Most people know that an eclipse is when one object passes in front of another object, thus “eclipsing” it and blocking it from a third object. When the eclipsing object is the Moon and the eclipsed object is the Sun, we see the Sun disappear and be replaced with a black circle. That’s because our Moon is almost the same angular size as our Sun, which means that they are about the same width as seen from the Earth. Even though the Sun is thousands of times bigger, its huge distance makes it look much smaller – about the same size as the moon.

Our Moon does not have a circular orbit, though. It’s more of an oval. And sometimes, when the eclipse occurs, the moon is closer to Earth and sometimes it is farther away. When it is farther away, it appears smaller. Even though the Moon appears smaller, the Sun does not, so the Moon covers less of the apparent surface of the Sun. This is called an annular eclipse, not to be confused with the word annual, and not to be confused with a partial eclipse.

In a partial eclipse, the Moon only partially covers the sun – the centers of their two discs never quite line up as seen from Earth. An annular eclipse is a true full solar eclipse where the centers of the Moon and Sun do line up, but the smaller apparent size of the Moon means the Sun will be seen as an annulus, or “ring of fire” around a dark circle in the middle.

If you live in the path of the event, you are in for a treat. Take proper precautions and be sure to look at the sun. If you do not live in the path of the event, try to find an online astronomy web site or group that will be broadcasting a live feed of the event. You will not want to miss it!

The camera was still on a basic photography tripod, and I was starting to get more familiar with the computer interface.  But I forgot to use the camera AC adapter, so the battery was dying on the camera.  I decided to change to the AC adapter.  But to change to the AC adapter, I had to take out the battery.  Which required taking the camera off the tripod, undoing the quick release catch, popping out the battery, and inserting the AC adapter into the battery compartment.  This meant I turned on a flashlight so I wouldn’t drop the new camera.

Lightning Strike

I put it all back together and went to go sit down in the chair with the laptop on it that was connected to the camera.  And promptly put my foot into thin air and just about killed myself falling off what passes as our back walkway.  Luckily the massive amount of wild mint that is growing there saved me from putting my face in the dirt.

And all I got was this lousy picture.  Well, maybe not so lousy.  In fact, this picture isn’t even from that night.  This is from a few nights ago when we had a major storm with more lightning than this Astropotamus can remember for quite a while.  Some handheld shots on bulb setting proved the easiest way to capture some of these strikes.

This one was one of my favorites.  Did you know that lightning is hotter than the surface of the sun?  More on that in a future post.

Winter skies are, perhaps ironically, easier to image than summer skies.  The heat differences between day and night are less, there are fewer mirage effects from heat coming off of the ground, and the atmosphere is generally less turbulent when it is cold.  The entire night sky is in a sort of slumber, with few things to make it move and shake and wiggle.

Orion, which sweeps through the early night sky and will be with us until almost summer, is a beautiful sight.  All of its primary stars are visible with the naked eye and it houses some of the most studied and photographed nebulae in the Milky Way.  This year, will be the year I image it.

Mrs. Astropotamus has changed. And she’s rearranging. Luckily, the change is a good one and the rearranging is for the best.

Mrs. Astropotamus works for a small company doing technical stuff and mundane stuff and all the stuff that makes an office work as well as all the customer support stuff. It’s been a great place for her to work. Now it’s time to change.

She is moving on and going to be doing things for herself. I joke that she has retired but i don’t think she really likes that joke. Regardless, she now has time on her hands that she didn’t have before, and one of the things she said to me was, “we can live anywhere now.”

True, that.

I’m not going to lobby for the clear skies of Antarctica just yet, but here are some places worth looking into:

• Tunisia. Home of some of the finest meteorites ever to survive entry into the Earth’s atmosphere.
• Australia. As if the Magellanic Clouds weren’t enough, there’s the Southern Cross, the entire set of southern constellations, and huge areas of dark, dark skies to set up Time Machines in.
• Costa Rica. While not yet known as a popular Astropotamus destination, I just like it there and would be willing to be the trailblazer that lures other Astropotamuses to this beautiful part of the world.
• Norway. Two words: aurora borealis.
• Patagonia. Two words: free wool. Which is good, because the Andes are cold and therre is some really good seeing up in those woods. So to speak.
• Hawaii. Keck. I say again: Keck. Oh, and everything else Hawaiian. Plus, let’s not forget Keck. Did I mention the Keck Observatory?
• Pasadena. Three words (or intials): JPL. What other place has such direct acces to so many wonders of the universe in beautiful, 75 degree weather all year long?
• Belize. Similar to Costa Rica but with more diving opportunities. Plus, Mrs. Astropotamus and I spent a great time there “back in the day.”

