Comet ISON is Coming!

Comet ISON is Coming!

Get ready everyone! Comet ISON is approaching the Sun, and is expected to be visible in the pre-dawn sky as early as this weekend. Check back with us for all things Comet ISON: comet updates, photography tips, and more. Don’t forget to come visit LASM to view “Vagabonds of the Solar System: Comets Past and Present” exhibition opens November 19th!

Antique Jewelry Inspired by Comet Halley

As part of our upcoming comet exhibition at LASM, the museum acquired a collection of very interesting pieces of jewelry.  The staff and I are quite fascinated by them. Their simple design is easily overlooked at an antique store if one isn’t familiar with the style. I will definitely be on the look out next time I’m at an antique store!!

halleys-comet-1986In the late 1700s and early 1800s one might say that the astronomical community was gripped by “comet fever”. Many astronomers, including Charles Messier spent many nights at their telescopes hunting for comets. Messier himself discovered over ten comets, as well as many star clusters, nebulae, and galaxies (Later known as the Messier Objects) that he cataloged as “non comets.” “Comet Fever” also took the public by storm, leading to many interesting pieces of artwork.

My particular favorite are the Halley’s Comet pins. Inspired by the unique shape of a comet in the sky, these pins are often simple in design. They are often a horizontal brooch style pin usually about an inch and a half long, with a gem placed at one end to represent the comet itself, and a thin bar to represent the tail. To the untrained eye, the pins appear asymmetrical and somewhat strange. These pins were quite the trend in the mid 1800s to the early 1900s. They range in intricacy, type of metal, as well as type of gemstone.

Earlier pins tended to have highly ornate metal working in the “tail segment”.

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The style evolved into a more streamlined, modern look in the early 1900s.

The comet pin underwent a radical change in the mid to late 1900s, pins became large and more compex.

Below is one of the pins from the LASM collection.

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The pins in our collection all date back to around 1835. Note the detail in the metal tail.

The exhibition “Vagabonds of the Solar System: Comets Past and Present” opens at LASM on November 19th! Visit the museum to view our collection of comet pins and vintage comet memorabilia, and to learn the historical and scientific significance of comets.

Juno Update

NASA is back up and running, and we’ve got some pictures back from Juno! The spacecraft bound for Jupiter, made a close flyby around Earth two weeks ago to get the gravitational assist it needed to reach the outer solar system. While passing Earth, Juno snapped a picture of our home planet. It also tested some instruments to make sure they were ready to go upon arrival at Jupiter.junoearth

Click here for status update of the Juno mission.

The Full Dome Saga Pt 3: Creating the Dome Master

Welcome back to The Full Dome Saga, the story of full dome production. Check out parts 1 and 2

So what is a “dome master”? Most planetarians like to consider themselves masters of the dome, but that’s not what we’re talking about here.

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This is a dome master!

Frames for full dome movies are square with a circular image inscribed within it, this is called a dome master. When looking at a dome master on a flat screen it looks like a distorted spherical image, but when projected upward onto the dome the image produces an accurate immersive effect for the viewer.

superfisheyeHow do you make a dome master? Unfortunately it isn’t really as simple as taking footage or images intended for a normal flat screen and running them through some software to make them immersive. You need to capture the footage differently using special camera lenses. The super fisheye lens captures the 180 degree perspective necessary to get enough picture to fill the dome.

Many inexpensive cameras can capture high resolution still images, like Bryce Canyon image above. However, those megapixels aren’t put to use in video capture mode. The maximum video resolution for most digital cameras and DSLRs is a 1920 x 1080 rectangle (perfect for your HD TV at home!). Remembering back to previous articles, the fisheye lens produces a spherical image inside the camera’s sensor frame. So when capturing a video with a DSLR and fisheye lens you get a maximum of a 1,000 x 1,000 pixel dome master video. Which isn’t nearly enough!

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Red Epic pixels are expensive, look at all the wasted pixels on either side! Luckily this was shot with a much less expensive Canon 7D!

So, let’s put one a fisheye on a Red Epic and start filming! Again, hold your horses… The frame captured by a 4k movie camera is not a square image either, its approximately 4,000 pixels wide by 2,000 pixels tall (just what you need for a regular movie theater). Slap a fisheye lens on there and you get a large black rectangle, with circle in the middle of it. Planetarium producers only care about the height of the frame, that is the maximum for how big our dome master will be. So a 4k movie camera that costs $100,000+  will only yield a 2k dome master, and the resolution to either side is thrown away. Bummer!

