize faces."

"Looks like I got all the faces: X is recognizable by his eyes and that half-sour "I'm uncomfortable" half-smile, Bill Clinton by his cheekbones in relation to his smile, Scarlett recognized by her serious pout and Wayne by his eyes like half-closed (what some people call bedroom eyes) and how he tilts his head.

Actors Jeff and Beau Bridges have that head-tilting characteristic in their body language too. When I saw an actor recently (passing by the TV on my way out) who displayed their same facial expressions and body language but looked very different. I asked my husband if he was related to the Bridges family and he replied, Yeah, that's Jordon Bridges. Some people, especially leaders in any field, develop a distinctive combination of expressions that are unique to them and easy to remember.

Posted by: Denny Lyon | April 27, 2009 5:38 PM"

Some insight into why it's harder to recognize different-age faces

Today's post and link is the follow-up to yesterdays' post about the "super recognizers." The current studies are examining as to why this happens. Mainly, there is still a lot of speculation and even more questions than answers.

Questions on deck:

Are people better at recognizing others of the same race?

Are people better at recognizing others of the same age?

Speculative answers:

Several studies have now revealed that others are better at recognizing those who look like themselves compared to those who are different, meaning same-race and same-age are the strongest factors for recognition. Same-race has been studied the most.

Questions as to what causes this type of recognition:
Are we better at recognizing people we see more often?

Do we have a separate process for recognizing those inside our group as opposed to those outside it?

Are we more adept at recognizing the faces of our loved ones and friends?

Answers from a study of non-teachers and teacher trainees:

In a recent study of non-teachers and teacher trainees they found the trainees were more adept at recognizing the kids' faces. Researchers realized that age-related differences in facial recognition are not due to any inside or outside group preference. Actually, teachers still recognize childrens' faces better than adults of their own age.

Researchers' Speculations

Researchers are postulating that the teachers are more motivated to recognize the kids so that may account for their success as well as constant exposure to that age group makes recognition easier than for others. Researchers are going to study both suggestions to see if one or the other is true - or if both suggestions are contributing factors.

Read that as they think they know why this facial recognition happens but they "will get back to you after it's official" - an official study, that is! :)