Personal Panoramic History, Part 5: 2012

The previous post in this series (covering 2011) had quite a lot pictures, but for whatever reason 2012 was a pretty slow year in the panorama department. I think part of it was that I was working at the Visitor Information Station on Mauna Kea for most of that year, which was also the year the transit of Venus happened. I was pretty quite preparing for it and then recovering from it afterwards, and it seems to have translated into fewer photo opportunities.

In January 2012 I got my first smartphone (a Samsung Galaxy S2), and with it my first automatic panorama creation ability. I didn't actually use it much because it was still pretty poor in those early Android versions, but I've got a few panoramas made using it from this year and we'll see more in the future.

April

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My first panoramas of the year don't come until April, but they come from the one time (so far…) that I've hiked Mauna Loa. And just as while hiking Mauna Kea I got pictures of Mauna Loa, so while hiking the latter I turned north to get pictures of the former.

Mauna Kea from the south.

Hualālai and Mauna Kea

 These two pictures are both from where the trailhead starts, just outside of the Mauna Loa Observatory entrance at 11,141 ft (3,397 m). The first one is a zoom-in on Mauna Kea, while the second is a much wider field view covering a bit less than ~180°, showing the Mauna Loa access road on the right and the start of the trail on the left.

Mauna Loa summit caldera.

Mauna Loa is so flat that while climbing it there isn't much to get panoramas of other than Mauna Kea, until you reach the summit caldera, Moku‘aweoweo. This panorama is still pretty cool to me, even if we didn't make it to Mauna Loa's summit that day, as it's technically the only time in my life I've been inside the caldera of an active volcano! (Even if it did last erupt in 1984…) You can see the sides of the caldera on the sides of the photo, as I climbed down just inside the rim (which was maybe three meters deep). I don't think this is a particularly great panorama, but it's special to me due to the circumstances surrounding its creation.

June

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Venus transiting before the Sun.

In June the latest transit of Venus (last one until 2117!) happened. This panorama is hand-made, as I couldn't get Hugin to make one for me using my photos. It's not really meant for astronomical panoramas and the photos aren't particularly well-focused either, so it's understandable that it failed to make anything of them.

August

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I didn't get around to making any more panoramas until August due to recuperating after the transit of Venus, and when I did I ended up taking my first auto-generated panoramas with my phone due to (as usual) my camera battery turning out to be dead. I was able to get a tour (I think with the University Astrophysics Club) of the Very Long Baseline Array dish on Mauna Kea, and it turned out to be a great panorama subject.

These early auto-generated panoramas are really ugly however, so I'm only going to show one to give an idea. I've got a few more, but I just don't feel like displaying them here; that early panorama creation software was pretty rough and the resulting images are not easy on the eyes. I did put two additional panoramas from this trip up in my original post about it, so you can follow the link if you really want to see more early auto-panorama creation eye-sores.

This is the dish of the VLBA telescope, from near it's rim. Which is about ten stories above the ground, by the way. I'm actually amazed the camera was able to get such a good contrast, considering the blinding whiteness of the dish.

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And that's actually it for panoramas from 2012! In October I did lava tube spelunking for the first time and got some cool pictures, but lava tubes unfortunately don't make great panorama vistas. As the end of the year approached I was starting to get pretty burnt out at my job as the Visitor Information Station; I discovered that there's a vast difference between doing something as a volunteer because you love it, and doing it because you get paid to do it. On a whim I applied to a job with the James Clerk Maxwell Telescope that only required a Bachelor's degree, and near the end of November got a call saying I was being offered the job, which opened up a whole new chapter of my life. But that's for the next post! A hui hou!

Volunteer Reward Pins

Saturday night was the annual Volunteer Appreciation Banquet that the VIS puts on every year and which I was able to attend for my volunteering experience prior to becoming employed. Every year the banquet recognizes all the volunteers who have volunteered at least 25 hours over the past fiscal year, along with special awards and recognition for those who go above and beyond in their efforts. This is my fourth time attending and marks my third year coming up Mauna Kea, as my very first time volunteering was on the night of banquet in 2009.

