This Issue Contains
Notice of Excellent Childrens' Astronomy Book on Sale
Notice of Upcoming PBS Special About Observing the Sky
Announcements About Circulation, Outreach, and Instructors
How to Visit Pine Mountain Observatory With Your Class
Update on Status of Instruments at Pine Mountain Observatory
Observations About the Recent Lunar Eclipse-Moon's Motions
How Do We Know That? Inquiry Strategies
Basic Earth-In-Space Curricula Topics
"Sun Stake" Project Illustrating Sun-Earth Relationship
Hollywood Compounds the Difficulty of Teaching Science and Math
Eye on the Sky - What to Observe in the Real Sky
How Big Can a Star Be?
Resources Online and Otherwise
NASA Participation Opportunities for Students and Teachers
OSTA Conference in Milwaukie in October
Our policy is not to offer advertisements, but this is a significant resource for your classroom: Excellent current astronomy book now on sale at BORDERS bookstores! Children's Atlas of the Universe by Robert Burnham published by Fog City Press, 2007 2nd edition. Bargain Book, now on sale for $5.99! (-further discount if you're a teacher!) It's large format, book is about 14x12 inches with nice image of Ring Nebula in color on cover. Has sky charts and info about observing the sky, plus a lot of current info about Earth in Space, Solar System, Galaxy, and Cosmology. Features Hubble Deep Field as front and rear inside lining. Very nice, if you're a K-6 teacher, try to get one of these for your classroom, I highly recommend this book! Rick
Confirm your local television program listings for the broadcast date and time for Seeing in the Dark, a new special put together by noted astronomy writer, Dr. Tim Ferris. Initial information indicates Wednesday, September 19th, at 800 PM. The program is reported to cover viewing the sky from an amateur astronomer's viewpoint, the "rewards of first-person, hands-on astronomy".
There is an associated website, http://www.pbs.org/seeinginthedark/ is the initial URL, officially goes online September 5th, that has more details about the program and also a variety of interactive features.
Welcome back, hope you had a great summer!
We're here to help you implement even better teaching strategies for your unit about Space Science, don't hesitate to contact us!
During the summer we conducted two North Coast Teachers Touching the Sky sessions at Pine Mountain and a special Photometry Sky Imaging Session with Richard Berry. Attendees from these sessions are great resource contacts for you, we can put you in touch with them. (We anticipate future similar sessions, stay tuned to the IMAGE/FOPMO Website for info.)
As with prior years, due to the extremely abbreviated format of the hard copy IMAGE, we'll feature the full articles, several additional articles, and web URLs on this electronic version, so be sure to check in here if you need all the details from an article or topic mentioned in the one page hard copy version of the IMAGE or are searching for additional items about space.
Updating our Subscriber List, How to Subscribe to the IMAGE:
We're working on gathering information to make our list as current as possible, we realize that some of you have moved/retired/changed subjects:
Monica Geraths, a professional graphics artist who volunteers as a classroom aid at an elementary school in Portland, is beginning to work with me on a variety of administrative issues. One of her goals is to improve and expand the outreach program by delivering information about the program to schools throughout Oregon. One of the portions of that job is to update the mailing list for the IMAGE. You or your office or district staff may hear from Monica in the Fall as she seeks current mailing information and wants to let you know about our program. If you're retiring or moving and want to update your mailing label, please contact Monica at firstname.lastname@example.org or at 503-757-3209.
Monica just designed a way cool very informative brochure about the outreach program, we'll be mailing these out, and posting a copy online, don't hesitate to direct your colleagues to this document.
If you wish, we can e-mail either the short or the full version of the IMAGE to you, again, please let Monica know if you'd like this service, several years ago we were e-mailing to about 20 teachers but slowly the database eroded as people switched ISPs.
We're redirecting the emphasis of our outreach program just a bit: the prime thrust will be to address the basic science inquiry question: How Do You Know That? We want to help you bring data driven investigations of Space Science topics into your classroom by modeling inquiry based programs for you. For example, you or your students might ask how do we know the Moon orbits Earth, how do we know that we receive more sunlight during summer, or how we know the temperature of a distant star. We will lead you and your class through collection and analysis of data that addresses your selected topic. The ultimate goal is facilitate your comfort to deliver such programs on your own to your students. We will continue to offer our subject matter expertise, resources to show your students the latest data (primarily Internet sources), and access to technologies such as telescopes and CCD Cameras to intrigue your students as well as supply them with data. The big push is to really promote the idea of doing science, aka using and critically analyzing unbiased data to make discoveries. You can think of our visit to your classroom as an extension of one of our North Coast Teachers' inquiry sessions where you can gain all the advantages from that plus have us directly work with your students.
