Sunday, August 30, 2009

Let the Exploring Begin!!!

Almost all children have an unquenchable thirst for information. Kids have a natural curiosity about the world we live in. See picture!!! When they get a chance to look into the eyepiece of a telescope or put a set of binoculars up to their eyes and behold the beauty of the night sky, that’s when the questions really start to fly. It is a real joy to be able to share what I know about those splendors set in the rich tapestries that is our night sky. 2009 is the International Year of Astronomy. This presents a perfect opportunity to let your children experience what Galileo saw 400 years ago. For most of you out there, this quite possibly will be a moment for you to be amazed as well. I have been doing this Astronomy thing for 42 years now and I still get blown away every time I take a look. But Steve Ole buddy, I have no idea where to start. To that I say right here my friend. Let’s start out by getting ready for the event because that is what it is when you and your kids or Cub Scout den or group start to really look at the night sky.

There are several avenues to take here and we shall touch on them all. The first solution is to go to your local planetarium. This will prepare you and your children for the wonders ahead. The presenter will talk about constellations and all manner of things to look for in the night sky. This is a great base from which to start. Now if you do not happen to have a planetarium in your area then no worries. You can do the same thing under dark skies. Preparing for this night is not a huge deal. You need an atlas of the night sky (Library) and some gems of information to peak your audience. Some gems can be as simple as how big the moon is or how far away it is Those dark spots on the moon were thought to be seas or oceans but we now know it is where the moon was struck by a huge asteroid and cracked the crust of the moon sending magma from the Moon’s inside to the surface to fill in the cracks and crater. Compare it to a volcano here. Simple stuff like that… When you have stuff crashing into one another then you have their attention. Now I realize that you may not be able to get all the “stuff” you want to share with the kids into that noggin of yours. That’s what delegation is all about. In scouts, or most every group you will have another leader or parent there to ride herd on the group. Perfect time here to let that person relay a few bits to the group. What does this do? Number one, everyone is engaged in the process. Number two; you split up the teaching or presenting to make it less boring. This is always a win–win situation.

Your local Astronomical club will have a program for groups. It can be done at the headquarters of the club or taken to your site. Just have a chat with the outreach director there he will be able (in most cases) to fill your needs. Some clubs charge a fee for this while some do not. The program can be as simple as drawing the constellations and then go out to look at them and locate them to discussions of the planet Jupiter then go out and see it through the telescope. If the site is dark enough, the club representative can show your group planetary nebulas and Globular clusters through his scope or scopes. These are sure to grab the kid’s attention and then of course there is the moon. This is a whole presentation in its self. The really great thing about using the club’s resources is they have access to many thousands of dollars worth of equipment and a slew of knowledge. The other thing is they have done it many times before and are used to speaking to the public. I know this can be a problem for some people. I highly recommend this solution.

Lastly there is one solution open to you and that is public events put on by the local clubs or the local observatory. These can be public star gazes or even a meteor shower party. They will not be as focused on your group but will provide a very good time to all. To find a public event near you all you have to do is call the local club or look on their website. If you have an observatory close by this will be a grand opportunity for the kids to look through a really big telescope. Observatories like Astronomy clubs have their own programs. Their outreach programs are first rate and can be brought to the school if needed. One last thing, it does not have to be at night. There are solar programs for your group to enjoy. Clubs as well as the observatories have special scopes that have filters that let you see the sun and it’s spots and prominences (big loops of gas and plasma) safely. So take a moment and think about getting your child, children, group or even hoard of kids to the nearest event. Be it at the local astronomy club, observatory or even one you direct. It will be a time of wonder under the stars for them and you as well!

Clear skies and great seeing too!

