My First ISS Photo

By Nathan | March 6, 2010

I've never actually tried to take a picture of the International Space Station before. I have a camera and a tripod and the time, but for some reason I never got around to it. That changed when I heard that there would be a pretty good sighting in Portland tonight.

I set up my camera (a Nikon D80, if you're curious) in the backyard, took some test photos then waited. Waiting for the pass was a little surreal because I was watching the ISS slowly circle the earth on my iPod. As the minutes ticked by I saw a little animated dot draw closer and closer on the screen in my hand, knowing that dot represented 5 human beings madly circling the Earth at over 17,000 miles per hour. Right on cue a fine dot appeared — not on a screen — but in the sky. I pressed the shutter release and watched joyfully as the bright point of light streaked across the sky.

Something about space, about people leaving this planet, to learn, to experiment, or even if for no other reason than because they can, excites me like little else. And finally I captured a little piece of that excitement for myself in a photograph.

The ISS From My Backyard

The faint streak in the bottom third of the photo is the space station, faithfully orbiting the earth every 90 minutes. (click for a larger version)

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Space Shuttle Mystery

By Nathan | February 15, 2010

Last week space shuttle Endeavour launched on a mission to add one of the last pieces of the International Space Station. It was one of the last space shuttle launches and likely the last ever night launches. Among the people watching the launch was James Vernacotola who had his camera ready and waiting on a bridge in Ponte Vedra, Florida, about 115 miles north of the launch pad. He opened the shutter for a little over two minutes and captured this stunning time lapse photo of the launch.

Night time Space Shuttle Launch

Night time Space Shuttle Launch © James Vernacotola

Now, I think I know a thing or two about shuttle launches. I was looking at how the bright glow of the solid rocket boosters faded as they ate up their fuel and as the shuttle gets further and further away. But, hold on, about two thirds through the flight the glow appears to get brighter again. Quite a bit brighter really. And the color changes slightly. I had no idea why. So I set to find out. The fist thing I did was ask the internet via twitter, bu no one responded with an explanation that made sense. I was theorizing with my friend and astronomy lab teacher extraordinaire Adam and we came up with a couple of ideas. Perhaps the shuttle rolled so that the engines came into view better? Or maybe it was just a trick of the clouds reflecting more of the light? Perhaps it was the engines throttling up after breaking through most of the atmosphere? We had theories, but how to test them?

The first thing I did was to rule out the effect being an artifact. So I looked up other time lapse photos of other night launches. Lo and behold, the same brightening happens in all of the launches! It's far to unlikely that the same pattern if it were an artifact would happen during different launches at different times of the night seen from different angles from different cameras, so the phenomenon must be real. Which one of the explanations would it be? After debating the various likelihoods of our theories Adam pointed out that simply knowing when the brightening was happening would tell us a lot.

To figure out the timing I had do some work. Since I knew the exact place where the photo was taken I knew I should be able to recreate the scene in Google Earth. Hopefully this would tell me something. But first I need info on the launch. Luckily a company specializing in space system tracking already posted a path of the launch! But it was missing the times. So I took a time table augmented with latitude, longitude and altitude and wrote a script in python to add points to the Google Earth track.

STS-130 Launch from Google Earth

STS-130 Launch from Google Earth

Each point is about 5 seconds apart. What does this tell us about the launch? If I take the info from Google Earth and overlay it on the original I found that out of our two main theories neither could be correct! In fact the brightening happens after SRB burnout and separation! (and long, long after the roll maneuver)

Night shuttle launch labeled

The labeled image © James Vernacotola

Maybe my analysis was wrong? To double check I did the same Google Earth trick to a an image of another launch and found the exact same thing. It brightens a few seconds after SRB separation. This is also supported by the coloring. As the SRB's burn out the predominate color goes from orange (from the solid fuel of the boosters) to blue (from the hydrogen burning shuttle engines). The question remains why it get brighter. I'm still not entirely sure, but the SRB's continue to burn and spew exhaust gases after separation. They also tumble and spin. Perhaps slowing down and tumbling is enough to make them look brighter. Also during separation small ullage motors are burned to move the SRB's away from the space shuttle. But they only burn for a second and I could not explain why it gets brighter later and for so long. Unless anyone can come up with a better answer I am going to bet the tumbling of the SRB's is primarily responsible for the effect.