This year we have what I hope will catch on as a new reward in the form of little pins for the hats we give volunteers who have enough hours to attend the banquet. The idea was thought up jointly between me and one of my co-workers, who happened to be in charge of the banquet this year. Since she was actually an art major before switching to astronomy she designed the pins and I hand-copied them on the computer using Inkscape to get them in a digital format where we could have them printed on pins.

Anyway, we weren't able to get too many of them physically created for the banquet (we hope to have them more fully realized next year), but I thought I'd share some of the pictures with you. When I get time I'll try to post some pictures of the pins that we did manage to get printed.

These, as you can probably guess, are for the number of volunteer hours people contributed per year. Five hundred and above are pretty rare; I think we had three people this year who had a thousand hours, all of them retired and able to come up frequently.

This one's for volunteering to do a summit tour. I really like the quiet, majestic look it has.

This one's for attending the banquet this year. I had a lot of freedom in choosing the font when converting my co-worker's hand-drawn designs to digital images, and I think this one came out nicely.

This is for participating in a trail maintenance operation, where we hike down the summit trail from the top of Mauna Kea to the VIS picking up trash along the way. Originally we had a different, much more detailed picture for this one, but when we got the first batch of physical pins in we realized that it wouldn't translate well (the pins are smaller than these pictures appear on the screen). My co-worker didn't have time to come up with a new design, so this is the only pin that I actually designed myself. I'm pleasantly surprised with how well it came out, actually.

And, this one's for the transit of Venus, naturally. Simple and elegant.

Edit (10/18/12): And here's a picture of the first four pins that I found on my phone:

Image Stretch and the Effects Thereof

Today I just want to briefly discuss a very important decision that went into making the transit of Venus video I posted last time. That decision was how to stretch the images from the CCD camera. You see, the CCD camera has a wide range of sensitivity, with 65,536 different light levels it can record. Most monitors cannot display anywhere near this amount of contrast, so the image has to have that range compressed down into what the monitor can display. In theory, this means that a lot of detail is going to be lost, and that's where stretching comes into play.

Stretching an image's histogram basically means reassigning how the compression takes place. When you're looking at an astrophoto, you may have 65,536 different levels of brightness, but a large number of those are probably going to be so close to black as no matter. You can then adjust the stretch so that they simply display as black, leaving more of the dynamic range of the monitor available for seeing detail in the brighter regions. Essentially, the image stretch lets you decide which regions of the image you want to see detail in based on their brightness.

To illustrate how important the stretch is, let me give you some examples. Immediately upon applying the reduction process to one of the images of the transit and importing it into GIMP, we get this picture:

To the left you can see the Sun with Venus in front of it and a few sunspots visible near the middle of the disk. On the right you can see the default linear stretch currently applied to the image. Basically, it maps a zero value in the image to black, a value of 65,535 to white, and linearly compresses everything in between. The horizontal scale is the brightness levels of the original image, the vertical scale is the brightness levels on the monitor, and the gray lines are a histogram representing how many pixels there are at each brightness level. What it tells us is that this image has a lot of very dark pixels (on the left, all the background), a lot of very bright pixels (on the right, the center of the Sun's disk) and a moderate number in between (around the edge of the Sun, and things like sunspots).

