Yesterday saw the first public beta release of Microsoft's WorldWide Telescope, the skyward companion to Microsoft Virtual Earth. After looking at Google's equivalent offering—Google Sky—a few months back, I spent much of last night putting WorldWide Telescope (WWT) through its paces. I can say that, without equivocation, WWT is incredibly impressive and in my opinion outdoes Google Sky in almost every category. (It did not, however, make me cry.)
Before I even downloaded the program, I was a bit amazed at the system requirements on the download page. The minimum stated requirements are an Intel Core 2 Duo chip running at 2GHz, 1GB of RAM with 2GB recommended, all on a system using Vista. Microsoft also recommends up to 10GB of disk space for optimal offline performance. I was pleased to find that my "meager" two-year old laptop powered by a 1.8GHz Pentium M with 1GB of RAM worked just fine, however. Earlier in the day, there were install instructions for Mac users which basically told them to install Vista; however, those seem to have been removed.
When I fired up WWT for the first time, I was greeted with an undistorted view of the night sky you would see if you looked up—save for the stick drawings of the constellations. This is in contrast to Google Sky, which uses some form of Mercator projection which distorts space and images at high or low declinations. WWT shows the universe not as though you are looking at a map, but as if you are sitting at the center of a hollow sphere, looking outward toward the edges.
While very convenient, this doesn't really represent what you would see if you looked up into the night sky—the Earth being in the way and all. To remedy this, the "View" drop down menu has the option to see what would be visible in the night sky from over 550 pre-programmed cities around the world. In addition to being able to select your physical location, you are free to pick your temporal location as well.
To help you find your way around the night sky there are some directional tools provided. In addition to displaying stick figures for each constellation, the right ascension (RA) and declination (dec) are shown in the lower right corner. For those who don't have a good sense of where an (RA, dec) pair is looking, a small sphere with a rectangular projection of the area of space you are looking at is available in the lower right as well. Moving around is simple and relies on the familiar click and drag interface. Zooming is controlled by the scroll wheel, and even on my "slow" laptop zooming and scrolling motions were smooth.
Where to go, what to see
Along with the stick figures for each constellation, the default view contains a simple reticle that is at the center of the screen. When the reticle is near a constellation, it will highlight an area of space around the constellation. The bottom of the screen will then fill with all the various things to see in the neighborhood of that constellation.
For example, in the neighborhood of Ursa Minor, there are 103 different objects that are clickable in WWT. A click on any of them in this bottom bar will zoom in and highlight the object, be it a galaxy, star, or other cosmic phenomenon. A glance at Pisces will allow one to take a detailed look at Uranus, Neptune, or the ring of dark matter in ZwCl0024+1652. If you aren't sure where to look for your favorite celestial object, a search option—with an extensive database—is provided to help you find it.
In a fashion similar to Google Sky, the detailed images are simply high resolution shots taken from various sources pasted over a lower resolution image of the background star field. One difference is the planetary bodies in our solar system. Each of these that I looked at was viewable as though viewing from orbit, and high resolution images of the surface are pieced together. Given this viewing mode, one can examine Jupiter's moon Io in a fashion similar to Earth.
If you don't want to do a free-form exploration of the universe, the top tool bar has the option to "Explore," which lists a host of collections of interesting things to see around the universe. These are similar to what was available in Google Sky a few months ago. One can pick from planets and moons in the solar system, Hubble images, Chandra images, Spitzer images, full sky surveys, or even a collection of named objects.
Screenshot of Microsoft WorldWide Telescope
While the default view is the night sky in the visible spectrum, WWT, like Google Sky, has the option to view the sky in non-visible spectrums. When viewing Chandra images, one easily sees what is visible in the X-ray spectrum; likewise, it's easy to spot what is hidden in the infrared when viewing through the lens of the Spitzer Space Telescope. However, instead of using a single data source for viewing the sky in various non-visible spectrums, WWT has multiple data sources for radio, infrared, X-ray, optical, gamma, and even microwave. Each can be selected to see what the universe looks like in that spectral range. If you have a telescope with compatible hardware or software, then the WorldWide Telescope can control it for you.
When you want an explanation
Where WWT really stands out is in its tour feature. These are files that are downloaded from Microsoft's WWT repository that consist of, essentially, a guided tour or explanation of one phenomenon or celestial object. Under the "Guided Tours" option, there are options for learning how to use WWT, view and learn about various nebulae, cosmology, black holes, or a supernova, among other things.
Each is akin to a Flash demo, where music and/or voiceovers by astronomers or Microsoft Research personnel accompany text and a tour around various parts of the universe. For instance, under the cosmology tours, there is one on dark matter. It is given by Mike Gladders, an astronomy professor at the University of Chicago. The tour highlights examples of extreme gravitational lensing that was captured by Hubble and visibly shows a number of galaxies distorted by a large amount of mass between us and the galaxies causing the distortion.
When first installed, there are 20 or 30 distinct tours available. However, the WWT allows users to create their own tours of the universe and share them with others. In fact, under the "Learning WWT" section is a section that illustrates how to create a tour not only across space but across time, demonstrating how to make a tour of the solar eclipse that will occur this August.
When I covered Google Sky, I called it "a guided tour at the local science museum." If I were to follow that analogy, WorldWide Telescope would be more akin to a tour of the Hayden Planetarium by Dr. deGrasse Tyson. The greatly expanded catalog of objects to look at, along with the guided tours, makes the WorldWide Telescope much more along the lines of what I was looking for in a Google Earth/Virtual Earth equivalent of the entire universe. Kudos to Microsoft Research for a compelling product.