Speaking of which, I should introduce four of our potential additional outreach instructors for this schoolyear:
Kent Fairfield lives in LaPine and came to us from a docent position at Lick Observatory near San Jose, California. Kent has been with the Pine Mountain operation for several years now and is an instructor for the North Coast Teachers over the past three summers. His extensive technical knowledge and background, plus his familiarity with the sky makes him a great resource.
Greg Hogue lives in Bend and is the Visitors' Program Chairman for Pine Mountain Observatory. An avid "deep sky" observer, connoisseur of galaxies billions of light years from Earth, his enthusiasm and knowledge about the sky brightens the interest of many visitors to Pine Mountain.
Bob Ewing lives in Portland and is trying to retire from the Portland Community College system where he's taught Astronomy and Geology for many years. He's served as Vice President of Friends of Pine Mountain for the past four years and continues in high demand to teach Astronomy sections at PCC Rock Creek. Bob has experience in photometry of stars and with the sky and telescopes, he's ready to visit your class to share a variety of skills and knowledge about space.
Mary Hill lives a few miles east of Astoria, where she wields a large telescope skyward from her homesite whenever she's not tutoring math at Clatsop Community College and whenever the clouds part. Mary has been the President of Friends of PMO the past eight years and with her husband, Dave, have been frequent tourguides at Pine Mountain over the past two decades. Mary has visited local schools on occasion and we may invite her to increase her visits now that she's finally found someone else to succeed her as FOPMO President.
We invite anyone else with sky and classroom experience to apply to be an outreach instructor for Friends of Pine Mountain Observatory. This is still volunteer work at this point, you may need to work with the school you visit to supply travel expenses. The job requirements are very challenging: having current astrophysics and sky knowledge, being familiar with State education standards, being familiar with the Scientific Inquiry strategy, knowing how to translate and interpret complex information for a variety of grades/levels, being a classroom facilitator of an investigation and not the apparent source of knowledge, working with a variety of children of all ages, and being on the road a lot. The reward is seeing and sensing the lights coming on as students gain understanding of how science works and how they can actually figure something out themselves, not to mention those students who say they are interested in pursuing a career in science or better yet, space science!
Bring your class to Pine Mountain Observatory: We can host your group for an evening of sky viewing and your group can camp out in the adjacent Forest Service primitive campground. Please make a reservation for your Observatory Visit with Mark Dunaway, email@example.com, 541-382-8331, try to select an evening away from Full Moon, and have a backup evening in case the weather is cloudy. When you contact Mark he can quote you prices.
Here is some information directly from Mark who is the on-site Observatory Manager and the Tour Scheduler:
"Dates to probably avoid: Deer hunting season this year is October 2nd through the 13th. This is an odd time for hunting season, running Tuesday the 2nd through Saturday the 13th of October.
The other thing to keep in mind is that Kent will be gone from Oct 1 through the 15th. This will leave Greg Hogue as the only tour guide during that time.
School tour fees are $100 for the first 1-20 visitors...staff included and $5 per head over 20. So for example, if there are 33 people coming to visit the cost would be $100 for the first 20 and $5 X 13 = $65 for a total of $165.
Have teachers call for available dates. At this point I'd not run tours from the 1st through the 9th of October due to the amount of hunters who will be running round the mountain. The final days of the hunting season are not usually as potentially troublesome, most of the hunters depart back to the valley by Tuesday the 9th of October. The 8th is Columbus day so most of them will be returning to work on Wednesday the 10th.
Please be sure that everyone understands that tour season ends October 31st for sure, and that we'll reopen in the Spring as soon as the snow recedes so that the road is safely passable, usually sometime in April. Schools are welcome to book tours this Fall for the Spring."
Remember to warn your students to bring warm clothing as altitude is over 6000 feet so we'll probably be below freezing by September after dark. Many students are deceived by the warm weather at lower elevations in Bend or Sisters and then retreat in extreme discomfort when they neglect to bring socks, boots, gloves, hats, and sufficient layers of coats to Pine Mountain. Small flashlights are also recommended, with red cellophane covering to protect night vision, we highly discourage use of any white lights or other bright lights. Students should bring a bottle of water and perhaps a snack if the group plans to stay late, we don't have a lot of creature comforts onsite, and the environment is basically outdoors on the mountainside. We do supply free sky charts.
Our TourGuides may present a formal program inside one of the larger domes (this can be arranged in advance) and spend most of the time showing visitors specific planets, star clusters, nebulas, and galaxies through a variety of telescopes outdoors or sometimes in one of the domes (see below about telescope status). Constellation identification and general sky orientation can also be a part of the program, let us know what features you'd like.
We usually have snow on the road by November so we're closed until April or May.
If you're seeking a sheltered place to stay, you might contact the Bend School District, they've provided "campout" space in several gyms for a few groups over the years.