Speaking of sunspots, I quickly discovered that there were more than could be seen with just the default linear stretch. By cutting off the left end of the histogram pretty dramatically with another linear stretch, I could bring out details as yet unseen:

In some ways, this worked quite well – sunspots had much better definition, and you could see more of them. The main problem to me was that it made the outside edge of the Sun look a bit grainy. I ultimately decided that it was not quite good enough, and continued looking for a suitable stretch. My next attempt, which I'm calling an “exponential” stretch, looked like this:

This stretch is similar to the previous linear stretch, but leaves more detail in the dark areas. Again, the sunspots looked good, but it looked even worse around the edges than before. After playing around with variations on both of these (plus several others), I finally came up with the curve that I would end up using:

This curve is, ultimately, a compromise. It doesn't show the sunspots quite as well as either of the previous curves, but it looks much better along the edges (at least it does at 100% magnification, they all look about the same in these pictures). It took me quite a while to decide on this curve, because I'd keep looking at it and tweaking it and trying to get the absolute best curve possible, especially since I was going to be applying it to the next one hundred and eighty-seven images and didn't want to have to go back and redo it. It wasn't a decision lightly made, I'll say that much.

I also see that, having sat down to write a “brief” blog post, I managed to write a 650-word essay. I don't know why that always seems to happen. I hope you at least found it interesting. I've come to appreciate the image stretch more and more as I (hopefully) get better as an astrophotographer, and it should show in some of my upcoming pictures. A hui hou!

Transit of Venus Video (At Long Last!)

Well, I have finally recovered enough from the wonderful back-to-back combination of virulent head-cold and raging sunburn to finish my long-promised video of the transit of Venus. And it only took me over a month.

First, a quick explanation: this video does not show the beginning or end of the transit. The beginning I didn't catch because I had other duties to attend to which prevented me from getting set up in time, and when I finally did I had some unexpected problems focusing. Because of this, the video doesn't start until 2:26 PM, almost two and a half hours after the transit started. The ended wasn't captured because it wasn't visible from my location, as the Sun set behind hills to west. The last frame I captured was at 6:00 PM, about 40 minutes before the transit ended. In between I took a shot every minute, for a total of 188 frames. With that said, enjoy.

Edit (1/13/2018): Remaking and re-releasing videos seems to be all the rage these days, so I thought I'd join the fun! Actually, I was reminded of this video a while back and after watching it was dissatisfied with the quality—this was years before I started seriously pursuing video editing, and was made in Windows Movie Maker. Plus now that I've got a YouTube channel it can reside there instead of relying on Blogger's somewhat shaky video hosting abilities.

Venus Transit T-shirt Concept Art!

I don't know about you, but I often find it quite interesting to get behind-the-scenes looks at how things are made. My analytical mind is constantly analyzing everything I see (even when I'm not consciously aware of it), trying to find out what makes good things successful, and why unsuccessful things fail. In that vein, concept art is a very useful learning tool. Seeing what was kept and what was dropped helps in understanding the thought that went into the creative process, which is very interesting for a creative person like me.

Having said that, I'm rather happy to be able to unveil some of the first pieces of concept art ever on this blog. This one is an alternate design for the transit of Venus T-shirt that was rejected (with good reason) because it didn't stand out very well. I was trying to imitate the appearance of a solar flare with a picture I took of the Sun through our solar telescope last year, an idea I had only just come up with.

Concept art for the transit of Venus T-shirt. I hadn't even put a simulated Venus on yet, and this was before we ditched the photo of Mauna Kea for a more stylized approach.

I thought at the time (and still do) that this was a really cool way of making lettering, but I also see why it wouldn't have made a good poster. It's fairly ethereal, and doesn't really stick out much. Also, it's rather time-consuming to make each individual letter, though to be fair I did spend a good amount of time placing and adding a separate gradient to each letter in the official "Transit Of Venus" header that ended up on the poster. (Notice how I'm analyzing my own work now? Told you I'm constantly doing it.)

All in all I still think it's a neat design, and I'll be filing away the idea in case I ever need to use it again some time. (The secret to it, by the way, is nothing more than repeated applications of the Smudge tool in GIMP.)

Transit of Venus Redux

Well, the transit of Venus came and went, and I survived. I wasn't entirely sure I would with all the stress building up to it, but here I am. I've been quite fortunate in getting four days off in a row to recuperate, and I felt rested enough by the third day to finally make myself the belated birthday cake that I've been meaning to do for two weeks now.