Ah, someday, we’ll have both money and time.

Noun: A very hard, granular, crystalline, intrusive igneous rock consisting mainly of quartz, mica, and feldspar and often used as a building stone.

gap/gap/

Noun: A break or hole in an object or between two objects: “he came through the gap in the hedge”

Granite Gap is a new community of Astropotamuses, astronomers, nature lovers, birders, educators, and all ’round nice people who want to be able to live at least part of the year in a dark place. Luckily, there’s a dark place in New Mexico and it comes with space for a private and permanent observatory, complete with power and high speed internet. That means that Astropotamuses like myself can set up their Time Machines, hook everything up to a computer, and then go somewhere else and still watch the skies, take pictures, and generally do cool astronomy stuff from anywhere on the planet. Well, anywhere with internet service.

Astropotamus is very lucky. In part because he already lives in a dark place and has no major source of light pollution within 20 miles. But there’s more to it than that. He’s lucky because he has Mrs. Astropotamus. Together, they decided to give each other the combined birthday and Christmas present of a 99-year lease on a plot of land at Granite Gap. This means that Astropotamus can go be like those other Astropotamuses and set up a remote-controlled observatory in New Mexico and watch the skies from anywhere on the planet.

Of course, it takes money to do that (and time) and right now, Astropotamus doesn’t quite have the money to set up a remote observatory. But it’s fun to think about all the things that he might put into it. Let’s see what that dream list might include, without going overboard on the Time Machine itself:

• Building roll-off roof observatory – $10,000, built by local contractors
• Pier-Tech 4 – 120V Electro-Mechanical Time Machine Pier – $6,500
• Meade LX400 20″ SCT Time Machine with Max Robotic Mount – $35,000 plus a lot of sweet sweet sweat setting it up
• Canon EOS-1Ds Mark III camera – $7,000
• Modified for astroimaging by removing IR/UV filters – $500
• Laptop for controlling things – let’s say $1,000
• Networking equipment – $250
• Heater (it’s cold in the desert at night under open skies) – $100
• Kuerig for hot chocolate – $100

That puts our total at $60,450, but we can probably chop a few bucks off here and there so let’s just call it $60,000. Or, according to realtor.com, a nice 4 bedroom, 2 bath 1500 square foot house on three-quarters of an acre near where Astropotamus currently lives. All so I can set it up, walk away, and use it from somewhere else.

New Mexico Sky - http://rascvic.zenfolio.com/p1028029664

Holy Crap!!!

If I’m spending 60 large on a Time Machine and mount and pier and building and a Kuerig with hot chocolate then I’m going to be there to use the damned thing! Maybe I can start by putting a lawn chair on the empty plot and just looking up at the dark New Mexico sky, dreaming of the day when I’ll have the biggest, most powerful Time Machine an Astropotamus has ever had…

Shortest post ever: No. Now, let’s take a closer look.

Celestial orbits are simple in one’s mind but complex in reality. Lots of things make our trip around the sun not quite perfect when you look closely at it. Plus, there’s that darned atmosphere. More about that in a moment. Let’s start with what an equinox is.

Latin for equal night (roughly translated), the equinox happens twice a year when the Earth make its tilted, elliptical way ’round the sun and occurs at the exact moment when, if you were standing on the equator, the sun would be exactly directly overhead. Then it’s gone. It happens for a brief moment and it’s over. This happens once in late March and six months later in late September.

There are lots of resources for learning about the equinox and how it’s defined and when it will be (the next time a fall equinox will be on September 21, the day most people think it is, will be 2092). You can go find them yourself. What I want to talk about is why we don’t see equal parts day and night. Oh, and why the equinox doesn’t make eggs stand on end.