One other idea about visiting PMO, particularly with a small group of colleagues, you can "rent" the Observatory for a flat fee of $100 for the whole evening, includes services of a Sky Tourguide, and free sky maps, again contact Mark Dunaway to make the reservation and for other details.
32" Research Telescope: Telescope electronics and mechanical guru, Mr. Dan Gray, of Portland, worked a miracle with the 32" drive system during the summer, resulting in a much more stable tracking rate and much more accurate pointing. Onsite Telescope Manager, Allan Chambers, is still doing some final adjustments with the rebuilt COWCAM 1kX1k CCD array. This telescope should be able to acquire data for you as long as the weather holds (we don't do any visual observing through this as the optical path sends the light directly into the camera). Please submit data requests with sufficient lead time aka months in advance if possible!
24" Telescope: This telescope that's been our workhorse through the years now suffers from a variety of mechanical ills that fairly frequently disables its tracking capability. We fixed the RA dial problem from last year, but the tracking failure incidents sometimes mean that that telescope is not suitable for visual use and severely restricts imaging with the PIGGYCAM. So, when you visit, we hope to show you some objects through this instrument, but we may run into problems. You can also make data requests from the PIGGYCAM.
15" Telescope: This telescope has been dismounted and stored, pending future museum construction and possible remounting. The dome will be used for our new, automated, 14" research telescope that is awaiting installation of upper pier and mounting mechanism.
The 14", on a Paramount (precision electronic controllable) mount, will feature a very high quality Apogee CCD Camera. Our goal will be to offer this instrument as a data collection source to students and teachers around the world, in automated mode. We don't have a firm timeline yet, as there are several stages to this project and we've just accomplished the first part of the first step. We are looking for funding for filters for the camera and for some of the auxiliary mechanical and electronic devices to complete the hardware/software. We hope to begin test mechanical operation of the new telescope on its mount before the snow flies. This telescope may be offered as a visual observing instrument for visitors next Spring as the CCD is brought online.
As far as downloading images from any of our cameras, Professor Bothun has mentioned that Timbuktu software will be restored shortly, we'll keep you posted. During the summer programs most of the teachers took data home on thumb drives. We can always burn CDs for you.
Tour Manager Greg Hogue usually has his Obsession Telescope (truss assembly Newtonian reflector) set up outside, this features an 18" mirror and offers the best actual visual views of objects of any of the telescopes at PMO. Greg can rapidly move the telescope to an object in a clear patch of sky if there are some clouds, and can quickly go to specific objects that viewers ask to see.
Often other visiting amateur astronomers will have their portable telescopes set up along with Greg's, so we usually have two or three instruments outside on the "upper deck" viewing a variety of targets.
We also have our giant binoculars, Dave Davis of Toledo is working on a new mounting system so that visitors can more readily make use of this instrument that offers an opportunity to sweep through the Milky Way and view lots of star clusters and nebulas.
So, even though the original "domed" telescopes may not be available to use for actual viewing, we have a variety of other instruments some of which actually show you better views than the original three!
Observations on the Recent Lunar Eclipse
Does the Moon orbit the Earth? Which objects orbit the Sun? Which way might the Moon be moving?
Many students (and adults) falter when asked to sketch a diagram of Sun, Earth, and Moon showing relative positions and motions, and many of us can get easily confused when we try to envision the results of possible motions!
OK, what did I observe several nights ago (August 28th, 2007, and over many nights prior)?
- First, I noticed that the Moon appears roughly a palmwidth to the LEFT of where it was the previous night, on successive nights AT THE SAME HOUR (TIME).
- If I plot the positions of the Moon on a drawing that includes the horizon and some reference features along the horizon, I can clearly see this progression.
- The time selected can be evening, middle of the night, or morning (yes, the Moon is visible during a lot of daylight time, look for it!)
Does this progression repeat? Sure, once each "Moonth", about 29 and a half days, just over 4 weeks. What does this tell me? If I restrict my daily observation to the same hour, that means I'm very close to the same angle from my observing location on Earth to where the Sun is in the sky (remember, we tell time by the position of the Sun), so I've effectively "locked" the Earth into one position relative to the Sun, canceling out the Earth's ROTATION!
So, if the Moon appears to slowly wander to the east (left) in the sky each day I observe it, and disappears, and reappears moonthly, maybe the Moon is in an orbit around the Earth. Which way does it move? Our observations show from RIGHT to LEFT, which is from WEST to EAST. Perhaps some day/night at the appointed observation time, when the Moon has disappeared somewhere into the eastern sky, I could contact someone I know who lives far east of me (maybe even half way around the Earth from me), and they could tell me if they can see the Moon, what do you think they'll report? (Just think about this one moment, not the ongoing changes or phases, you'll thoroughly confuse yourself!)