I also recovered enough of my creative drive to put together this collage from pictures I took with my camera through one of our 14-inch scopes. This picture was taken around 3:37 in the afternoon, and you can clearly see Venus as the round dot and a couple of sunspots as the irregular faint black spots.

Transit of Venus, June 5, 2012.

It's kind of strange to consider, but this is now a rather historic picture. I can't really say that I've ever done anything historic before. Making some assumptions about the future, it's possible that someone over a hundred years from now could find this picture while researching ancient coverage of previous transits of Venus. Kinda makes you stop and think, doesn't it?

To paraphrase a famous quote from the previous pair of transits, “And what will be the state of science in that far distant future when the December snows are falling in 2117, God only knows.”

Transit of Venus Posters!

Well, today, the last day before the transit of Venus, I thought I'd share these poster designs that I came up with for work and which are now available as actual 11” by 17” posters in the gift store at the Visitor Information Station. Essentially the same poster but in two different color versions!

On the Scientific Value of the Transit of Venus

Well, this is it. On Tuesday Venus will pass in front of the Sun, along with everything that entails for my job of trying to present it to the public. To be honest, I'm most excited simply that it will be over, so life can return to a semblance of normality and not crazy over-working (I was originally scheduled to work 64 hours this week over a period of 5 days, until I was able to point out that for 2 of those days I was redundant and unnecessary).

Today I thought I'd quickly explain why previous transits of Venus were such objects of scientific interest, to the point that multiple nations sent scientific expeditions on hazardous voyages around the world. It all has to do with the size of the Solar System

Back in the early 1600's a brilliant astronomer by the name of Johannes Kepler formulated three descriptions of planetary motion that have come to be known as Kepler's Laws. A full description of them would take another post, so it will suffice to say that they describe planetary motion in the Solar System to a very high degree of accuracy (one made even better when Newton introduced his theory of gravity to explain why the laws worked the way they did). The third law, in particular, relates the square of the time it takes a planet to orbit the Sun to the cube of the semi-major axis of its orbit. To a good approximation, given that all planetary orbits are pretty close to circles, what this says is that if you know the orbital period of a planet, you can figure out how far it is from the Sun. Figuring out the orbital period is a bit of work, but nothing that the astronomers of the day couldn't handle, and they were excited to find out just how big this Solar System of ours is.

Unfortunately, there's one catch: the way the law is formulated gives the distance from the Sun to the planets in terms of the distance between the Sun and the Earth. Since that wasn't known to begin with (that's part of the reason for wanting to find it, after all), it seemed that astronomers were stuck (sure, they could use the law to say that Jupiter is 5.204 times farther from the Sun than Earth is, but without absolute numbers it's a somewhat hollow achievement).

This sorry state of affairs remained until a Scottish mathematician named James Gregory suggested that observations of the time taken for Mercury to cross the Sun's face as seen from widely separated points on Earth could be used to figure out how far away the Sun was. The young astronomer Edmond Halley (better known for being the first person to predict the return of a comet, which still bears his name) tried to do this for a transit of Mercury in 1676 but was frustrated by the fact that only one other such observation existed, and didn't think that two data points were accurate enough. He suggested that more accurate calculations could be done using a transit of Venus instead, but he unfortunately would not live to see the next one in 1761.

His suggestion, however, did not go unheard (being the second Astronomer Royal to the British crown may have had something to do with it), and when the next pair of transits rolled around astronomers around the world were ready. Expeditions from England, France, and Austria traveled around the world for the 1761 transit, and Captain Cook made his first voyage to the Pacific to observe the 1769 one.

This was, in a very real sense, the first major example of international co-operation in history. It's something we don't even think about today, but it helped set the stage for the atmosphere of cordial co-operation that exists in science throughout the world today (with the occasional bit of friendly rivalry thrown in). We don't find it strange today that scientists from all over the world freely publish the results of their experiments which may have required millions of dollars and hundreds of man-hours to find, but it didn't necessarily have to be this way. Science and knowledge could have been (and have been at points in history) very territorial things, hoarded for national gain (think of the secrets of Greek fire, known only to the Byzantines). Instead we have a world where anyone can pick up the latest issue of a scientific journal and peruse its contents freely (in the sense of “personal freedom”, not the “no-cost” sense), and I like to think that astronomers may have had something to with that.

