Stockton Astronomical Society

Valley Skies - March 2005 Issue

Editor's Corner...

Keep your fingers crossed for clear skies on March 19th. That's the date for this year's big SAS Astronomy Day Star Party at Micke Grove.

OK, so we're jumping the gun a bit - the official Astronomy Day designated by the AANC and the Astronomical League is in April. We tried for that but the Historical Museum grounds are not available for the First Quarter Moon weekend in April. We opted to take a chance on the March weather and set it for March 19. That will be our Astronomy Day.

Last year's star party at Micke Grove was phenomenal, with an orderly and enthusiastic crowd of viewers estimated at 700-800 people, including lots of families. All of us who participated came away elated with the results.

This year will be even bigger and better...provided we have the full support and attendance of as many SAS members as possible. Last year we had 22 telescopes there. This year we're hoping we can have 30 scopes set up. That means everyone who has their own telescope plus a few members who would be willing to keep one of the club's telescopes pointed at the Moon or Saturn or Jupiter.

There will be plenty of other show piece objects in the evening sky, including Mercury, which will set an hour and a quarter after the Sun. We'll still have the Winter constellations high overhead, with the Orion Nebula, the Pleiades, the Hyades Cluster, the Double Cluster in Perseus, and maybe the Andromeda Galaxy for a while.

We also need members without telescopes there to staff an information table, to point out constellations, to direct people, answer questions, and generally provide a strong SAS presence.

In other words, WE NEED YOU, if you can possibly be there.

There are a few members in the club who frequently volunteer their time to provide telescope viewing at school star parties or at Sky Tours. This is an opportunity for the rest of you to pitch in - with or without a telescope - to help with the club's public outreach. I can promise you, you won't regret it.

Remember the first time you saw the Rings of Saturn? Craters on the Moon? Moons of Jupiter? Remember that feeling?

You can be part of sharing that sense of wonder with hundreds of eager visitors to the SAS Astronomy Day Star Party.

This could be the biggest community outreach event we've ever put together. We're counting on you to be part of it. Please be there.

...Trevor Atkinson

Observing:  Messier Marathon

This is the month for the annual Messier Marathon, an event that allows an observer in the Northern Hemisphere to observe all 109 Messier objects in a single night. If a Saturday night - Sunday morning is your only option, the optimum evening this year will be March 12th.

There is a strategy for observing all the Messiers. As the sky revolves about the observer (actually the observer revolving about the center of the Earth), objects set in the west and rise in the east. If you don't catch an object in time, it sets and is out of the game. If you wait too long you will find that there are 15 objects to see with only time to catch 10 of them. So, order matters.

Observing the Messiers in one night usually works best if you clump them into categories. There are four major categories, early setters, mid-evening objects, Virgo cluster, and late risers. There is also a lull where the observer will have cleared the sky out and must wait for objects to rise. This is used as nap-time by many. I don't like to because awakening is a horrible thing. One way to beat that game is to incorporate a Herschel hunt into the night, or planetary viewing, or some other specialty hit list.

One of my favorite goals is to do a Messier/Herschel marathon, a very cruel but rewarding experience. At the March 10 meeting I will have the Messier/Herschel hit list. Even if you don't plan on observing all these dudes in one night, it's a good list to have in your astro kit for recreational viewing.

Back to the Messier Marathon. I have the Messiers grouped into an order that will allow you to nail the early setters first and progress your way across the sky. Furthermore, they are grouped into regions. You can nail all the objects in a region, take a breather, then start up on the next region. Repeat until finished.

Here are other strategies to think about. PLAN AHEAD. You should have a checklist to follow and mark off objects as you clobber them. Coordinates, star hop charts, etc. should all be ready before sunset so you don't have to hunt around in the dark for stuff that should already be there for you. Your site ought to be Messier Marathon friendly, low horizons in the west and the east. The south isn't such a big deal here in California, the lowest Messier transit is still 22° high. You should have a site that doesn't have killer lights, some of the Messiers have low surface brightness. Have a thermos of warm drink, some food and candy, some toilet paper and a good spot for using it, and hopefully some good friends to share in the experience. Have your charts ready, in order, and do a practice chart check once or twice before the event so you are familiar with your sweep strategy. You may also want to do a checklist of equipment and charts before leaving the house for the site.

Warning, M30 is the toughest of them all. It rises in virtual daylight. I've never gotten all 109, my best is 108, the whole list minus M30. That little booger. I've observed with liars that told me they got it, but when I've gone to their eyepiece I've only seen blue sky. One of these days I'll get it and I'll be "The Liar". Actually, I'm sure they've gotten it, I'm just using loser engineering, blaming my loss as others' lies.