This has been the main reason that full dome movies up until now have been mainly composed of computer animation. That and of course we don’t have a lot of live footage of outer space. In recent years full dome movies have moved beyond just astronomy topics. There are biology shows, chemistry shows, history shows, and entertainment shows featuring roller coasters in outer space. Computer animation has been the solution for planetarium producers for how to get that true 4k by 4k dome master at whatever frame rate they want.

When producing CGI content, an animator essentially creates a virtual movie set. With virtual objects, virtual lights, even a virtual camera. The animator assigns textures to the objects, and makes them move. When the scene is finished, the animator picks the resolution that they want, then the scene is rendered. This means, that the computer creates each individual frame of the animation. One frame at a time, the computer calculates how the scene should look based on the lighting and texturing of the scene as seen from the point of view of the virtual camera. Those frames are then assembled into a movie.

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An unrendered scene. Virtual Dome Camera is circled. “+” signs represent steam and ice particles that will be generated during rendering.

When producing for the dome, the animator uses a virtual camera that has a virtual super fisheye lens on it. In fact this virtual camera can capture beyond the 180 degree field of view, difficult to do with a real camera. Many full dome animators use a field of view of 200 degrees or more. This captures more of the scene, giving the viewer an even more realistic experience. At render time, the animator chooses an output resolution of 4,000 x 4,000 and renders out dome master frames, that will later be assembled into a movie.

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You see more of the scene with a wider field of view! The experience becomes that much more immersive for the viewer.

So is the sky the limit here? Not really. Come back next time to learn about how rendering actually works, and the time required to produce a 4k animation.

Juno Spacecraft to Pass Earth October 9th

The Juno spacecraft is using Earth for a gravity assist this Wednesday, October 9th! In case you aren’t familiar with Juno, it is a NASA spacecraft built to study Jupiter. I feel a special connection with Juno, because I watched it launch from Cape Canaveral aboard an Atlas V rocket on August 5, 2011.*(For more on that see the end of the article).juno

Juno is scheduled to reach Jupiter in 2016. Fun fact: Juno is the first spacecraft sent to the outer Solar System that uses solar power as its primary energy source. Juno has three huge solar panels, each nearly the size of a tractor trailer. They folded up neatly while inside the Atlas V for launch, then opened outward once in space. These panels will face the Sun, collecting energy for the duration of the voyage. Juno weighs about 8,000 pounds and is named for the Roman goddess Juno, wife of Jupiter (known as Zeus in Greek Mythology).

To get to Jupiter, Juno will perform a gravity assist using Earth. Essentially, it will use Earth’s gravity to slingshot itself out into space. The gravity assist will give Juno an extra boost of speed then it will coast the rest of the way to Jupiter. Juno is a very large spacecraft, and it will most likely be possible to view it as it makes its flyby. Unfortunately for viewers in the United States, Juno will not be visible. Observers in parts of Africa and Asia will be on the lookout. Don’t worry, you can tune in on Slooh.com for a live news feed of Juno‘s flyby. Click here for an observational chart of how to spot Juno around the world.

So what is Juno going to do once it gets to Jupiter? Juno will orbit Jupiter thirty-three times between July of 2016 and October of 2017.  It will travel in highly elongated orbits that will be slightly shifted so that after all thirty-three passes, Juno will have passed over the entire surface of Jupiter. The purpose of this elongated orbit is that it allows the craft to skim very close to Jupiter, but then takes it away again, therefore minimizing its exposure to the strong radiation coming from Jupiter. Juno will map Jupiter’s gravitational and magnetic fields, helping us better understand the structure of the planet.  It will study Jupiter’s aurorae at its poles. Juno will also measure its chemical composition more closely, including its water content. All of this information about our Solar System’s oldest planet will help scientists gain a better understanding of how Jupiter formed, which will in turn better our understanding of the formation of our entire Solar System.

Will Juno stay out there forever? Juno has a very specifically timed mission, and once it completes its work, Juno will crash into Jupiter’s atmosphere. At the end of its mission, Jupiter’s radiation will have destroyed most of the spacecraft’s instruments despite its thick shielding. The main reason for the crash down is to prevent Juno from landing accidentally on one of Jupiter’s moons. An accidental landing of an Earth spacecraft could contaminate these environments, which would complicate future study.