To cut a long story short, the expeditions, although many of them did observe Venus, were not successful in their main quest to determine the Earth-Sun distance. The reason has to do with the “black drop effect”, wherein Venus appears to elongate as it approaches the edge of the Sun's disk (from either side). Unfortunately, precise timing of exactly those moments was the critical information needed for the calculations to work. This effect was at first (and for a long time) thought to be proof that Venus had a atmosphere, but in reality it has more to do with imperfections in observing equipment and turbulence in Earth's atmosphere (Venus does have an atmosphere, of course, but that's beside the point, as the black drop effect also shows up during transits of atmosphere-less Mercury to a lesser extant).

Anyway, when the transits of 1874 and 1882 came around, astronomers tried again. Although the black drop effect was still in, well, effect, the data generated from all previous observations was enough to get a pretty good value of 149.59 million kilometers (92.95 million miles) using statistical methods, very close to the modern day value of 149,598,261 kilometers (92,956,048.8 miles).

And where are we today? With the advent of radar and other modern advances we can now calculate the distance to the Sun to about \(\pm\)30 meters (~100 feet), and transits of Venus are no longer necessary to tell us how big the Solar System is. They are now interesting for entirely new reasons that could hardly have been foreseen by those astronomers of old. Now, observations of transits of Venus have the potential to help with the burgeoning field of finding planets around other Stars, especially small, rocky planets like Earth and Venus.

At this point, it's interesting to speculate on what may happen between now and the next transit of Venus in 2117. Given how much the world has changed in the last 130 years, I don't think I want to make any predictions, but it would be interesting to see how our knowledge of exoplanets will grow in the meantime, and how much can be learned from studying this current pair of transits. Exciting stuff!

Earth-Venus Conjunction Explanation

I've previously mentioned the upcoming transit of Venus, and said I'd write more about it, then completely forgot about it. So tonight I'd like to rectify that by writing a bit more about these amazing events. Looking back at my previous post I see two things that I specifically mentioned talking about: further details of how Earth's and Venus's orbits interact, and more about why transits of Venus are scientifically important.

As I wrote in my earlier post, transits of Venus happen at what appear to be – at first glance – rather strange intervals. Specifically, in the present era, transits happen in pairs 8 years apart, separated by intervals of either 105.5 or 121.5 years. The reason this happens has to do with the shape and orientation of the orbits of Earth and Venus. In the picture I put together below, the orbits of Earth and Venus are shown at the correct scale relative to the Sun and each other. Earth's orbit is green, and Venus's is blue. Venus and Earth themselves are too small to be seen at this scale. One point of terminology: the point when Venus passes Earth in its orbits is called its conjunction.

Although the angle between Earth and Venus's orbits is only 3.4°, you can see in the top half of the picture that most of the time Venus passes above or below the Sun at its conjunction (when it passes us in its orbit). The only time we can actually see it cross the face of the Sun is when both planets are close to what is called the line of nodes of their orbits. This is where their orbits cross as seen from edge on (as seen in the top half), and is denoted by the dashed red line in the lower half of the picture. The location of Venus's conjunction, however, is not fixed, but moves slowly backwards around the orbit over time. Whenever it happens within a narrow region around the line of nodes, a transit of Venus is seen.

Because of the arrangement of their orbits, 8 Earth years are almost exactly equal to 13 Venus years (with a difference of just 0.4 days). That is, each 8 years Earth and Venus are in almost exactly the same position relative to each other, just rotated slightly along their respective orbits. Thus, two transits of Venus can happen 8 years apart within the narrow region around the line of nodes, but the region is narrow enough that adjacent conjunctions result in Venus passing above or below the Sun as seen from Earth. Currently Earth reaches the line of nodes in June and December, so transits occur in pairs with one in December (such as the 2004 transit) and one in June (this one).