P.S. If you look carefully at the end of the photo you can see the space shuttle and SRB's as different lines!

Space Shuttle and SRB's in different tragectories

Space Shuttle and SRB's in different tragectories

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Maps of the Sky

By Nathan | January 23, 2010

The other day I came across a very awesome graph of the entire universe. It shows more-or-less every object in space we know about on a logarithmic scale from the center of the earth to the edge of the visible universe. It got me thinking about what you can do with large datasets so I decided to play around a little with the tycho-2 catalog. This is a famous catalog in the astronomy world. It contains the position and brightness and some other information of more than 2.5 million stars. That's about 99% of all the stars brighter than 11th magnitude (about 100 times fainter than what you can see with the naked eye!).

I used processing.org as my programming language and wrote a short piece of code to parse through the giant 2,539,913 line datafile and draw a pixel for every star with the brightness of the pixel based on the brightness of the star. And it looked pretty cool. But there was more work to be done. I wanted to use the color information in the catalog to make a color picture of the sky. This is not as straightforward as it might seem. The tycho-2 catalog has the relative brightness of each star measured using a standard blue filter (B) and a standard green filter (V — for historical reasons). Somehow I had to turn that into a color for a computer screen. Luckily a lot of the hard work has been done for me! I found a person who had already worked out screen colors for stars! All I had to do was write a function to approximate a screen color for a given color index (B-V). Sure made that sound easy didn't I?

Color Index

Color Index

Now I can map the sky with all the stars and their color and brightness. It looks something like this:

A map of the sky from the tycho-2 catalog.

A map of the sky from the tycho-2 catalog.

The bright snake-y thing is the milky way. Since we are in the middle of a galaxy when we look through the plane of galaxy we see most of the other stars in that same plane. Think about standing in the middle of a giant disk of dust, if you look straight up you see out of the disk and through a small amount of dust, but if you look right into the disk you see all the dust in a thick cloud. This is the milky way. The dark patches are clouds of gas thick enough to obscure the stars behind them.

The reason it looks like a curve in this picture is because I printed it in equatorial coordinates. These are sky coordinates based on the earth. The middle of the image is directly overhead the equator and the top and bottom are the North and South poles respectively. The milky way is a straight line in the sky, but if you unwrap a spherical map to rectangular coordinates you get all kind of distortion. As an alternative I can also make a map in galactic coordinates. These are coordinates locked to the milky way itself and looks like this:

Map of the sky in calactic coordinates.

Map of the sky in galactic coordinates.

I'm not sure what to do with these pictures but I am surprised how easy it was to make. I am thinking of other large datasets that might be interesting to play with. Any suggestions?

Here are the full size images and the code I used to make them:

If you would like to use the images feel free (this site is published under Creative Commons), drop me a line if you use them for something cool!

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Time Lapse from Mt Tabor

By Nathan | December 22, 2009

I like my camera as much as the next guy, but it's missing a feature: an intervalometer. An intervalometer is a device or program that lets you take a series of pictures in a row at some interval. This lets you do, among other things, time lapse videos.

So like a good nerd I hacked one together using an arduino. It's about as simple as it gets. In my circuit I used an infrared LED and that's it (Sure I should have added a current limiting resistor, but I like throwing caution to the wind sometimes). I found online someone who already figured out the blink code to trigger a shutter release. I used his code and that was it!

To test it I took it up to the top of Mt. Tabor and snapped off a 8 second exposures continuously for almost an hour. Later I took the results and used blender to stitch them into a video. And here it is!

Portland at Night from Nathan Bergey on Vimeo.

Notice that I caught the Hawthorne Bridge going up for a passing ship! Totally by accident.

