It’s a Big Galaxy Out There

Last month, I was trying to remember how far away an open star cluster was. I was showcasing NGC 457 at a state park star party. This cluster is a cute appearing cluster in Cassiopeia. It is called the ET cluster or the Owl cluster. For kids these days, I call it the WALL-E cluster.

Since I could not remember its distance, I came up with something that seemed like it might make sense. I said that it was probably a couple hundred light years away. Boy was I wrong. I should have just said that I could not remember. Now there are maybe a dozen kids and parents roaming the world thinking that ET is a lot closer to home than he really is…

Of course, hundreds of light years away is still a long, long way.

Here is one way of thinking of these distances. It is about 3000 miles from the east coast of the US to the west coast. The circumference of the earth is about 24000 miles. Light travels at about 186000 miles in one second.

That means it would take about 1/7 of a second for light to circle the earth. 1/50th of a second is all it would take for light to make it from the left coast to the right coast of the US.

The moon is about 240,000 miles from the earth on average. So it takes about 1-1/3 seconds for light to travel from the moon to the earth. The sun is about 93,000,000 miles from earth. So it takes about 500 seconds or 8-1/3 minutes for the light from the sun to reach the earth.

Jupiter is hanging high in the evening sky right now. It is about 484 million miles from the sun. That is five times as far as the earth is from the sun. One way to talk about distances in the solar system is to measure in Astronomical Units (AU). One AU is the average distance of the earth from the sun. Jupiter’s distance from earth ranges from 4 AU to 6AU. In light minutes, Jupiter’s distance from the sun is about 41 minutes. But when I look at Jupiter right now, the time it takes for light to leave the sun, travel to Jupiter, reflect off the clouds and come back to my eye is closer to 80 minutes – almost an hour and a half.

I was pointing out Neptune to one of our club members from the light polluted city streets of San Antonio last week. Neptune is 4.5 billion miles from the sun. That is about 6.7 light hours from the sun. When I was pointing out Neptune, its light had been traveling for more than 13 hours since it left the surface of the sun. Another way to think of Neptune’s distance is that it is about a million times as far away as the distance across our country.

But that’s just peanuts.

The second nearest star is about 3 light years away. That’s 2000 times as far away as Neptune. Sirius, the brightest star in our sky is about 8-1/2 light years away. Star clusters are much further away. The Pleiades are a close cluster and are about 440 light years away. Maybe that is what I was thinking when I told my listeners that the ET cluster was several hundred light years away. As it is, the light from the Pleiades left those young suns about the time that Galileo was born.

But the ET cluster is a lot further away. When I finally looked it up while hiking yesterday, I was taken back when I read that this cute little open cluster is about 9000 light years away. The light I looked at the other night started heading this way about the time that people first began writing in Mesopotamia and the Chinese began making wine.

That’s a long time ago, and the galaxy we live in is a big place.

Astronomers look out for themselves

I've been at the Eldorado Star Party for the last couple days. The weather has been nice, with clear skies and pleasant temperatures. There was some rain in the last week and that has made dew a bit of a problem, and hair driers are frequently heard on the starfield at night.



Last night, Matt R. And I began the Texas Hash list. It is a lot harder than most of the TSP lists I ran last spring. We got through 15 objects we attempted last night, with only one object we could not find. We have another 10 to go tonight if we decide to proceed with the list.

It was sometime yesterday, while cleaning up camp to leave for lunch, that the title of this post occurred to me. We were talking about the fact that astronomers were a pretty honest crew. Nevertheless, it is never a good idea to leave expensive items lying around. We were cleaning up, "Because astronomers look out for themselves."

I laughed at the appropriateness of the words, because that is exactly what we do. Instead of looking at pictures of stars in books or the Internet, we stay up late at night to find and admire those objects ourselves. That is why it is about.

National Night Out

Last evening, I remembered that it was our Texas version of National Night Out (NNO) when I saw the 6PM news coverage of some events near San Antonio. Some months ago I had decided that the NNO might make a great time to have a neighborhood star party.

I walked to the front of the house and saw that the sky was relatively clear. We have recently had a lot of clouds, and I was a little surprised that there were few clouds in the sky.

