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NVIDIA and the Celestia Program:
A Window into the Universe

image1.jpg “The Celestia program has broad appeal—from second graders all the way up to NASA scientists and engineers. By driving high-performance imagery from high-end servers onto commodity hardware, NVIDIA also brings this capability into every classroom and home. Celestia is a fantastic programming achievement—it gives everyone a window into our universe.” Alan Federman, senior engineer, Raytheon Technical Services Co., LLC, NASA Ames Research Center.

Image: High-resolution picture of Mars viewed using Celestia.

The Really Big Picture
Combine graphics programming skills with a love of science—astronomy and space exploration, in particular—and you get powerful new 3D visualization software that has scientific and academic communities changing the way they look at our universe. Written by Chris Laurel before he came to NVIDIA, the Celestia program runs on any PC, Linux system, or Macintosh computer, and is optimized to deliver stunning image quality with NVIDIA Quadro® and NVIDIA GeForce™ graphics solutions.

Celestia is an open-source astronomy program that displays high-resolution images like the above picture of Mars. Celestia displays these images by taking advantage of NVIDIA accelerations for high-resolution textures and bump mapping. Bump mapping is especially evident when you look at the clear representations of the large mountains near the edge of the sunlit hemisphere of Mars. The largest of the mountains is Olympus Mons—at three times the height of Mt. Everest, it’s the largest volcano in the solar system.

Anyone can obtain Celestia, free of charge, from the NVIDIA Web site. Celestia accesses star and galaxy catalogs and NASA image libraries, and lets you virtually “fly through” the universe.

A New Perspective
Maybe Chris should have been an astronaut. He’s always had a love of astronomy and a fascination with exploring the universe. Luckily for the scientific community, he pursued a career as a software developer, specifically in the area of 3D graphics at NVIDIA.

Background: Chris Laurel decided to put his 3D graphics programming skills to the test and create a new tool for visualizing the planets, spacecraft, stars, and galaxies in our universe.

Challenge: The Celestia program was written to be platform-independent. SGI OpenGL® functionality provided basic capabilities for building the visualization solution, but Chris wanted to maximize visual clarity and give users the best possible views of the existing data. Reliability also became a challenge, as Chris discovered that many OpenGL software drivers were unstable and buggy.

Solution: When combined with NVIDIA graphics platforms, the Celestia program delivers the best image quality to scientists, students, and anyone visually exploring space. Celestia takes full advantage of NVIDIA’s hardware acceleration, producing the best bump mapping, shadows, and atmospheric rendering when it’s run on NVIDIA Quadro and GeForce products.

Benefits: The efficient software implementation and high-quality, reliable NVIDIA drivers provide a solid and stable platform for Celestia. Stunning image quality ensures that the next generation of space explorers is captivated and inspired by using Celestia.
The challenge of writing a 3D graphics application appealed to Chris. He wanted to create something new and intellectually interesting, and something that would take advantage of the power of the leading NVIDIA Quadro graphics solutions. His interest in astronomy provided a perfect direction, especially when he noticed that the only available space visualization programs—predominantly planetarium software—were restricted to 2D and only presented a view of the sky from Earth’s perspective.

Today, the results of Chris’ work are receiving praise from NASA, educators, and students—people who have used and contributed to Chris’ Celestia program for taking a virtual trip to outer space. The program represents a major leap forward from previous planetarium software, whose limited 2D views from Earth could only be viewed by visiting a round-ceiling theater at a planetarium.

“The Celestia program has broad appeal—from second graders all the way up to NASA scientists and engineers,” explains Alan Federman, senior engineer at NASA Ames Research Center. “By driving high-performance imagery from high-end servers onto commodity hardware, NVIDIA also brings this capability into every classroom and home. Celestia is a fantastic programming achievement—it gives everyone a window into our universe.”

Part of NASA’s goal is to make mission data easily available to the public. NASA also looks for ways to bring excitement to the study of science. It actively supports teachers and works with them to develop techniques and tools to engage students. Federman says, “An important part of our mission at NASA is to inspire the next generation of explorers. Towards this goal, we want to give teachers tools that inspire kids to successfully apply themselves to STEM—science, technology, engineering, and math. Celestia is an invaluable tool for exciting and educating young people in the United States and around the world.”

