The Taurids is a long-running minor meteor shower producing only about 5-10 meteors per hour. It is unusual in that it consists of two separate streams. The first is produced by dust grains left behind by Asteroid 2004 TG10. The second stream is produced by debris left behind by Comet 2P Encke. The shower runs annually from September 7 to December 10. It peaks this year on the the night of November 4. Unfortunately the glare from the full moon will block out all but the brightest meteors. If you are extremely patient, you may still be able to catch a few good ones. Best viewing will be just after midnight from a dark location far away from city lights. Meteors will radiate from the constellation Taurus, but can appear anywhere in the sky.
This upcoming April 25th will be Astronomy Day. It is an annual event in the United States that promotes interaction between the general public and the various astronomy based organizations, enthusiasts, groups, and professionals. Baton Rouge has several events planned to celebrate this day including the participation of the Louisiana Art & Science Museum and the Highland Road Park Observatory.
An exception from the federal government shutdown has been granted to NASA’s MAVEN mission “in order to protect U.S. property”. The property or properties we are talking about are on the planet Mars; the rovers Curiosity and Opportunity. If MAVEN’s launch window, which is only from November 18th through December 19th or 20th, is missed the next opportunity won’t come along until 2016. This delay would cause major problems since MAVEN’s communication equipment will take over the jobs that Mars Reconnaissance Orbiter and Odyssey have been doing and will allow us to continue to communicate with both rovers. Both MRO and Odyssey have passed their planned lifetimes. Preparation for the launch of NASA’s MAVEN mission has resumed and will continue on an emergency basis.
Besides being equipped to communicate, MAVEN will also probe the Martin upper atmosphere for clues to how the atmosphere has thinned and where its water has gone. MAVEN stands for Mars Atmosphere and Volatile Evolution mission.
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.
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.
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.
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 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.
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…
As the planetarium projectionist I get the pleasure of sitting behind the scenes and watching the variety of reactions people can have to what they experience under our dome. Being the person at the controls I can rotate the sky, fly you out to the furthest reaches of our universe, dazzle you with laser light, or make you tap your feet with our music and sound system. There is certainly a myriad of ways I can impress people while in the planetarium. It’s a very unique experience unlike what you would get in any other theater.
One of the things I see and hear from people after a show is that when they leave the theater they look around trying to figure out where everything is coming from. All they see is a dome above, the circular wall of the theater, and a place to sit.
Where is all the sound coming from and where are the speakers?
Where do the lasers come from?
How do they get the image on the dome?
And, how do they make the dome change colors like that?