“Day” is when the sun is visible with an unobstructed view of the horizon. Today, that’s mostly at sea on a calm day, but use your imagination and pretend there are no trees, buildings, or cell towers. If you stand in your yard (or street or tennis court or flight deck) and look at the eastern horizon in the morning, you will, on a cloudless day, eventually see the sun. But the sun is not a point of light. It’s a huge ball of gas and even from 93,000,000 miles away, it’s so big that it looks like it’s about the size of your pinky fingernail held at arm’s length (so does the moon, by the way, which is why we have total solar and lunar eclipses). So you’ll see a slice of the sun come up and get bigger and bigger, and when it goes down at nighttime in the west, you’ll see it get smaller and smaller until it shrinks to a sliver and then is gone.

So you see the sun for longer than it’s really “daytime” because the sun isn’t a point of light that’s “on” and then “off.” This is complicated by our old friend, the atmosphere. The same reason that the UARS satellite isn’t falling to Earth in a predictable fashion causes us to see the sun before it’s actually up over the horizon. This is called refraction and it’s is why light bends and makes rainbows, among other things. You’re actually able to see the sun before the sun rises, and depending on the size of the atmosphere (believe it or not, it gets bigger during solar activity [this is why UARS is not being predictable]), it can expand and contract, and thus refract more or less.

This is starting to make my head hurt. Luckily, there’s only a few more reasons why we don’t have equal days and nights on the equinoxes. The first is altitude. The higher you are, the sooner you’ll see the sun and the longer you’ll see the sun for on that day. Denver sees more sun than Kansas City, even though they’re about the same latitude, because Denver is a mile higher and can see the sun for a few minutes more each day than Kansas City does.

The last thing we’ll consider is latitude itself. This is how far up or down from the equator you are. Remember – the Earth is not round, it’s egg-shaped. As you get nearer to the poles, the diameter shrinks faster than if you were simply getting close to the “pole” of, say, a basketball. This causes the local curvature of the surface to be lesser or greater depending on where you are, which makes daylight longer or shorter as a result.

The only times that the length of day is equal to the length of night is actually a few days before the spring equinox and a few days after the fall equinox. This is called the equilux and occurs because there’s actually about 14 minutes more of sunlight on the fall equinox, so you have to wait a few days until the day shrinks enough to be equal to the night. The reverse is true in spring, so you have to catch it a few days early. The equilux also depends on what your latitude is and there are no equiluxes on the equator. Man, sometimes the simplest things can be so complex because of such esoteric things as egg-shaped planets.

Kids Balance Eggs

Oh, that reminds me. Do eggs stand up on their own on the equinox? Traditionally, this is done on the Spring Equinox, with raw eggs, as a symbol of rebirth and growth and blah blah blah. And yes, you can stand an egg on its end on the equinox. Really. You can! Try it! And then do it a week later. And then a month later. And then two months after that during the solstice. You’ll find it works every day, not just the equinox. You just have to have patience. It’s not weird science and it’s not gravitational alignment, it’s center of gravity and little, teensy-tiny bumps on the egg shell that cause it to be able to stand up on a smooth surface.

And if you’re having trouble getting your egg to stand up, it’s even easier on not-so-smooth surfaces. Failing that, put a little pile of salt down first, get your egg to stand up in it, and then gently blow the excess salt away. Take your picture now and have eggs Benedict later!

We have two things going on in September, 2011 that are not exactly rare, but they are things that you don’t get to experience more than a few times in a lifetime. The first is the explosion of a star in the Pinwheel Galaxy (M101) and the second is the crashing to Earth of the NASA UARS satellite. First things first – the supernova.

SN 2011fe is a medium sized star that went bang in the Pinwheel Galaxy. It’s only 20,000,000 light years from Earth, so about the time that Giraffes first put their necks up to the trees to eat the leaves at the top of the canopy, this star blew up. Its light has been racing towards us ever since. About a month ago, we got to see it. Or you did if you have a really good Time Machine.