Now, here's the really confusing thing I observed about the Eclipse (technically where one
body in space passes within the shadow of another body) the other night:
As I watched the Eclipse progress (the Moon appeared to slip into a shadow, the sunlight hitting the Moon was severely reduced, leaving only the filtered red light illuminating the Moon, eventually no direct whitish sunlight at all), the Moon appeared to "fall" to the RIGHT, to the west as time went by, although the Moon appeared to enter the shadow toward the LEFT, the east, the shadow crept across the Moon's face from LEFT to RIGHT! What's going on?
Another confusing and dramatic piece of the evidence was as I watched the Moon from my backyard where there are some massive fir trees, I witnessed a Tree Occultation of the Moon (not a Tree Eclipse, remember, an Eclipse is passing through the shadow whereas an Occultation is passing behind, not necessarily through the shadow): I was sitting in a chair at a window, watching the Moon through a pair of small binoculars, I did NOT vary my observing postion/location. The Moon appeared to approach the tree moving left to right, soon the curved leading edge of the Moon disappeared behind the left side of the tree, then more and more of the Moon. Eventually the entire Moon disappeared, to reappear slowly a few minutes later extending outward from the right edge of the tree. Eventually the whole Moon escaped the occultation, what was intriguing was to watch the actual motion of the Moon slowly being devoured and then magically reappearing. What was I really seeing evidence of, what sensation could I experience? (No, not the infamous Sherlock Holmes joke about "someone stole our tent"! (Sherlock first points out to Watson all the stars visible overhead and asks Watson to explain what he sees, Watson waxes on about all the science that's evident until Sherlock points out the obvious...))
But wait, we just concluded that the Moon orbited Earth from west to east, the Moon should show motion to its LEFT, not its RIGHT! What were we seeing?
Let's summarize: Moonthly evidence showed that the Moon appears to move to the LEFT, night by night. Hourly evidence showed that the Moon appears to move to the RIGHT, and fairly rapidly. Shadow evidence showed that the Moon appears to move to the LEFT. What the heck is going on? See if you can sort this out, I'll conclude this article further down in the IMAGE!
Silly Moon, Conclusion
OK, have you figured out the apparent contradictory observed motions of our Moon?
First Observation: Moon appears to shift slightly eastward (to the LEFT) each night, reappearing moonthly. This must be evidence of the ORBIT of the Moon around the Earth.
Second Obervation: relatively rapid motion to the RIGHT, westward, the Tree Occulation: Heck, the stars do that too, as does the Sun, everthing else far away in the sky! You could be a fan of Aristotle and postulate that we live within a rotating Crystalline Sphere, or you might prefer the idea that the Earth spins around it's axis causing the illusion of the constantly changing sky, rising and setting objects, but the evidence at first glance could go either way! If the Earth ROTATES west to east, the Moon, Sun, Stars, Planets, etc., should appear to move east to west as the minutes and hours go by.
Third Observation: Moon moves through eclipse shadow RIGHT to LEFT:
Remember, a Lunar Eclipse is where the Moon is in Earth's shadow, the Moon would need to be
behind the Earth relative to the Sun, sequence is Sun, Earth, Moon. Model the Earth casting a
shadow. Add the Moon model, experiment how to generate a model where the Earth's shadow first
contacts the Moon on the Moon's LEFT side. (Rotating the Earth DOESN'T change Earth's relative
shadow position! Move the Moon, not the Earth!)
The Moon needs to move from RIGHT to LEFT, hey that sounds familiar...that's what the Moon is constantly doing as it ORBITS the Earth.
Now let's put this all together:
The Earth casts a shadow "cone" out into space behind the Earth relative to the Sun. The Moon is orbiting the Earth moving from West to East, so would encounter Earth's shadow on Moon's LEFT or EAST side, and move through, with shadow disappearing at Moon's RIGHT or WEST side as all observers saw.
But, as all this is happening over several hours, the Earth has also been ROTATING, West to East, causing everything in our sky to appear to move East to West, the Tree Occultation and the Moon sinking toward the Western Sky.
Model this with your fists: The key idea is the fist you use for Earth rotates rapidly in
relationship to the speed your Moon fist is moving AROUND the Earth fist!!! Your Earth fist
spins 29 times each time your Moon fist makes ONE orbit!
Now use your head (Mount Nose) for Earth, keep one fist for Moon: Turn your head to the LEFT fairly quickly, keep your right fist (Moon) moving slowly to the LEFT, see how your Moon fist "sets" to the RIGHT, yet moves to the LEFT against the background (stars, Earth's shadow cone). Now expand your model to two students, one being Earth, the other the Moon.