Steve T

Sunday, August 23, 2009

How Far We Have Come

The last couple of days I have been doing updates on some presentations I give to keep them current. When I give a presentation I like to have it an up to date affair instead of an ancient history lesson. I had to make at least seven major reworks of information within this one presentation on Exoplanets. Wow Seven new and exciting discoveries since I wrote the piece less than six months ago. I woke up this morning and just could not shake that awe struck feeling that we are living in some very exciting times, crappy economy aside. This is an age of discovery that rivals the renaissance period of history. It is arguable that today surpasses the discoveries of Copernicus, Galileo, Kepler and beyond. One thing is certain. We scientists of today stand squarely on the shoulders of those giants just mentioned. Just 400 years ago man invents the telescope and now some 10 generations later I am seeing data from the Kepler space telescope as it searches for new planets not here within our solar system, but in star systems some 400 light years away or farther. Now get this... Kepler is looking at not one star at a time oh no... try 100,000 at a time! It will stare at this area for 3 1/2 years measuring drops in brightness from each of those stars and determine the mass and orbit of earth sized planets as they transit their star from the telescope's viewpoint. Are you kidding me? 400 years ago we had a heck of a time getting bubbles out of the glass well enough to make a lens for a telescope. I had a chance to put together a 15 dollar Galileo scope These were put out by the International year of Astronomy For 15 dollars you get a pretty cool scope and you can also see what Galileo saw when he turned his scope on the moon or Jupiter. What would he say now about the Hubble telescope? This last 400 years has been a total blur when it comes to science. 400 years a go we were blood letting as a cure. Today we have mapped out the human genome.With as much as we now know about the world and universe we live in, there is a lot more we do not know. Like why is there an acceleration in the expansion of the universe? What made it speed up? Dark energy? What the heck is Dark energy? I could go on... There is one area of Astronomy that needed to catch up to the rest of the pack. Astrometry was like the little guy on the playground. Try as he would he could never get the touchdown. Undeterred, out he came every day to try. Well boys and girls the Touchdown has come for that little man!

Astrometry is the science of measuring stars and their exact positions in the sky. I know that sounds kind of easy to do. right? Hardly! Astrometry goes back way before Galileo. Way back to the astrologers of ancient times They would use a simple instruments to measure angle and distance between stars. This has been going on for some time and as time moved on the instruments got better and better. They got to a point in the early 40's that Astronomers were usin
g astrometry to look for planets circling a distant star. Yes, the first exoplanet search was on! Alas it was not to be... Oh there were the announcements in 1943 of astronomer Kaj Strand. He was working at the Sproul Observatory at Swarthmore College and announced that his astrometric measurements revealed the presence of a planet orbiting the star 61 Cygni. This claim remains unproven... Sproul was at it again in 1960 as Sarah Lippincott announced that she had located a planet circling around Lalande 21185 again the scientific community was sceptical of the find. Oh and how about Bernard's star? the director of Sproul, Peter Van De Camp detected a planet orbiting this red wonder of a star. The lack of proving it was the problem because there is a huge amount of difficulties with measurements this precise here on Earth Proper motion orbital mechanics, atmospherics the precision of the instruments being used as well as the calibration of those instruments. You need a calculator to keep up with the amount of variables involved.

Things quieted
down for astrometry for awhile with no wild claims being bandied about. You can only get so many black eyes. But just because no one was making claims did not mean that work was progressing on this very old branch of astronomy. Move forward they did, perfecting instrumentation, eliminating variables trying to bring astrometry back into the mainstream of exoplanet searching. In 1995 astrometry's hopes were dashed to bits as Radial velocity or Doppler spectroscopy bagged that first exoplanet so Now we stand at about 356 planets found so far using every way except Astrometry,that is up until May of 2009. The team at Mount Palomar, using the (ground based!) 200 inch Hale Telescope, delivered. Steven Pravdo and Stuart Shaklan of JPL announce the detection of VB 10b -- the first planet discovered through astrometry. The crowd goes Wild!!! Finally Astrometry has put the big boy pants on and moved up to the big show.

So what is next on the continuing parade of firsts? Your guess is as good as mine but it is so refreshing to me to see the little guy make it finally.The theory was genius. It just took a little time for the tools of the trade to catch up. We now have the twin Keck scopes out in Hawaii doing astrometry as well as others in Chile and around the world. It will not be long and we will start seeing exoplanets discovered by astrometry more and more. When Gaia is launched by the ESA, the numbers should really start to fall for astrometry. We have come a long way indeed!!!

Clear skies and great seeing too,

Steve T

Saturday, August 15, 2009

OK What Gives? Is It Meteoroids , Meteors or Meteorites?

Hello from Columbus Ohio I am escorting my precious daughter Meghan in a pageant here but I will always have the time to upload my blog . Just wanted you to know I did Dad stuff too!
Now for most everybody out there this is a great question. Here is the odd part Those three words refer to the same exact object. Hey, as you are finding out science makes things a bit more complicated at times than absolutely necessary. For the next few minutes we are going to talk about what makes Meteors tick but first lets get rid of the three word thingy.