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Looking Back at Gnomedex

By Nathan | September 8, 2009

I was lucky enough this year to have the most awesome experience of attending my first Gnomedex. Gnomedex is the self-described “Technology Conference of Inspiration and Influence” that meets yearly in Seattle, WA. It's a bunch of blogger, new media, tech enthusiast types that get together to discuss the society and the Internet. It may sound like a bunch of geeks, but this would only be partially true. Yes there was plenty of talk about gadgets and websites, but it all came back to community and how technology affects everyone.

Gnomedex is a relatively small conference, usually just a couple hundred people. Small as it may be, this group of people tends toward the amazing. Even though a lot people already knew each other through things like twitter, getting to meet in person still is important. After-party conversations ranged from how to build business models off of twitter to rapid prototyping circuit boards. The one constant was the quality of the conversation. In the real world, just like on the web, content is king.

Good Content

I was most interested in two particular talks at Gnomedex. One by a long time role-model of mine Dr. Phil Plait—otherwise known as the BadAstronomer.

The Bad Astronomer

The Bad Astronomer

Phil gave an awesome talk about skepticism on-line and the misinformation we are up against. News can spread so fast now that there is practically no firewall between the public and bad information. His archetypal example was a particularly bright meteor that was caught on camera, coincidently, a couple of days after a widely reported collision of two satellites in space. Almost immediately the Internet (well okay, just twitter) was abuzz with speculation that the meteor was a piece of the former spacecraft falling to the ground. Never mind that it happened at the wrong time of day in the wrong location and was moving far too fast. The rumor that it was a spacecraft quickly became ‘fact.’

This misinformation could be avoided if people are careful and ask questions about the evidence they're presented. Which is his point about skepticism. It's not really about being cynical or mistrusting but instead simply double checking the things you hear. Whether it's from wikipedia or from your family doctor, people can be wrong. And sometimes the wrong info can be dangerous.

Phil has been especially concerned about the growing influence of so called “antivaxxers.” These are people who are using their influence to convince—likely because they themselves believe it—people that vaccines are dangerous and lead to maladies such as autism. There are thousands of parents who believe this and it's extremely unfortunate because there is absolutely no link whatsoever! The real danger lies in not getting kids vaccinated. Suddenly there are cases of measles and polio and other diseases thought to be more or less eradicated showing up again in these un-vaccinated children. Some have died. The lesson here is to fight back. Misinformation is best kept at bay through constant vigilance—speaking out on the behalf of truth in letters to news programs, forum posts, or anywhere else you see questionable content.

Bre Pettis and his amazing MakerBot

Bre Pettis and his amazing MakerBot

Another talk was given the same day by a master of the modern DIY movement, Bre Pettis. Bre Pettis makes things. He is an amazing guy who has an uncanny ability to both consistently come up with great ideas and to follow through on them. He helped start NYC resistor, a group that makes cool things in New York and is the founder of MakerBot. MakerBot is an awesome open source 3D printer. 3D printers are great, instead of paper they print things. MakerBot extrudes ABS plastic and makes it into whatever shape you can imagine. It's like your own mini factory!

Something amazing happed when people were given access to 3D printers. A whole community sprung up around sharing digital files, just one step from being real things. One website in particular has emerged, called thingverse.

“People still haven't figured out that sharing is the best thing ever”

Bre talked about the amazing things that can happen when large sets of data are shared like that. Objects evolve, people add and refine designs and the end product is almost always better than it started. Historically design has been such a closed concept, with individuals and companies holding their cards close to their chest until the final product was unveiled. But it doesn't have to be this way. Open source is just as strong as ever and wonderful things happen when people collaborate.

Showing Up Counts

I didn't realize it until I got back to Portland and had some time to think about it, but the most interesting thing about all the people at Gnomedex is they all wanted to be there. I figured that I would be more of a spectator, happy to watch and maybe learn a thing or two. But really everyone is there to learn from each other and be a part of something. All you need to do is show up. I encourage anyone who likes talking about the internet or technology to go to Gnomedex next year and see who you meet. It's a great conference.

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