This may be very confusing at first, but the light will dawn! You can test this on subsequent nights, just watch the Moon for a few minutes, try to find a few surrounding stars (best to try when Moon isn't Full). Which way doe the Moon appear to move relative to trees and buildings? Which way doe the Moon appear to move against the background stars? Does this make sense now?
Scientific Inquiry is the "buzzword" for science instruction. Inquiry causes lots of consternation and confusion, seemingly is very ambiguous.
Leading science educators such as Dr. Edith Gummer, Dr. Greg Bothun, and Dr. Kevin Carr try to defuse this confusion by simply having us ask, "How Do We Know That", when confronted by an observation. Greg is also a professional astrophysicist, he spends a lot of his astrophysics time asking the same key question. That's what real scientists do: They or someone else observes a phenomenon, and somebody comes up with a possible explanation. Then the scientific community asks the question. The investigation generally consists of determining the methods to collect data, the actual data collection, measurement, analysis, and display, and then the interpretation, accounting for imprecision in the measurements. Greg always emphasizes the importance of "unbiased" data: there's much more interest and authenticity when students get to examine a set of data that arrives independent of context, so that the focus is on the nature of the data itself, particularly correlations that appear when the data is analyzed. An example that Kevin uses is the "Tube of Science" (a plastic pipe capped at both ends with four strings sticking out from the body... the observer manipulates the device to determine it's interior construction). Greg notes that when we're faced with a discrepancy in our data, we have three choices: ignore the discrepancy (if we can't see it, it doesn't exist), modify our explanation to incorporate the data, or come up with an entirely new explanation. He's been doing a recent talk about the evolution of cosmology in this sense, particularly the need to establish entirely new paradigms as our observations (and technologies) improve. The "noise" in the data is another topic commonly pointed out by Greg: a lot of data is imprecise, usually containing lots of contamination and statistical randomness.
Can we replicate these processes in the classroom? Sure, there are lots of observations and
tentative conclusions available to your students, have them ask the "how do we know that"
question, and start the investigative process, now we're doing inquiry!
Or, start with some data, even just a set of pairs of numbers, and have students graph the pairs and try to look for correlations, there's a relatively new piece of software available, called InspireData, that makes this process easier and does a nice job with the graphics, and is designed to show correlations graphically.
(details at http://www.inspiration.com/productinfo/inspiredata/index.cfm)
We're glad to help you with this process and are ourselves in the process of moving our programs even further toward the Inquiry mode!
The State curriculum standards have remained fairly basic over the past several years:
- Lower grades are required to know about the Rotation and Revolution of Earth and how those motions help us keep track of time, and how Rotation is related to apparent motions of objects in sky.
- Lunar phases, motion, and Eclipses come next on the curriculum, the relationships of Sun, Moon, and Earth.
- Some districts include nature of the Solar System as required topic, and the Sun has its own series of curriculum items, mostly as an energy source.
- Reason for seasons is the only other major Earth-in-Space topic required, and unfortunately causes much confusion (longer/shorter exposure to sunlight is the prime cause, the Earth's tilt causes this, thus is the secondary cause).
- High school level does mention the topic of Gravity as a force.
Most of the other really interesting astrophysics topics are not directly addressed by the State curriculum guidelines, although teachers can readily bring in nuclear reactions, stellar evolution, planetary geology, chemistry, and biology, and cosmology into many other science and math specific topic items.
And, as discussed above, astrophysics is rich with examples that can be used as Inquiry exercises.
We can help you do this, and offer a variety of outreach programs and many resources to facilitate teaching of these topics.
Here is a project for all grade levels, but that should be initiated ASAP to avoid inclement
Set up a "Sun Stake": Place a stake, approximately 12-24 inches tall (or taller), safely, at a permanent location in your schoolyard, where the Sun will cast a full shadow of the stake onto the ground, at the same time, like at 12 Noon, each day. Set up with a plumb line or level so that the stake is as perpendicular to the level ground as possible (pointing straight upward toward its zenith). You could set up a mount for your stake so that it can be taken down when not in use, but readily reset precisely (must be in exactly the same place and position subsequent days so probably better to set it permanently if you can!). You may already have an item like a flagpole or tetherball pole already in place!
The next materials you need will be markers for the SHADOW TIP, that you can leave on the ground that nobody will disturb, you might consider small wedges, dowels, straws, or paint (ask if you can paint there, though!).
Here's the plan: Mark the shadow tip on the ground at the SAME TIME each day, like at local
PREDICT what you think might happen as weeks go by. Carefully label your daily mark so that you can keep track of what is going on. You can also try to predict how the shadow tip will change as HOURS go by, try marking the shadow tip at two or three different hours each day.