Meteoroids are the object. Be it from Mars, the Moon, asteroid or comet that is still outside of Earth's atmosphere. Sort of picture the "Before" shot. Now how big can they be?Well... pretty big all the way up to (what happened to the dinosaurs?) big. That was a very big rock (about 10km wide) that crashed into the Yucatan peninsula 65 million years ago. They can be as small as Dust or crumbs coming from a comet. On to Meteors. When a Meteoroid penetrates our atmosphere, heat builds up because of friction Etc.. The heat builds and the meteor( as it is called now) starts to vaporize. That's when you can see it as a streak of light against the night sky. There have been Meteors seen in broad daylight. That is one bright meteor. In the game, that is called a fireball. Picture a rock that has traveled through space, (meteoroid) has entered Earth's atmosphere then set ablaze (meteor) but it is still coming and wham it hits the ground or in this case here a car... The second it hits the earth it becomes (as if by magic) a meteorite! This car pictured has traveled the world on exhibit. Fatalities from Meteorites? Well.... in 1930 a Cow was struck and killed by a meteorite. How about this one. In 1954, a woman living in Alabama was struck and injured while taking it easy in her easy chair. I would say she had a great story to tell!

Now Let us classify Meteorites into three categories for simplicity's sake. They are Stony Meteorites, Iron Meteorites and Stony-iron Meteorites. Stony Meteorites are made out of well... stone. I know you were probably ahead of me on that one but there are little jewels inside these meteorites that tell a tale of how our solar system was formed. These little round beauties are called Chondrules. They were formed when the Solar system was cooling off. They solidified into spheres and then were accreted into larger objects. Eventually these objects were to become the asteroids we know today. Some stony meteorites have a slew of chondrules while others not so much and this is due to the way Asteroids form. If they had high heat applied while forming then chondrule will be found less often. Cooling fast resulted in many chondrules. That's one of the reasons why stony meteorites are so varied.

Iron meteorites are just that and more. They include combinations of iron, nickle and cobalt with iron being the lions share of the mixture. They have some mass to them let me tell you. An iron meteorite hit Winslow Arizona some 25-50,000 years ago. That left a big impression on the area! A huge crater resulted 750 feet deep with a circumference of 2.4 miles. It is about 550 feet deep now. This particular Meteorite vaporized almost completely when it hit the ground. There were remnants of the event scattered for miles with this fine iron spherical dust everywhere (Vaporized). So we got a huge crater and no meteorite. Well try this one on if you go to Africa you will get to see the worlds biggest iron meteorite. It sets in a field with no Crater to be found. Now Steve ole buddy How can that be? I'm pretty sure no one moved it as it goes about 60 to 70 tons. Have you ever skipped a stone across the creek? Scientists now believe that's what happened. The meteor came in at a low angle and skipped along until it came to rest in a farmers field in Hoba.You just never know what you are going to run into when it comes to meteorites. That kind of sends us into the next class of meteorites. Stony iron meteorites are some of the prettiest objects you will ever see. Iron with crystals buried in it. Does it get any better than that? They are so beautiful to look at. These are pallasites and they are stunners.

Alright Steve I am sold! Point me toward the meteorite field. To be honest meteors fall everywhere and pretty evenly but If you want to find them, go where the terrain looks least like Meteorites. Can you guess a really COOL place? Antarctica is a great place to look as the Meteors sit on top of the ice. Wind erodes the snow and leave the stones for the harvesting. OK maybe you don't have a hankering to freeze your tukus off looking for off world gravel. in that case try the Sahara desert white to light brown sand. When a blackened meteorite hits the that sandy floor it kind of sticks out like a sore thumb.But again you might not have the cash to go to Africa. Have you tried Kansas? yep that could be a little better. Just look in the freshly turned over fields and hey you just might find a meteorite to hand down to your kids.

Clear skies and great seeing too,

Steve T.

Sunday, August 9, 2009

Put Up The Umbrella Stella There's Going To Be A Shower

The Annual Perseid meteor showers are upon us. There is nothing better in this world than to lay on a blanket with the love of your life staring at the sky in hopes of catching a glimpse of a meteor streak across the sky. When they turn to you and ask," Hey Honey. Just what is a meteor?" The last thing they want to hear is Uh... I dunno. It kind of ruins the moment if you know what I mean. Fear not for I am here to give you a crash course on meteors because "uh... I dunno" is a real mood killer. I just love doing public service work!!! To begin with, I am going to break down where meteors come from and then how we classify them. The one thing I am not going to do is list the 2000 different classifications of meteors and how they are broke down into chemical features. The reason is because the common Joe,will be put to sleep by all those numbers and symbols. Remember why I am telling this to you. The last thing your love wants to hear when they are cuddled up next to you is "An Octahedrite is a broad class of iron meteorites which is characterized by the presence of both Taenite and Kamacite nickle iron minerals in the crystal structure of the meteorite" Do you see what I mean?