Finally, be careful coming home afterward. You will be exhausted beyond your wildest dreams. You will be home in bed dreaming about golfing in Carmel, with a deer walking across the green, and suddenly, WHAM!...you're in a car wreck! You weren't home in bed sleeping, you were driving. Yikes!

OK, here's the list broken down into groups. I'll have their coordinates printed at the meeting, or you can e-mail me and I'll send them to you. Oh, remember, if you are going for an observing certificate, you must find them all without the aid of electronic devices, like GOTO telescopes and digital circles. Use mechanical circles and star hopping, that's the ticket. If you're not going for the certificate, who cares, have fun! That's what it's all about, isn't it?

Before Full Dark	45
Early Setters	74, 77
Right after full dark	33, 31, 32, 110
Group 4	76, 34, 103, 52
Group 5	42, 43, 78, 79, 41, 93, 47, 46, 50, 48
Group 6	1, 35, 37, 36, 38
Group 7	44, 67
Group 8	81, 82, 97, 108, 109, 106, 94, 63, 51, 101, 40
	For those who consider NGC 5866 as M102, this is the time to get it. I don't consider this a Messier object.
Group 9	95, 96, 105, 65, 66
Group 10	98, 99, 100, 85, 88, 91, 84, 86, 87, 89, 90, 58, 59, 60
Group 11	49, 61, 104, 68, 83
Group 12	64, 53, 3, 13, 92, 57, 56, 27, 71, 29, 39
Group 13	5, 12, 10, 14, 107, 9, 80, 4, 19, 62, 6, 7
Group 14	11, 26, 16, 17, 18, 25, 24, 23, 21, 20, 8, 28, 22, 69, 70, 54, 55
Group 15	75, 2, 15
Dawn Risers	72, 73, 30

Happy Hunting!...Jeff Baldwin

The Science Directorate at NASA's Marshall Space Flight Center sponsors the Science@NASA web sites. The mission of Science@NASA is to help the public understand how exciting NASA research is and to help NASA scientists fulfill their outreach responsibilities.

Ultrasound for Astronauts

By Karen Miller & Dr. Tony Phillips

Far away from doctors and hospitals, astronauts in space are learning to give themselves checkups using ultrasound.

February 16, 2005:  When you hear the word "ultrasound" you probably think of pregnant moms and their babies. Add one more to that list: astronauts.

Nobody's pregnant in space, but astronauts onboard the International Space Station (ISS) are using ultrasound, looking inside themselves as part of a NASA project called ADUM, short for "ADvanced Ultrasound in Microgravity."

On board the International Space Station, Gennady Palalka performs an ultrasound exam on Mike Fincke.

Dr. Scott Dulchavsky, a surgeon at the Henry Ford Hospital in Detroit, heads the project. His team, which includes co-investigators Doug Hamilton, Shannon Melton and Ashot Sargsyan of Wyle Laboratories in Houston, is studying how ultrasound can be used to diagnose medical problems onboard spaceships. Here on Earth, doctors can look at broken bones with an x-ray machine, they can look for tumors with a CAT scanner, and they can examine your brain with an MRI. None of those bulky instruments is available on any NASA spacecraft.

There is, however, an ultrasound machine on board the ISS. Ultrasound offers several advantages: Compared to other diagnostic imaging tools, ultrasound machines are compact and lightweight. This is important on cramped spaceships where every ounce of payload costs money to launch. Furthermore, ultrasound images appear instantly. You don't have to wait for, say, x-ray films to be developed. Got a problem? Ultrasound can find it quickly. An ultrasound probe works somewhat like radar. It sends high-frequency (megahertz) sound waves into the body. When those waves encounter an organ-say, the liver-some bounce back immediately, and some continue, bouncing back when they reach the next organ-say, the kidney. Because sound waves travel through each organ, or tissue, at a different speed, the probe is able to "see" what the reflected sound waves have found. Typically, ultrasound has been used to look at internal organs. It's often used to examine fetuses. But Dulchavsky and his team have been expanding its repertoire. They're working out ways to look at eyes, teeth, lungs, bones and muscles. They believe that ultrasound can be used for about two-thirds of a list of approximately 500 medical conditions that might hypothetically occur on a spacecraft. And, in some cases, ultrasound works even better in space than it does on Earth. That's because in low gravity, internal organs move around. "The heart shifts up. ...The liver moves about three inches north." The result is that organs often end up closer to each other. That's good. Sound waves move from one to the other with less distortion, providing a clearer ultrasound picture.

An ultrasound view of ISS astronaut Mike Fincke's biceps tendon. "D" denotes the deltoid muscle. "T" is the proximal intracapsular end of the long biceps tendon.