Celestia remains Chris’ passion, and he still works on the program during his free time. Other developers, including NASA, now contribute to the program, which has grown to approximately 100,000 lines of code. Federman summarizes, “Celestia is already a big hit with teachers and students, and we think tech centers and museums would also be perfect settings for Celestia. We have lots of ideas for how we can extend the use of Celestia at NASA. We can see down the road the ability to hand out 3D glasses for a real eye-popping experience. The Celestia program has the potential to really change things significantly and positively.”

Use Celestia to follow the path the Cassini spacecraft took to reach its orbit around Saturn on July 1, 2004.

Your Ticket to Outer Space

Chris Laurel’s Celestia program, already downloaded more than three million times, serves as a powerful portal to the increasing number of space and planetary knowledge bases. This powerful tool uses NVIDIA graphics power to let users visually explore enormous data sets, including catalogs of stars and galaxies and collections of image data gathered by interplanetary spacecraft. From desktop or mobile PCs, users have the flexibility to view information a variety of ways:

Adjust the time setting: Move out of the present and use Celestia to check out future events, such as viewing the last leg of the

spacecraft Cassini’s trip to Saturn! Anyone using Celestia can follow the path NASA’s spacecraft used to reach its orbit around Saturn on July 1, 2004. In January 2005, Cassini will deploy the Huygens probe to land on Saturn’s moon, Titan, and give us our first look at a surface speculated to have seas of liquid ethane.

You can also travel back to the time of the earliest documented astronomical events and, for example, view the solar eclipse mentioned in Shakespeare’s play, King Lear. (It’s thought that Shakespeare was referring to the solar eclipse of October 2, 1605, when London residents saw 90 percent of the sun blacked out by the moon.)

Dynamically pan through the data: Fly through space following the paths of previous, or currently deployed, spacecraft.

Inspect Earth or any of the other planets, the sun, distant galaxies, and other astronomical entities: Zoom in and view the surface of the planets, or view detailed 3D models of spacecraft launched from Earth

No other 3D visualization tool provides such a powerful way to view our universe, and the combination of a PC platform and NVIDIA graphics makes this stunning view accessible to the broadest possible audience. Teachers are using Celestia to get students excited about science, and scientists at NASA and other research organizations are taking advantage of Celestia to provide realistic access to their space data. Plus, the general public is using Celestia to view space, including the newest images of Mars sent back from the Mars Global Surveyor, currently in orbit around the Red Planet. Anyone can obtain the free Celestia program and source code from the NVIDIA Web site. The program was written to be open and flexible, and Chris hopes that it will facilitate other advancements in visualization solutions. “Today, NASA is among the organizations that enthusiastically support Celestia,” says Patrick Hogan, manager of the NASA Learning Technology Project.

Celestia lets you view the Global Surveyor spacecraft orbiting Mars, and 
examine high-detail imagery of the planets, stars, and other and solar systems.

The NVIDIA Booster

The Celestia program runs on a variety of platforms and is graphics-board independent. However, Chris explains, “Running Celestia with NVIDIA Quadro or GeForce graphics gives users the best image quality. NVIDIA vertex and pixel shaders are used to render bump-mapped planet surfaces, accurate shadows for eclipses, and realistic atmospheric effects.”

NVIDIA graphics solutions also offer large amounts of memory (up to 256MB) and bandwidth (up to 27.7GBps). Celestia takes advantage of this memory capacity and speed to create detailed textures and a better overall viewing experience.

When Chris started developing Celestia, he learned a great deal about desktop graphics solutions. He was particularly impressed with the reliability of NVIDIA solutions and the efficiency of NVIDIA driver software. Chris comments, “Other OpenGL drivers were just too buggy to deal with. With NVIDIA, I only had to deal with one driver for all the NVIDIA graphics boards, and the software was rock solid. At one point during my project, I did discover a bug in the NVIDIA driver. I contacted NVIDIA, and they had a fix for it within three days.”

Chris was so impressed with the superior performance of NVIDIA hardware and the reliability of the NVIDIA software that he interviewed for a position at NVIDIA. As he explains, “I wanted to work at the best company for 3D graphics. It was great to interact with NVIDIA when creating Celestia, and now I get to be involved in the development of the platforms that will support next-generation Celestia capabilities.”

Download Celestia (10MB .exe)

NVIDIA GPUs let Celestia implement realistic atmospheric haze effects.