Meteors come from three main sources, The first source to touch on are asteroids. Our Asteroid field located between Mars and Jupiter can be a violent place at times. Impacts on asteroids can and do cause chunks of debris from the asteroid to fly off and head elsewhere and sometimes that elsewhere is Earth. Asteroids are just like people in that they are all different. They can be Iron nickle rich or just a big stony rock or any mixture in between. When an iron asteroid impacts a stony one things get kind of mixed up stuff fuses together so there might be areas of a big asteroid that might exhibit all three forms because of impacts. When things were not quite cooled off during the start of our Solar system, There was a lot of bumping into one another going on quite regularly.Add to how hot the mixture got how fast it cooled and you have a real hodge-podge of stuff floating about out there. To quasi-quote an Esteemed twentieth century philosopher Forest Gump, "Asteroids are like a box of chocolates, You never know what you gonna get"

Meteors come from places you might not think of like the Moon or even Mars! Picture in your mind a pretty good sized chunk of rock headed towards the Moon. There is no atmosphere to slow it down. Additionally there is little gravity. When the moon gets thumped pretty good by an asteroid or big meteor, the ejecta (the cloud of debris) gets launched out into space. This pile of rock travels willy-nilly spreading out. As it passes by another planet (earth), the gravitational force sometimes grabs that rock and sends it plummeting to the surface of that planet. The moon is easy to get your head around sending rocks our way destined to become meteorites. Mars ? are you kidding me? Now Is a Martian meteorite a rare find? You bet it is. They are out there. Think how big of an impact you would need to shoot a rock from the surface of Mars to the surface of Earth. Now that's an impact!

Last but not least are Comets. They are the driving force behind Annual meteor showers. When a Comet has its frozen outer layers blown away as it passes our sun, the sand and rocks that were stuck in the ice are now free and travel the same path as the orbiting comet. If this comet's orbit happens to cross the orbital path of Earth, then this will lead to the debris hitting earth's atmosphere as Terra (Earth) moves on its merry way around the Sun. This diagram shows this process pretty well. That is why we have several annual meteor showers because we hit their orbit of left-overs The Comet responsible for the annual Perseid meteor shower is called Swift-Tuttle. It is named after the two people who discovered it. That will be enough to wow them for this Meteor shower. Peak is on the twelfth of August so look up and enjoy the show!!! Next week, Which is it Meteoroids, Meteors, or Meteorites? Until then,

Clear skies and great seeing too

Steve T

Sunday, August 2, 2009

Is There a Perfect Finder Scope???

(NOTE) This question is sort of like asking, "what is the best flavor of ice cream?". You will get many different answers. So to a beginner, this might lead to a confusing situation. Here is where I get a chance to straighten out the road a bit for you.

You have bought a nice scope and it came with this little teeny tiny telescope. What the heck is that for? That is the finder scope. It will assist you in getting your scope aligned with the night sky. Some folks use a finder all night long as they move there scope manually across the sky, star hopping to their next target. Some folks use it to setup their electronic motorized goto scope and never look through it for the rest of the night.There are those of us that have put our finder scope in the box and never get them out because we have other means of getting the scope aligned. This can be in the form of a red dot finder or even a Telrad finder that uses a recticle with a bull's eye pattern to get you aligned or star hopping. To get this thing straightened out we will look at the different finders and their application to each scope type.

This is your typical finder scope found on most telescopes it is a straight through design The image will be inverted upside down. It will take a little time to get comfortable using an inverted image finder when you are looking in the finder and every fiber of your being is telling you to move the scope right to center the object. You must go left. This can be mind bending when star hopping but you will get used to it. Probably... I have seen straight through finders on every scope practically made. As with all finders the bigger, the better the light gathering. Keep this in mind if you are getting another finder for your scope. Finders are wide angled so they see a bigger chunk of the sky than the main scope. That is why we use them to kind of whittle the sky down to where your target lies.What Telescope(s) would be best for this venerable design? Catadioptric ( SCT, Maksutov etc.) and refractors are best suited for the simple reason the eyepiece is in the same direction as the main scopes eyepiece no jumping around the scope to align it. There is a little twist to this finder scope. It can come with a illuminated recticle (Cross hair) which is a huge plus in the deep dark of night.