One last fun fact: Lego figures of Galileo as well as the Roman gods Jupiter and Juno are aboard the spacecraft.junolegos

*Below is the full dome footage that I captured of the Juno launch. We were as close as civilians could get (we were bussed in). The actual blastoff happens around two minutes in. If you watch the whole thing you can hear mission control doing preflight checks and the countdown. Also, there was a dad with his two kids who was VERY excited about the whole affair, and provides some humorous commentary throughout the video. We were far enough away that we experienced the launch in stages. First we saw the light of ignition, then a few seconds later we heard the rumble of the engines, then a few seconds later we felt the heat blast. Yes, in 95 degree Florida heat from over a mile away we still felt the heat blast from the rocket. It was truly an awesome experience.

“Han Solo” On Mercury

Han Solo on Mercury 1

The MESSENGER spacecraft has been orbiting Mercury for some time. A few weeks ago it snapped this image (left) of the northern region of the Caloris basin. A strange, elevated land formation captured at just the right angle bears a striking resemblance to the smuggler who “can make the Kessel Run in less than twelve parsecs” or “is a stuck-up scruffy-looking nerf-hearder” (depending on who you ask).

Scientists think that this part of Mercury’s surface may have been part of the original terrain from before the basin was formed (most likely by a large impact event).

Seeing a familiar shape in random landforms is all in good fun, and examples of this have hit headlines other times before (think the “Face on Mars”). The official term for it is pareidolia.

Check out a similar human tendancy known as apophenia in last week’s article relating Pink Floyd’s Dark Side of the Moon with “The Wizard of Oz”.

 

 

Happy Autumnal Equinox, balance an egg!

I decided to take a break this week from Full Dome Saga to observe the upcoming autumnal equinox, which occurs on Sunday, September 22. I was having a conversation the other day about the first day of fall, and the age-old subject of balancing an egg came up in the discussion.  Can you balance an egg on the equinox????

First, let’s take a look at the equinox itself. For a refresher on the reasons for the seasons, click here .seasons

Last time I wrote a seasonal article, our Earth’s axis was tilting towards the Sun on the summer solstice. Now, the Earth has traveled along another quarter of its orbit. The Earth is still tilted, but the axis is leaning neither towards nor away from the Sun. Earth-lighting-equinox_EN This happens twice per year (once during fall and once during spring).  On the equinox, the day and night are about the same length. The name equinox is derived from the Latin words aequus, meaning “equal”, and nox, meaning “night”. If you are standing at the equator, the Sun will appear directly overhead at noon; both poles receive equal sunlight. For us up here in the Northern Hemisphere we are observing the start of fall. Remember, however, that down in the Southern Hemisphere they will be celebrating the vernal equinox as they are moving into springtime.

So where does the egg fit into all of this? Some say the idea of balancing the egg was started by the ancient Chinese. Balancing an egg on the equinox symbolized equality and the balance of light and darkness.  You can do this yourself at home. It is a challenge to balance an egg, due to its shape and its viscous interior (not to mention the position of the yoke throwing it off balance).
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Balancing the egg on the equinox became a phenomenon mainly because the idea was passed from person to person. People thought that the equinox was a special day on which you can balance an egg. Perhaps this gave people the extra motivation to really try and get that egg to stand up. Successful egg balancers felt validated by their triumphs, which furthered the notion that this could only be accomplished on the equinox. This most likely led to the big misconception that the cause is a special balance between the gravitational pull from the Sun and the gravitational pull of the Earth during the equinox. This is not the case. So what makes the egg stand?

The answer is: our efforts! Try it yourself. The egg can balance upright on any day of the year. It takes time, concentration, and steady hands, but it can be done. Perhaps that was the original intent of the egg balancing; it’s a way to meditate and ponder on the first day of the new season. So go forth, celebrate the coming of fall, and balance an egg!

The Full Dome Saga Part 2: Resolution and Frame Rate

Welcome back to the Full Dome Saga. For those of you just checking in, last week’s article can be found here Part 1.

So what is a 4k production? It’s a full dome movie that takes four Kyras to produce it, a 4K production…..

Jokes aside… 4k is short for 4,000 pixels.

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The movement here is not smooth.

Movies everywhere are made up of individual images called frames, played back at high speeds to simulate motion. The higher the frame rate, the smoother the motion and the higher perception of realism. Low frame rates cause motion to appear jerky and the picture to flicker. Think back on early films from the 1930s and 1940s, or funny internet GIFs of today.

When we go to a movie theater and they advertise that they are a 4k cinema, what they really mean is that their movie is 4,000 pixels wide and 2,000 pixels tall (roughly) because movies are rectangular (your HD tv at home is 1920×1080 pixels). So each frame is approximately 4,000 pixels across and 2,000 pixels tall.

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Back away Smeagol, you look to realistic at this frame rate!!