Traditionally, ultrasound probes are operated by technicians with several hundred hours of training. Astronauts only get about four hours training. How do they manage? "We're helping them," says Dulchavsky. As the astronauts work the probe, they're in constant contact with experts on the ground. Recently, the procedure was tested with ISS astronauts Mike Fincke and Gennady Padalka. The ground crew and the astronauts relied on a satellite downlink to share information." [Mike] puts the probe to the skin, and then, two seconds later we in the Johnson Space Center get to see the same image he sees," says Dulchavsky. It's an interactive process: "We go, 'Mike, that's not quite right. Can you move the probe an inch closer to the elbow?' So, Mike slides it down an inch closer. 'Ah, that's really good, you need to push harder.' Mike pushes harder. 'Almost perfect, move it half-an-inch to the back. Ahh, you've got it. Perfect!'" This technique, non-doctors using ultrasound to obtain diagnostic quality pictures under the guidance of remote experts, turns out to have important applications on Earth-on battlefields, for instance, or in rural areas where doctors are far away. "We're looking at modifying how we transmit the information, so we could do it through a cellphone," says Dulchavsky. Picture this: "we could put ultrasound probes on ambulances." Emergency room doctors could set up a treatment before the patient even arrives at the hospital. The process has already been used successfully on the ground-in the locker room of the Red Wings, Detroit's hockey team. "Players get hurt a lot in NHL games," says Dulchavsky, a fan. "Last season, we trained one of their trainers to use the probe. It worked famously."

Dr. Scott Dulchavsky (far right) shows Detroit Red Wings trainer Piet Van Zant (far left) how to use an ultrasound machine.

It works well in space, too. In the ISS experiment, Fincke and Padalka examined each others' shoulders. That joint was picked, says Dulchavsky, because it's so complicated. And, even though the shoulder is one of the most challenging ultrasound examinations to do, the astronauts were able to obtain clear, diagnostic-quality views. A paper describing the procedure was published in the February issue of the journal Radiology; it's the first article ever submitted from orbit. Right now, Dulchavsky and his colleagues are analyzing their data. The next step, he says, is to put together a program that will teach the astronauts to do more and more on their own. This would enable ultrasound to be used even on long-range exploration missions, like trips to Mars, where guidance from the ground is less practical. The ADUM project is significant, says Dulchavsky, because it has pushed the limits of what ultrasound technology can do. He and his colleagues plan to push those boundaries even more.

A Different Angle on Climate Change

by Patrick L. Barry

Look toward the horizon in almost any major city, and you'll clearly see the gray-brown layer of smog and air pollution. Yet when you look straight up, the sky can appear perfectly blue; you might think there's no smog at all!

The smog is overhead as well, but it's much harder to see. Why is there such a difference? It comes down to viewing angles: A vertical line straight up through the atmosphere crosses much less air than a line angled toward the horizon. Less air means less smog, so the sky overhead looks blue. On the other hand, when you look toward the horizon, you're looking through a lot more air. The smog is easier to see.

The MISR instrument on the Terra satellite views the atmosphere and Earth's surface from nine different angles.

A one-of-a-kind sensor aboard NASA's Terra satellite capitalizes on this angle effect to get a better view of how clouds and air pollutants scatter and absorb sunlight. By doing so, this sensor-called the Multi-angle Imaging SpectroRadiometer (MISR for short)-is helping scientists fill in a major piece of the climate change puzzle.

Most satellite instruments look only straight down at the Earth. Layers of airborne particles (called aerosols) and smog are harder to see with this vertical view, and clouds often appear only as two-dimensional sheets of white. Clouds and aerosols both can reflect incoming sunlight back out to space, thus cooling the planet. But they can also absorb sunlight and trap heat rising from below, thus helping warm the planet.

What is the net effect? MISR helps scientists figure this out by looking at the atmosphere at several angles-nine to be exact. Its nine cameras fan out across a range of angles from steeply looking forward (70.5 degrees from vertical), to straight down, to the same steep angle backwards. As the Terra satellite passes over a region, the cameras successively view the region at nine different angles.

From these data, scientists can construct a three-dimensional picture of the cloud cover, revealing much more about cloud dynamics than a flat image alone. They can also see light bouncing off aerosol pollution from nine different directions, thus getting a fuller picture of how aerosols scatter sunlight. And they can even spot thin layers of heat-trapping air pollutants that might go unnoticed by other satellites.

All this information comes just from looking at the atmosphere from a different angle.

For more information, see http://www-misr.jpl.nasa.gov. Kids can learn about MISR, see MISR images, and do an online MISR crossword at http://spaceplace.nasa.gov/en/kids/misr_xword/misr_xword2.shtml.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Copyright © 2005 by Stockton Astronomical Society
Last Updated: 3/7/2005
http://astro.sci.uop.edu/~sas/Newsletter/VS0503.html