It took almost 5 minutes to set up my Orion XT10 in the driveway and focus it on Jupiter. With a 10 mm eyepiece, the magnification was 120 times and the brightness was such that the bands of Jupiter were clearly visible.

Three star-like moons were arrayed to the right of Jupiter, toward the East it turns out. Jupiter would slip off the left side of the field of view every couple minutes. The fourth major moon of Jupiter was not visible behind its disc.

The top equitorial band (the southern one) had a great lump in its top edge. There was a small dark spot just to the right side of the lump within the band. In moments of clarity and improved seeing, I could make out the internal border of the Great Red Spot. Over the course of the evening, that Red Spot moved leftward (westward) until it seemed to be falling off the left side of the Jupiter "marble".

During the two hours I had my scope up, different groups of my neighbors that had been at the formal celebration of NNO at our pool walked past the house. I genially called them over to take a look at Jupiter. One group of kids, with their mom, spent quite a bit of time learning how to readjust the scope to put Jupiter back in the center of the field of view.

They had lots of good questions. How big is Jupiter compared with Mars and with Earth? How far away is it? Why are the moons in a line? What causes the bands on Jupiter and the Great Red Spot?

I had done some thinking since a couple recent star parties, and decided to try to answer the questions with the purpose of helping them to think about the process of science instead of a science text book. The same way that I had helped them learn to find Jupiter when it slid out of the field of view, instead of doing that myself, I wanted them to think about the answers to their questions.

So I helped them think through their questions instead of giving them textbook answers. How could one find out how big Jupiter is? How would it be possible to find out how far away Jupiter is? How long does it take for light from Jupiter to get to the earth? Why would you believe my answers when there are good ways of finding out answers?

It was interesting to see their reaction. They clearly expected to be told the answers to their questions - just like I was some kind of encyclopedia or Google search engine. But when I started asking questions in return, they either took it well or did not. Some were interested in the guy with the telescope that asked questions and some were bored.

I hope the effort will encourage some kid to get a little more interested in science questions. Maybe they will become interested enough to take a little more science than they were expecting to take in school. Maybe they will make a little better citizen or jurror in a case that involves scientific testimony. Maybe one of them will invent the cure for whatever disease or injury is going to try to do me in 20 years from now - or one of my children or grandchildren.

It felt good to challenge my charges a little.

Dark Skies!
Risk

Astronomy and Fitness

Over the last eight or nine months, as I have become more and more interested in astronomy, I have taken less time to hike and walk and ride my mountain bike. Unfortunately, I found that this had an effect on my weight and my waistline. My weight rose from about 185 to 215 pounds. At first, my 36 inch waist pants got tight and then intolerable. I moved to 38 inch waist pants and then they got tight too!

It is time for me to become a shadow of my present self. I need to weigh less. I need to be in better shape.

This week, my wife persuaded me to start joining her in regularly attending a health club. She has been very good at getting exercise for most of a year now, and finally I am on the way back to health too. I thank her for the encouragement and inspiration.

We decided to plunk down the money to join the local Spectrum health club after visiting the local clubs. Spectrum was lighter, a little less crowded, and smelled better than the other club we visited. It is close enough that I can get there after working my day job, instead of just wishing that I could drive to Lackland AFB to use their gym for free. Yeah, it was also a little more expensive.

So, here I am a few days later with some soreness of my muscles and I’m slowly starting my way down the weight loss path again. (I am reducing portion sizes and abandoning all snacks too.) I know it will take a number of months to get back down to fighting weight, but the journey has started.

Astronomy is a great activity, but the problem with it is that there is not much activity to it. If you are having as much fun under the dark sky as I am, maybe a review of your other activities is in order – like it was for me. We want to enjoy the sky for as many years as possible. Staying in shape and staying healthy is part of that equation.

Huff and puff,
Dark skies too,

Rick

Free Tools – Cartes Du Ciel and Virtual Moon Atlas

One of the premier tools available free to the amateur observer is the planetarium program that goes by the French name “Cartes Du Ciel.” True to its name, this program is a Sky Chart system that incorporates many of the features of full feature programs costing hundreds of dollars.