What does the SHADOW TIP location tell you about the Sun? If the tip is more toward the pole base or further from the base, where must the Sun be in the sky relative to the prior measurement? If the shadow tip is more toward one side or the other, which way has the Sun appeared to move?
Can you figure out what basic instrument was built by ancient peoples the same way your
instrument is constructed and works?
But wait, we're not only concerned with the change over hours, we want to examine the change over weeks and months. We'll try to follow this project through the year.
Here's another twist: What if your school is in Australia, New Zealand, South Africa, or South America, somewhere in the Southern Hemisphere? Which way would the shadow point, and how would it change? We have an opportunity to pair up with a school in New Zealand, courtesy of an outreach colleague down there, Mr. Eric Jackson, inventor of the PipeHenge model of the sky. You can see Eric and his gadget at his website, http://www.pipehenge.com/new/index.html.
Please e-mail me if your school would be interested in sharing a daily data point with a school "down under"!
Please use the new game show, "Power of 10", as a teachable moment to show your students how
seriously everyone doesn't understand numerical answers!
The show has a lot of potential but then collapses into garbage. Why? Sure, Drew Carey may be a popular comedian, but the principal of the show is undoing everything we're trying to demonstrate to students about how scientific data works: There are no "correct" nor "right" answers!!! The "answers" are statistical quantities, with accompanying uncertainties. Data is accompanied by "noise", always has at least some uncertainty, that's the way nature is. The show purports to use a graphical display of audience response, and a graphical display of range in contestants' answers, good so far, if someone who had a clue actually explained what was being shown, but from there on out, "and now, the answer is..." is the downturning point! Your students need to realize the effect of statistical distribution, just have them measure how wide their desks are, then compile and share the data. (also alert them that the correct expression is Powers, not Power of 10). Could have been a golden opportunity to teach some really essential science and math, but ends up throwing yet another monkey wrench at the students!
Jupiter closes out its 2007 apparition, hanging bright and low in the SW evening post sunset sky through October. This is a great target for observations if your school has access to even a small telescope: The best project is to have students map the orientation of the four Galilean moons at a given hour each night over a week or two, then try to make predictions, and for advanced math students, to try to derive Kepler's law relating major axis to orbital period.
You may notice an "extra" jovian moon the first week or two of September if you're keeping an eye on Jupiter, but this "moon" will steadily shift to the left of Jupiter and eventually leave the jovian zone. This dot is the asteroid, Vesta, far in the foreground, closest superimposing approach to Jupiter was August 29th.
Professor Bothun has a JAVA applet that can let you simulate the motions of Jupiter's moons, see http://zebu.uoregon.edu/disted/ph121/orbits.html
Most of the Planets are visible in the predawn sky, except for Mercury which stays quite close to the Sun's location in the sky and Mercury's orbit angle appears quite level to our horizon this time of year thus not providing sufficient height above nor below the position of the Sun to allow for favorable observations. Mars rises in the east around midnight and night by night slowly drifts to the lower left of it's contemporary rival, the orangy star, Aldebaran. Mars and Aldebaran are both below the misty patch of the Pleiades star cluster. By December we will have caught up to Mars sufficiently so that Mars will appear to rise earlier and show much more detail in telescopes (can you model this racetrack effect kinesthetically?) Don't confuse Mars with brilliant orangy Betelgeuse, the famous red supergiant star of Orion, to the lower right of Mars.
Enjoy this trio of colorful objects: Aldebaran, Betelgeuse, and Mars as the winter progresses. Compare them to the bright and much yellower star, Capella, to the left of Mars at the other end of the large constellation, Auriga.
Brilliant Venus leads the pre-dawn eastern sky parade by the second week of September, followed by Saturn, a bright golden dot, both rising in the east just before Sunrise, but earlier each morning. These two planets continue to appear to travel in concert for several months. Brilliant Sirius (closest large star to us in Northern Hemisphere, hence brightest) will contend for brightest dot with Venus in that region of the sky but Venus comes out the winner all the time.
Try to locate Uranus and Neptune, they'll hang in the southern evening sky for several more months but you'll need a sky chart to find them by starhopping (Uranus is sometimes naked eye visible, and you should be able to detect the bluish dot of Neptune with binoculars.)
Many students realize that our Sun, our home star, is much larger than Earth and even much larger than Jupiter (If earth is modeled as a mini basketball, 8 inches in diameter, the Sun would be modeled by a superball about 100 times bigger, about 70 feet across (Jupiter would be about 10 times larger than Earth but still falls 10 times smaller than the Sun!). (How do we know this? We can make several varieties of measurements to yield our distance from the Sun, then if we measure the angular diameter of the Sun's disk (never look directly at the Sun!), we can calculate the distance spanned by the angle knowing the ratio of rise/run of any triangle of that angle...it's about half of a degree, and we're almost 100 million miles from the Sun, try a calculation.)