M101 is so far away that it takes a Time Machine about twice as large as Astropotamus’s to be able to even see it. The supernova itself looks like any other middle-bright star in the night sky though my Time Machine. But I know better. There was no star there in July. Then there was one in August and September. Now it’s fading, just in time for the rain that’s coming over the next five nights or so. The Internet is full of information about the supernova, so I won’t pretend to tell you anything new here, but just keep in mind that a single star from a galaxy 1,900,000,000,000,000,000,000 kilometers away (damn, that’s far) briefly shown bright enough to look like a star only 5,700,000,000,000,000 kilometers away. Makes it feel positively close, doesn’t it?

I didn’t take this image, but it’s a good one to get an idea as to how bright the overall supernova is. Remember, in this image, all of the other dots that look like stars are stars that are no farther away than 25,000 light years. Most are more like 2500 light years or closer. The supernova is almost 8000 times farther away than any of the other stars, yet shines just as brightly. Look closely near the middle, about 1/3 from the bottom, and you’ll see two white lines that indicate where SN2011fe lies.

Moving from things 20,000,000 light years away to things less than 200 miles away, we come to the NASA UARS satellite. As I write this, it’s about 72 hours away from crashing into the planet, even though we’re still not quite sure where it will crash. It reminds me of when Skylab did something similar on July 12, 1979 – 4 days shy of the 10th anniversary of the launch of Apollo 11, which put men on the moon.

So far, no one has the unfortunate honor of being the first known human killed by falling man-made space debris, but there is often damage when things come crashing out of the sky. Skylab was a randomly moving, hulking piece of metal that was not under control when it crashed. It rained parts of itself down on Australia, putting charcoal sized pieces of supersonically heated debris through people’s roofs.

Mir Falls to Earth

Mir was another space station that came down, but it did so after Russian engineers gave it an intentional push with a rocket burn that caused it to go into a decaying orbit and land in the Indian Ocean. That was in March of 2001. And here we are 3800 days later getting ready for UARS to lumber out of the sky and fall…well, we don’t know.

It’s not falling in a controlled manner like Mir did. It’s more like Skylab. Luckily, it’s not quite as big. But it’s still expected to spew its debris over a 500 mile long track somewhere between 57 degrees North latitude and 57 degrees South latitude.

That’s roughly most of Canada, Greenland, Denmark, Sweeden, Latvia, all of the UK, the bottom half of Russia, and everything south until you get to the southern tip of South America. So, roughly speaking, every populated place on the planet is a potential space-based smash-em-up derby.

Actually, truth be told, NASA and NORAD, which track the 20,000 estimated pieces of space junk have a pretty good idea what the track of UARS is and where it will end up. You can see it at this web site. Pay attention to the yellow lines. That’s where the satellite will be during its presumed death plunge. Most likely, it will be off the coast of South America and shower a few llamas with debris. One of those tracks, however, shows it going right over Astropotamus’s neck of the woods so there’s a chance we’ll be in the fall zone.

Personally, I think the odds are more likely I’ll get killed by a radioactive rabid monkey, so I’m not too worried about it. But if a piece of of UARS junk hits my backyard, I’m going to go collect it and put it in a nice Lexan case on my mantle as a reminder of all the other things that have gone bang in the sky.

Electromagnetic Spectrum

Light is made up of photons.  So are radio waves, X-rays, gamma rays, infrared, and ultraviolet.  Together, this is known as the electromagnetic spectrum (or EM) and together, it makes up every possible type of electromagnetic radiation that there is, including most of which you can’t see with your eyes.

For most of the past two centuries, photography was designed to show other people what something looked like as if they were there.  So the process developed (no pun intended) over time to show the portion of the EM that our eyes respond to.  Some people thought it would be neat to see the world in infrared, but that was the main exception.

When scientific photography started, people realized that they could capture images using non-visible EM and shift it chemically (or more recently, with a computer) to the band of EM that we recognize as visible light.  These “false color” images are very popular in astroimaging, since a lot of what is sent out as radiation from distant objects is in the X-ray, infrared, ultraviolet, and radio portions of the EM spectrum, not in visible light.