The right angled finder is a wonderful design if you are more worried about a stiff neck. When you are trying to find something high in the sky you will notice your straight through finder has become very difficult to use. You must get down on the ground and look up through the eyepiece. The older I get the more this rings true. The right angled finder has been the savior for many a neck and knee low these many years. There are two schools of thought on right angled design One is the corrected image camp. This system makes aiming your telescope easy by showing an upright, non-reversed image. This is pretty easy for the brain to digest. Right means right. right? So if confusion is the issue when aligning your scope then this is the one to get plus your neck will be happy.The other camp will tell you while the simplicity of moving the scope has been improved with the correct image it is not showing the same image as what is in the Catadioptric scope. The solution is the right-angle first-surface mirror diagonal. It gives images that are upright, but mirror-image reversed, just as they are in the eyepiece of a catadioptric telescope. This makes the finder very useful with Schmidt-Cassegrain scopes, as the image orientation of the finder matches the upright mirror-image orientation you see in the main scope’s eyepiece. This is just something you as Joe/Josephine Consumer will have to figure out which one is best for you. If you use your scope for birding etc get the correct image right angled finder. You will find Right angled finder scopes on all scope but I highly recommend them for Newtonians

Red dot finders do not magnify. For anything that you can see at night they rock. when aligned with the scope it is a simple thing to align the scope especially with goto scopes center the dot on what ever star and go to the next one very quick no out thinking your brain when it comes to moving the scope right is right up is up. they are usually in line with the direction of the scope. Objects high in the sky can be a pain to align with.There are some red dot finders designed with a mirror so they can be used as a right angled unit that's a nice feature Some red dot finders have circle recticles for star hopping these do very well. One draw back is they take batteries. They almost always use the disk type. Running over to the handymart to get a battery might be a problem. You will find these very handy for any scope out there. I also see them sitting right beside their magnified finder scope cousin right on the same scope. They will be a great addition to your scope stuff.

Last and far far from least is the reflex site. A Telrad ( the brand name) for many many astronomers was and is the answer to many a prayer. It is a simple yet very effective siting mechanism for aligning your scope. Like the red dot finder, they employ a red led. I use a Telrad and only a Telrad on my Celestron CPC scope. The mounting mechanism is so that you unscrew the keepers and the Telrad comes right off the base. You may put it right back on the base and not have to align it with the main scope again.It will be very close to right on. It takes more time to put my finder scope on and get it aligned to the main scope than to just throw the Telrad on and align the main scope period. Using the Telrad, I can have my scope very accurately aligned using three star alignment in under 5 minutes with usually 3 minutes being the average. Now when it comes to star hopping with a Dobsonian mounted Newtonian telescope you can not beat the Telrad. The Telrad projects a series of concentric red rings (4 degrees, 2 degrees, and one-half degree in diameter) on a tilted clear viewing plate at the top of the finder. These circles make it easy to starhop from object to object. If a galaxy is 10 degrees north of a known star, for example, two 4 degree Telrad jumps and one 2 degree jump from the known star will take you to that galaxy in seconds. The red circles can be seen from almost any distance behind the Telrad, 2"" to about 2 feet so eyeglass-wearers can use the finder. Rigel also makes a reflex site also but for almost everyone the Telrad is the one. You can find this jewel on the scope of most seasoned telescope owners. Draw backs are some people can not seem to get lined up with the image and keep losing it I have not ever had that problem it is just a matter or moving your head slightly till you find it. they also make a right angle attachment for them to help on neck breakage. This puppy takes a 9Volt transistor battery The battery lasts forever it seems unless you forget to turn it off. Telrads will be found on all scopes but mostly on Newts and Cats. They are kind of big so they look a little odd setting on a small refractor.

So the choice is yours. There is no perfect finder out there but the Telrad come close in my book. Unless you are made out of money and just buy them all and decide ( Wife would not go for that idea) Do the research ask your fellow stargazers what works for them and why. Does that fit your needs. I am in love with my Telrad and always will be but I will never tell you that is what you need to get unless you look through one and say this is so cool!Then I might. You need to fit to the finder. Make a good decision and go have some fun . and if you are not happy with that finder scope send it back and get something else like say a ........ Telrad.

Clear skies and great seeing too,

Steve T