But, we've found some stars, red supergiants, that far exceed the size of the Sun. The biggest one known used to be the Garnet Star, in the constellation, Cepheus. In 2005 discoveries were made of three other stars whose diameters measure about 1500 times the width of our Sun, or roughly 7 times the size of Earth's ORBIT around the Sun! (How do we know? Basically we translate brightness into the factors that account for brightness: distance, temperature, diameter, intervening materials...how certain are we? Fairly for these objects as they're relatively close.)
Quoting from the release at the AAS meeting in 2004 and 2005, "These are not abnormal stars. Rather, they're bloated senior citizens suffering a fate similar to that forecast for our Sun. However, the Sun, now middle-aged, has never been and never will be as massive as the supergiants, and so it will only achieve red giant status at about 100 times the diameter it is today. Even that will be bad news for Earth in a few billion years.The newly crowned largest stars, already known to astronomers as KW Sagitarri, V354 Cephei and KY Cygni, are all in our Milky Way galaxy and within 10,000 light-years of the Sun. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers)...
...Despite their tremendous diameters, the stars are not the most massive in the universe, said MIT undergraduate student Emily Levesque, who presented the findings. At just 25 solar masses, these red supergiants would look like wimps in a weigh-in against stars that can be up to150 times the mass of the Sun.
The most well-known red supergiant is Betelgeuse, which is about 650 times the diameter of the Sun and, owing in part to its proximity, is the 10th brightest star in our night sky."
Using a detailed sky chart, you should be able to locate and see these three new champions plus Herschel's Garnet Star with binoculars or a small telescope (Betelgeuse is easy with unaided eye, marking the upper left corner of Orion).
Speaking of high MASS stars, further findings were released:
"A team of researchers has found what appears to be the most luminous known star around, one so massive that it shouldn't have formed in the first place.
The star, known as LBV 1806-20, tips the scales of stellar masses at about 150 times the heft of the Sun. It shines up to 40 million times brighter than the Sun. The previous title-holder called the Pistol Star, is a mere six million times brighter than the Sun and weighs about 100 solar masses.
LBV 1806-20 was known before, but just as a bright blue object in high-powered telescopes. Now it has been examined more closely. Even if it proves to be a binary or triple-star system, and therefore all the mass is not its own, it would still be behemoth, astronomers said here yesterday at a meeting of the American Astronomical Society.
"It's definitely not a cluster of stars, we can rule that out completely," explained Stephen Eikenberry, who led a team of researchers that studied the star. "It could be part of a binary or triple system, though it seems unlikely."
Light from LBV 1806-20 undergoes periodic variations that seem specific to a one-body object, Eikenberry said. If it is eventually found to be a binary or triple-star system, it would be even more confusing, since astronomers would have to explain how these massive stars manage to exist so close together, he said.
Doesn't make sense
Current theories of star formation fail to explain the existence of big, bright LBV 1806-20, since it should have destroyed itself before it ever ignited. Astronomers long believed that as young stars grew to 120 solar masses, their energy output would burn off any excess. That is, the heat and pressure within the still-forming star would be so great, it would shear off any additional material from the star's surface.
Eikenberry is a professor of astronomy at the University of Florida.
One possible answer to the mystery of LBV 1806-20's continued existence could be the neighborhood beyond the star's immediate surroundings. The star resides in a cluster populated by extremely rare star or unusual stars, including a intensely powerful magnetic neutron star and a massive protostar, one yet to be born.
"So it's part of a giant cluster of freakishly massive stars," Eikenberry said.
LBV-1806-20 may have formed in what Eikenberry called "violent, triggered star formation." In the process, a huge, massive star reaches the end of its lifespan and explodes in an intense supernova. The shockwave from that supernova then hits a young star just as its forming, compressing gas around it quickly -- over a period of 100,000 years or so -- at forces greater than the star is able to blow off on its own.
Twinkle, twinkle massive star
Despite LBV 1806-20's luminosity, it is all but hidden to researchers on the ground. From Earth, it has a magnitude of 8.4, beyond the limit of about 6.5 on an astronomer's scale in which larger numbers denote dimmer objects. It's relatively dim terrestrial eyes because it sits about 45,000 light-years away, on the other side of the Milky Way, and is almost completely obstructed by interstellar gas and dust. One light year is the distance light travels in one year, or about six trillion miles (9.7 trillion kilometers).
"Almost 90 percent of its light, visible and infrared, is absorbed by the interstellar medium," Eikenberry said.
But that doesn't mean the star is invisible.