So why is this important?  Well, photons are the vehicles that carry the EM information.  Let’s consider just visible light for a moment.  This is EM that’s traveling in wavelengths of about 380nm to 760nm.  Anything with a wavelength shorter than 380nm is in the ultraviolet range (or higher) and anything longer than 760nm is in the infrared (or radio).  We don’t see those, so we’ll ignore them for a minute.  To get the photon to carry a 400nm wavelength of light, for instance, it has to absorb just enough energy so that it vibrates at 7.5E14 Hertz.  That means it vibrates 750,000,000,000,000 times each second to produce a nice purple for you to see.

Okay, so photons carry light, or any EM radiation, by vibrating at ridiculously fast rates.  So what?  Eventually, a star or a nebula or a quasar or some object in space will radiate a photon towards Earth.  If we’re lucky, it will go in the end of our Time Machine and suddenly Astropotamus can see the star through they eyepiece and say “wow, that’s beautiful.”  Or better yet, since it’s starting to get cold outside, it can go onto the sensor of the camera connected to the Time Machine.

The sensor is a light sensitive device that detects when a photon of a certain wavelength hits it.  Do this a 12 million times, and you have a 12MP digital image.  Sensors detect all the light that hit them, but are only sensitive to certain ranges of EM radiation.  In the case of our DSLR, that’s visible light.  Or is it?

Remember I said that photography mostly developed (again, no pun intended) to provide the ability to show someone else what you saw?  You can’t see infrared, so why capture it on film?  Same for digital – you can’t see it, so why capture it?  Well, the sensor could capture it if it were allowed to capture it, but there is a filter in front of it that prevents it from doing so.  Same for ultraviolet.  So by design, we chop off the light that gets to the sensor so that it can only see what we can see.  This makes for great pictures of the cat but not so great ones of deep space objects that are shining all over the place in non-visible wavelengths of light.

So we can modify our camera to remove that filter and be able to see more of what there is to see.  This is generally a warranty-voiding activity and not for the feint of heart.  It also makes the camera next to useless for “normal” photography.  That’s why Astropotamuses usually use a camera for astroimaging that is dedicated to astroimaging.  It’s easier than explaining why everyone looks brown and the sky is orange when you take family portraits.

Later, we’ll discuss how we can take these images and align them, stack them, process them, and combine them to create the beautiful images you see here and from other astroimaging sources.

One night, while reading about the smell of the universe (or maybe it was the various mathematical models that let us figure out the mass of a sun a billion light years away, no wait – it was about all the names for objects that astronomers have come up with over the years – things like quasars and blazars and neutron stars and so forth), she interrupted me and said,

There sure is a lot to look at up there.

Such a simple statement, yet it almost brought tears to my eyes.  She’s right of course, and we use Time Machines to look at all that stuff and figure out what it’s all about.  Some of our Time Machines use visible light, some use infrared, ultraviolet, or radio and even X-rays.  But they all work the same way – aim it at something and you see what it looked like a second or minute or year or centuries ago.  Which is why sometimes it’s fun to be in the present.

Moonlight through the leaves

Sometimes, rather than hoping for a clear night of seeing and lots of stars or nebulae or other deep space objects to look at; sometimes when the moon is out but it’s too hot to get the Time Machine out and set it up; sometimes, it’s just nice to look at something, see it, and appreciate it.

That’s what this image is all about:  appreciating the moon through the trees near our pond in twilight.  No special exposure, no stacking or slicing or multiple images.  No computer correction (except for cropping and resizing).  No nothing except a tripod, a camera, me, and what you see here.  I hope you appreciate it just like I do.

I also like to see Mrs. Astropotamus and look at her and appreciate her as well.  We were traveling recently, and we didn’t have any magazines.  But I did have my tablet computer and access to astropotamus.com, so I read her some posts from here.  She was tired and trying not to fall asleep, but she was awake enough to ask questions and be interested in what I had written.

At one point, she said, “you are amazing.”  I may have misheard her, but I’m pretty sure she called me amazing.  Later, she told me that she was really impressed with what astropotamus.com contained, what I’d written, and suggested some changes to make it even better.

Between you and me, it’s things like that that make me love her even more than the stars above.