I have a number of sky charts that I find to be very useful in book form. When I am searching for a double star or a Messier Object, I really like these bound versions of sky charts. However, for some purposes, a software program is very handy. That is especially true when trying to track down comets, planets, and asteroids. The planetarium program can be set for today, or for next week when I will be out at a dark sky site. It can give different magnification levels, and I can create both right side up views for my finder scope as well as upside down and backwards views for my Dobsonian scope. Fact is, the program will also create right side up and reversed left right views for SCT scopes too!

For planning a Messier Marathon, the program is a great way to create a set of star hopping charts or to add to a published set, as I described in my Messier marathon piece last winter.

My preferred set up is to use a black on white format. It prints very well. With a red filter on a laptop computer it is also easy to read in the dark.

One of the ways I use the program is to print out a full sky chart to use instead of a planisphere for a certain time/place/and date. It is a little easier to show constellations to folks with this round version of the sky than a squished planisphere version – it also is more accurate than most planispheres for my south Texas observing location.

One of the things I like most about the Cartes du Ciel program is the ability to scale to any magnification and to add or subract star detail. This allows me to create simple charts and detailed charts on the fly. If I am interested in seeing very dim stars near where an asteroid is to be found in an eyepiece view, I can do that. If I am interested in seeing the overall picture of a full constellation, I can do that too.

Switching gears, I might as well mention the lunar equivalent of this planetarium program. The “Virtual Moon Atlas” is a great tool for locating almost all the small objects that one might be interested in on the lunar surface. It is a searchable atlas, and will identify any crater or feature that I click on the picture of the moon. There are several levels of complexity of the moon atlas. I have always used the biggest version. I really don’t know how limited the other versions might be.
Again the cool thing about this atlas is that it follows the libration of the moon, the phases of the moon, and the visible portion of the moon from any observing location. The view can also be adjusted up/down and left/right for any sort of scope.

Both programs can be downloaded from the Internet. Google search for them, download, install, and enjoy.

Astronomy Picture of the Day

While I am an incurable fan of looking at my own personal set of photons given off by deep sky objects, I can also be attracted to beautiful photographs of the same sky objects. I grew up with black and white versions of long photographic exposure time pictures that showed much more than I can see with my eye. These days, color photos and false color photos are all the rage. They are beautiful.

Sometime last fall, I decided to take an online course offered free by Robert Nemiroff (Michigan Technical University) from the upper peninsula of the state. It was an online collection of the lectures used for a college course. They were offered completely free as long as no college credit was needed. Dr Nemiroff is one of the editors of the Astronomy Picture of the Day (APOD). This is a NASA hosted site where one photograph or piece of art is featured each day. In the course, the students were responsible for knowing something about each one of the APODs for their testes.

I started taking a closer look at the descriptions under the pretty pictures. It turns out that the writing about the photographs is as well done as the photography. Here is a recent example:

“Why take a picture of just the Badlands when you can take one that also shows the spectacular sky above it? Just such a picture, actually a digital stitched panorama of four images, was taken in late June near midnight, looking southwest. In the foreground, the unusual buttes of the Badlands Wall, part of the Badlands National Park in South Dakota, USA, were momentarily illuminated by flashlight during a long duration exposure of the background night sky. The mountain-like buttes visible are composed of soft rock that show sharp erosion features from wind and water. The South Dakota Badlands also contain ancient beds rich with easy-to-find fossils. Some fossils are over 25 million years old and hold clues to the evolutionary origins of the horse and the saber-toothed tiger. Bright Jupiter dominates the sky on the left just above the buttes, while the spectacular Milky Way Galaxy runs down the image right.”

When I take a careful look at this prose, it is as illuminating as the photograph it described. Here is another recent description from the APOD site:

“Sprawling across hundreds of light-years, emission nebula IC 1396, visible on the upper right, mixes glowing cosmic gas and dark dust clouds. Stars are forming in this area, only about 3,000 light-years from Earth. This wide angle view also captures surrounding emission and absorption nebula. The red glow in IC 1396 and across the image is created by cosmic hydrogen gas recapturing electrons knocked away by energetic starlight. The dark dust clouds are dense groups of smoke-like particles common in the disks of spiral galaxies. Among the intriguing dark shapes within IC 1396, the winding Elephant's Trunk nebula lies just right of the nebula's center. IC 1396 lies in the high and far off constellation of Cepheus.”