Eikenberry and his team were able to sharpen infrared images of LBV 1806-20 taken by the eight-foot (2.5 meter) telescope at the Palomar Observatory in California using a camera equipped with "speckle imaging," technology designed to mitigate the interfering effect of the Earth's atmosphere on star observations. The team also used data collected with the four-meter Blanco telescope at the National Optical Astronomy Observatory's Cerro Tololo Inter-American Observatory in Chile.
At its dimmest, LBV 1806-20 would be just as bright as its closest competitor, Pistol Star, with a temperature range of between 18,000 to 36,000 degrees Kelvin. Because it burns so bright, the star should have only a limited lifespan. Bright, massive stars tend to burn themselves out rather fast.
"These types of stars only run a short, violent, time, about two million years," Eikenberry said, noting that Earth's Sun is about five billion years old. "They tend to erupt and do really bad things to themselves before they blow themselves to bits."
Stars like LBV 1806-20, which Eikenberry estimates is only middle-aged at about one million years old, can shed huge amounts of material in a wind similar to solar wind of the Sun. He said the huge star could end in a hypernova explosion with a powerful burst of gamma rays."
This question is frequently asked by students and by teachers. Astrophysics educator Andrew Fraknoi, one of the "deans" of the astro education community, an officer of Astronomical Society of the Pacific, and teacher at Foothill College in California, constructed a very complete explanation that he posted to the Astronomy Education Journal, which he co-edits and is online for your reading pleasure.
Andy starts with our Rotation and Revolution and goes from there:
Need an image of a Planet, Nebula, or Galaxy, either a current one or perhaps one of historical venue? Need to know about current spacecraft?
JPL (Jet Propulsion Laboratory in Pasadena, Cal.) runs the actual probes that go to Mars, Saturn, etc., so go to http://www.jpl.nasa.gov/.
NASA oversees most of the Space Based Telescopes that orbit Earth, see http://www.nasa.gov/ where you'll also find all the Shuttle info and other info about the Manned Space Program , and the Project Starchild website for youger students: http://starchild.gsfc.nasa.gov/docs/StarChild/StarChild.html
(and don't forget, Tony Leavitt is our Oregon AESP NASA traveling rep, you can arrange for him to visit your classroom, contact Tony via "Tony Leavitt" firstname.lastname@example.org particularly for programs about the NASA exploration missions including Earth Science/Weather/Geology/Biology topics.
Tony's Cell # is (360) 624-2649, his visits are free but typically need booking a year in advance.
Space Telescope Science Institute runs the Hubble Space Telescope, see
http://hubblesite.org/ where there are links to Amazing
Space and other youth oriented sites/activities.
Chandra X-Ray Telescope is run by Harvard
Spitzer Infra-Red Telescope is run by CalTech
Don't forget about Astronomy Picture of the Day (APOD)
has extensive search index, you should be able to find any image you want.
European Space Agency is becoming more and more involved in a
variety of their own and collaborative missions:
The Japanese Space Agency, JAXA, is also very active:
Want to know when the ISS or the Shuttle will be visible (as a bright dot rapidly moving
across the darkened sky), or when an Iridium flare will be seen?
Is tonight's weather going to be good for sky viewing? Canadian Meteorologist Attila
Danko's Clear Sky Clock site offers very accurate short term predictions:
Need free monthly sky maps?
How about knowing when the various Moon phases will occur?
Please let me know what other resources you'd like, I'll try to find them and post their URLs, we will have a new compendium of URLs posted to the FOPMO website shortly, the original ASTRONOMY on the INTERNET INDEX is still available from http://pmo-sun.uoregon.edu/~pmo/astrosites.html in a link from the right hand column on our homepage.
Ever wonder if NASA ever offers opportunities for students and teachers to work on actual practical projects? The answer is a resounding YES, but locating these notices can be tricky. Fortunately, Laura Peckyno of our own Oregon Space Grant Consortium, has offered the URLs:
The most comprehensive NASA hosted URL is the "Act Now" page found at:
Laura says, "NASA does not update as frequently as I would like. Also, many
opportunities never end up on the site. You might have better luck with our local Resources
Blog found at:
I update the blog daily and you can search it for specific topics. It's also organized by category (see the key words on the left side of the page), allowing educators and students to find information relevant to their needs."
from Laura Peckyno, OSG Public Information Specialist
Oregon Space Grant, OSU, Corvallis August, 2007
Friday, October 12th (in service day) at Milwaukie, Oregon!
Great opportunity to share teaching ideas, pick up many gadgets and new ideas, meet colleagues, learn what's new from the ODE, and have a great time!
I'm presenting two sessions: one on how to make a simple Planetarium for your classroom, the other, how to access digital databases to allow you to locate particular stars and other desired targets in crowded fields of the sky and how to determine if that moving object you've found is a truly new asteroid.
Pre-registration highly recommended.
All the details and registration forms are at http://www.oregonscience.org/
See you there!