Images from EIT at 195 and 304 angstroms, MDI Magnetogram, and LASCO C3.
Virtual Moon Atlas
Carte Du Ciel
Stellarium
By Dave Grosvold
In the dark and gloomy days of winter, is there still a way to engage in observational astronomy? Did you know you can observe the Sun when it’s cloudy? Did you know you can observe the entire night sky in the daytime? What about observing the Moon when it’s not visible in the night sky? These are all possible with some help from your computer and the Internet.
Observing The Sun
The Solar and Heliospheric Observatory web site provides images of the Sun in many different forms. All of these images are taken every few minutes, so you can follow activity on the Sun in near-real time. Images from the Extreme ultraviolet Imaging Telescope (EIT) are taken in several different wavelengths of ultraviolet light (304, 171, 284, and 195 angstroms). These wavelengths correspond to different surface temperatures on the Sun, from 60,000 degrees Kelvin to over 2 million degrees Kelvin. The hotter the temperature, the higher in the solar atmosphere we see.
The Michelson Doppler Imager (MDI) captures data that provides us with a view of current sunspot activity, such as this magnetogram image. The Large Angle Spectrometric Coronagraph captures activity in the solar corona by blocking out the overwhelming light from the Sun itself so the delicate corona can be seen. This allows us to see streamers and radial bands in the corona that would otherwise be invisible. Visit SOHO Explore! to learn more about the Sun and how it works.
Virtual Moon Atlas
Want to observe the Moon? The Virtual Moon Atlas is a free software download available for Windows, Mac, and Linux PCs that allows you to view very high resolution photographs of the entire surface of the Moon. There are thousands of identifiable features and a huge amount of detailed information, including multiple scientific overlays, including rock types, presence of certain trace elements, altitudes, surface temperature, iron oxides, etc.
The program is available in over a dozen languages, with complete documentation, quick star guides, and a multitude of downloadable add-ons including textures and picture libraries. PocketLun, the Pocket PC version of VMA is even available for Windows Mobile devices. VMA is a professional-level program and will provide even the advanced the Lunar Observer with hours of observational study.
Charts and Planetariums
There are a number of free sky chart programs on the market. The most notable is Carte Du Ciel (literally “Sky Charts”,) by Patrick Chevalley, the author of Virtual Moon Atlas mentioned above. Carte Du Ciel (CDC) has as many databases available as many of the expensive commercial offerings, and charts can be printed to great detail - as deep as most, if not all, printed star atlases. Many amateur astronomers use CDC as their software tool of choice when it comes to controlling a telescope in conjunction with their astroimaging equipment.
There are also planetarium programs free for the download, such as Stellarium. Stellarium displays the night sky much as it would look to a naked-eye observer out under the stars. This includes such things as light pollution, fog, meteors, and the effects of the full moon and sun in the sky. Stellarium can be used as a basic charting program, but printing charts is not it's forte. It's much more at home displaying the night sky in a realistic way. Stellarium has a planetarium projection mode that can be used with an appropriate projector to display the entie night sky form horizon to horizon in a dome. See their web site for more information.
Both of these programs are great tools and would be welcome in any amateur astronomer’s kit.
WorldWide Telescope
On a cold gloomy night in January, though, the best way to view the heavens is with WorldWide Telescope. WWT is a free product from Microsoft Research, and is available in the form of a Web Client for Mac, or as a download for Windows, that basically turns your computer into a Virtual Telescope. WWT brings together images from some of the world’s largest ground and space-based telescopes in a way that allows you to explore the universe in a seamless virtual environment.
WWT view of Jupiter
The images are breathtaking, and WWT provides a large number of guided tours that allow you to travel on a exploratory journey along with various astronomers from famous observatories and universities. See how dust in the Milky Way condenses into stars and planets! Travel 2 billion years into the past and learn how gravitational lensing works!
So you can’t get outside and see the night sky? Observe anyway, using these fantastic tools and the Internet!