I like the idea of the nebula sprawling across the heavens instead of many more prosaic ways of saying the same thing. I might have written something like “IC1396 I several hundred light years in diameter.”

I got into the habit of looking at the APOD each day while I was taking the course last fall. I keep a link to the APOD on my blog site. It is one of the great internet archives of both beautiful photographs and instructive descriptions of deep sky objects. There is a lot of cosmology to be learned just by reading the descriptions from a month’s worth of the APOD library. Enjoy them.

The daily APOD can be found at

http://apod.nasa.gov/apod/

Risk Management in Astronomy

One of my nicknames is Risk. Hence, “Risk’s Wildly Successful” series of helpful insights. The way I came across that nickname was my function in an Air Force laboratory as the champion for Risk Management.

Life would be pretty boring if risk was always eliminated or minimized. My goal has never been to eliminate risk, but to control it – and to never let risk control me. I enjoy the heart pounding experience of pushing my limits on a mountain bike, teeth chattering as I descend a rocky trail. I enjoy the experience of standing in front of 300 people with a brand new talk, knowing that a few of those people may know more about the subject than I do. I enjoy reading people’s faces and knowing whether I am talking over their heads, or whether I am being dreadfully boring. These sorts of things are the spice of life.

Something happened this weekend which brought back to my mind the necessity of practicing Risk Management in Astronomy. We were on the way back from Hill Country State Natural Area. My son was in the pick-up with me and his fiancée was in our Corolla with Diane. It was about midnight.

Somewhere on Bandera Highway, Diane fell asleep for a moment. She was driving the car and drifted left of the yellow line. Ashley was sleepy but awake enough to know that Diane was not playing a joke on her. She quickly woke Diane and both of them drove the rest of the way home with a fresh pile of adrenaline in their veins!

Its not that our family is unaware of the dangers of driving sleepy. I personally think it is now more of a problem than “driving drunk” for our society. Driving drunk may have been more of a problem in the past, but most people now know the severe penalties for driving drunk and avoid doing so.

That brought to mind the kinds of risks that we astronomers need to control in our sport. We all know the risk of looking at the sun with a telescope. It will instantly and permanently ruin eyesight to look at the sun with aided optics. But how many of us are very careful when moving a scope around during the daytime? I remember one time this summer when I happened to glance down the tube of a reflector to see how much dust was on the mirror. The sun’s reflection hit me hard in one eye! Stupid, stupid, stupid! It took 5 minutes before I was convinced that my eye was not damaged.

Driving around at night, we not only run the risk of falling asleep, but we have to stay on the alert for large animals in the roadway. Here in Texas, that means deer and pigs. Driving back from Hill Country, Diane and I have counted up to 17 deer next to the highway.

We have to be careful about heavy scopes hurting our backs, tripping over tent stakes, and letting large scopes crush fingers and hands. These are not idle threats. As I have written, the reason I got a nice camping spot at the Texas Star Party this year was that a fellow tripped over a tent stake going to a restroom and broke his leg.

We need to be careful about being alone in lonely places. The only people who have bothered me while observing at the side of the road have been policemen. But other observers have not been quite as lucky. We need to be ready to defend ourselves while in lonely places. We also need to make sure that we have permission to be observing. One significant form of my risk management is developing friendships of folks that are willing to allow me to observe from their property instead of stopping along lonely roads like I used to do.

But learning to only drive while awake remains the most important risk management technique. There are two means of controlling this problem. The first is to learn how to stay out all night. This takes some equipment and experience. The second control mechanism is to learn to stop driving whenever I get sleepy – before getting so sleepy that I nod off. It does not matter if I am 10 miles from home or 1 mile from home. There is ALWAYS someplace where I can pull off the road and take a short nap. Even a 10 minute nap will give me many more minutes of awake time. It is always OK to stop to sleep. Dad is not at home looking at his watch. Go to sleep after the wheels stop rolling. Really. Please.