But why the 105.5 and 121.5 year intervals between transit pairs? That results from the fact that neither Earth's nor Venus's orbits are perfectly round (although Venus's orbit does have the lowest eccentricity of all the planets). Because of this fact, the rate that the Earth-Venus conjunction moves is not constant, and also has a different distance to move. This difference causes the difference in duration between pairs.

Hopefully the preceding explanation has helped you better understand what's going on. I'm going to defer the explanation of the scientific value of a transit for a later post as this one is getting pretty long and I need to get to bed. I also hope to show you the designs for the posters for the transit of Venus that I created, which have now been printed and are actually on sale for a limited time around the transit!

Daniel Berke and the Transit of Venus

I've let a few hints slip in some of my previous posts of a big event happening this summer, something called a “transit of Venus”. Given that as of the 5th we are only two months away from the big event, I'm going to kick off a series of posts about the subject from now till then.

First of all, you're probably wondering, what is a transit of Venus, and why is it such a big event? To start with, a transit in astronomical terms is when one object passes in front of another, and the transit of Venus is when Venus will pass in front of the face of Sun as seen from Earth.

Ok, you may be thinking, but why is it such a big deal? The answers is that transits of Venus are rare. Venus goes around the Sun in 224.65 days compared to Earth's 365.26 days, so Venus actually passes between the Earth and the Sun every 584 days, on average. If Venus actually crossed the Sun's disk every time every time this happened, they'd be about on par with total solar eclipses in rarity.

But they don't. Because of the way the orbits of Venus and Earth are aligned, Venus normally passes above or below the Sun as seen from Earth. It works out that transits of Venus only happen in pairs eight years apart, with either 105.5 or 121.5 years between pairs. The specifics of why this happens are fascinating, and something I'll go over in greater detail in a later post.

Anyway, because of their rarity, only six transits of Venus have ever been observed since the invention of the telescope over four hundred years ago: one in 1639, a pair in 1761 and 1769, a pair in 1874 and 1882, and one in 2004. But it's not just their rarity that makes them interesting. With the right measurements, a transit of Venus can be used to figure out the distance from the Earth to the Sun. Back in the 18th and 19th century, this was big news, because that distance was unknown at the time.

In fact, it was such big news that it sparked one of the first examples of international scientific collaboration on a significant scale. Dozens of expeditions were dispatched by quite a few countries to every corner of the globe in order to get as many different measurements as possible (I'll explain why it was necessary to get widely separated observations in a later post). Indeed, Captain Cook, whose third voyage made him the first European to discover Hawaiʻi, first traveled to the South Pacific (Tahiti to be specific) in charge of one such expedition.

If you've been paying attention to the numbers, you'll realize that since the last transit was in 2004, the next one won't be until 2117, so this is the last one to be seen in our lifetimes. It's also going to be visible in its entirety from Hawaiʻi, so we are expecting major crowds at the Mauna Kea Visitor Information Station where I work. While I'm excited that many people will get to see this historic event – and who knows what future great astronomers may be inspired by seeing it? – I'm also starting to feel a little overwhelmed due to the enormous number of things that need to be put in place for it to happen.

To that end I decided to put together a little humorous poster to help take my mind off all the stuff I need to get done. One of the things I'll be doing for my job in the immediate future is creating designs for a set of limited edition “Transit of Venus” T-shirts we'll be selling on The Big Day. I'm enjoying this assignment because I enjoy making astronomical art, and the stuff I've been coming up with inspired me to create this:

(Click for full size.)

I also have some prototypes of possible shirt designs done at this point in a similar vein, but I'm going to hold off on posting them till we figure out what we want to use for the official shirt. I do have some concept art for the title you can see though.

Anyway, look forward to future posts where I go over more of the fascinating science and history associated with transits of Venus. A hui hou!