Generally, movie theaters run at 24 frames per second.  Peter Jackson made headlines when he offered The Hobbit at 48 frames per second (gasp!). Many still argue that high frame rates for live action films on flat screens produce too much realism for the audience to enjoy. Personally I enjoyed they hyper realism of The Hobbit at 48 fps, but that’s just me.

Movies like The Hobbit push the envelope for current technology. Capturing live action at high resolutions and high frame rates (then double this for two cameras if you’re making a 3D movie), require sophisticated and expensive camera equipment. The Red Epic (used to film The Hobbit and other recent blockbusters) is advertised as a 4k camera. I am often asked, why don’t you planetarians use that to get 4k live action footage for your dome? Not so fast son….

Here in the planetarium things are a bit different. Rather than a rectangular screen in front of you, there is a hemispherical screen that surrounds you. The movie is in front of you, next to you, above you, and behind you. 4k in the planetarium world means each frame is 4,000 by 4,000 pixels (a square rather than a rectangle) twice the number of pixels per frame.

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“To Space and Back” produced by Sky Skan. This full dome movie is available in 8k, 60 frames per second, and 3D!

Many digital planetaria run full dome movies at 30 frames per second, but producers are beginning to push the envelope. If you thought The Hobbit at 48fps was crazy, some digital planetaria offer full dome movies at 60 fps. The high frame rate applied to CG graphics creates that extra degree of smoothness and realism in the motion of objects on the dome. Stay tuned, as we have been dabbling in this a bit ourselves here at LASM!

The planetarium dome is a larger surface that surrounds the audience, unlike a traditional movie screen. Therefore motion is amplified on a dome screen. For this reason planetarium shows are edited with longer cuts than traditional movies and TV content, camera movement is slower, and objects move slower. Movement that is fast and somewhat jerky on a flat screen will look even more so on a domed screen. High frame rate smoothes the motion, resulting in a more realistic experience.

Why are most full dome movies CGI you ask? Come back next week for The Full Dome Saga PT3 where we will investigate the ins and outs of Live Action vs CGI production for the dome…..

The Full Dome Saga Pt. 1: From Mechanical to Digital

The Full Dome Saga Part 1: From Mechanical to Digital

Hello Readers, you are about to embark on a journey through the world of planetarium technology and production. Every Friday for the next few weeks we will explore all things digital planetarium. The first part of the Full Dome Saga is a brief background on the  technological evolution from the traditional planetarium to the digital dome of today. In later posts we will compare production techniques and equipment used for Hollywood movies to that used for planetarium production, animation and rendering techniques, live action capture, and more.

When many people think planetarium, they imagine a dark, domed room with a strange machine in the center. They imagine a mystifying experience where a presenter takes them on a tour of the stars and constellations in our sky. In the last ten years, the digital revolution has taken the planetarium on an interesting journey (which is far from over). With advances in digital projection systems, software and computers, planetaria are transforming into immersive theaters. Using anywhere between one and thirty projectors, a bank of synchronized computers, and sophisticated software, planetaria are pushing the boundaries of possibility for both education and entertainment.

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These digital systems allow presenters to move beyond the traditional night sky star talk. In a digital planetarium you can watch a full dome movie, specially produced to cover the entire dome, providing a “you are there” experience unlike any other. Differing from traditional movie theaters, digital planetaria possess realtime astronomy visualization software. A presenter can simulate and navigate through actual astronomical data in real time, almost like a video game.  Full dome content is still largely CGI, with only small amounts of live action. Where are the IMAX type nature films designed for the immersive planetarium theater experience? They’re coming…. (I hope!)

Here at LASM the Irene W. Pennington Planetarium houses a 4k digital projection system made by a company called Sky Skan. Our image on the dome is created by two projectors (one at the front and the other at the back of the dome). There are four computers sending visual information to each projector, and one computer that stores the surround sound (see picture at left). All of the computers are controlled by a main master computer and a software called Digital Sky and SPICE. In order for everything to run seamlessly (no pun intended) all computers must run simultaneously with no lagging.

Why are there so many pieces? Projecting a 4k video at a normal frame rate requires multiple computers to share the job, each one takes a small piece of the video to send to the projector (allowing everything to run quickly and smoothly). Current projector technology makes it difficult and expensive to cover a large 60-foot dome with a high quality image using a single projector, so we use two. Other planetaria use four, six or more to accomplish this task.

What does 4k even mean anyway? And does frame rate matter? Return next week to learn about how projection and video in the planetarium compares to your HD TV…