Notes on Celestia
(The above look best in the Print Preview of the Opera web browser.)
- Warning: Do Not Print
- Controls for Celestia
- Number Pad (with Num Lock turned on)
View and navigational
Motion (spaceflight)
Object labels Time
Other
Important commands for realism
Informational commands
Multiview
Mouse functions
- The farthest objects visible with the naked eye
- How to make any location on Earth be labeled in Celestia
- To go to any location on Earth
- How to figure out what tropical, not sidereal, zodiac sign anything is in while viewing the sky from the Earth's surface
- UT = Universal Time = GMT = Greenwich Mean Time
- Links to locations within Celestia
- Celestia web links
Warning: Do Not Print
I wouldn't recommend printing this exact page - since it's formatted for display on screen, not printing.
Firstly, there's clutter in the form of the navigational header, footer, and the ads. And, judging by the Print Preview in Internet Explorer, the tables might not come out in a very organized way. And plus, there's a background image, the text colors are not really suitable for printing, and the black background for the table headers might waste lots of ink.
You might have better luck with the possibly printable version, which at least looks decent in the Print Preview in the Opera web browser, but not Internet Explorer.
There's also a possibly printable version which has only the tables detailing the controls, Controls for Celestia. It also definitely looks best in the Print Preview of the Opera web browser.
Controls for Celestia
The farthest objects visible with the naked eye
According to http://www.wonderquest.com/naked-eye.htm, "The farthest star that we can see under the best of conditions is probably about 4,075 light years away."
So, for realism, you can go to the Render menu, select View Options, and use the little sliding bar underneath "Filter Stars" to filter stars by their distance in light years.
According to http://celestia.teyssier.org/doc/opt_stars_visible.html:
"On the surface of Earth, our view generally includes stars of an apparent magnitude of +6.5 or less (the lower the number, the brighter the star). Setting this option to Magnitude 6.5 - 7.5 results is a realistic sky as seen from Earth on a clear night, with only about 3,000 stars visible."
According to http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=45851:
"The remotest heavenly body visible with the naked eye is the Great Galaxy in the constellation of Andromeda. A silver smudge in the sky gives the Andromeda Galaxy away - at a mind-boggling 2,200,000 light years from Earth, anyone can spot it! One of the closest galaxies to our own, the light we see is the result of 200,000,000,000 stars shining together. The spiral galaxy is said to have been discovered by German astronomer, Simon Marius, around 1611."
How to make any location on Earth be labeled in Celestia
You can have any location on Earth be labeled in Celestia by opening the file world-capitals.ssc in the Data folder using a text editor, and adding something like the following:
Location "Hubbard, OH" "Sol/Earth"
{
LongLat [ -80.5666 41.1 0 ]
Importance 1000
Type "City"
}
To get the .5666 in the -80.5666, you have to divide the 34 (in 80:34W) by 60. To get the .1 in the 41.1, you have to divide 6 (in 41:06N) by 60.
To go to any location on Earth
First, I suggest sync-orbiting the earth by selecting it (either by clicking on it or pressing Return or Enter on the keyboard and typing its name), and then pressing Y on the keyboard.
You also might want to toggle cloud-rendering by pressing I.
Lastly, you can get rid of a pesky blue sky by turning off atmosphere rendering, by going to the Render menu, selecting View Options and unchecking Atmosphere.
To go to a particular latitude or longitude on Earth:
- Go to the Navigation menu and select Goto Object.
- In the box that comes up, at Object:, type in Earth.
- Put in the latitude and longitude in the same format used in the preceding example.
(For instance, 41.1 latitude and -80.5666 longtitude rather than 80:34W 41:06N). - And, pick a distance like .02 km. This will be your altitude - about 20 meters above the surface. If you get much closer than this, weird things may start happening with the graphics.
How to figure out what tropical, not sidereal, zodiac sign anything is in while viewing the sky from the Earth's surface
Those of you out there who are interested in astrology can easily figure out what zodiac sign various things are in by going to a location on the earth's surface (as described above), then pressing ; on the keyboard to show an "earth-based equatorial coordinate sphere".
Look around the sky until you find the center of the wheel. Looks kind of familiar, doesn't it. (Actually, though, in case it's too hard to find, here's a Celestia link directly to an example of what I mean - at the date and location of my birth).
The 12 pie slices you see are pretty much equivalent to the 12 tropical zodiac signs. But how do you tell which one is which? Well - this probably won't work for dates in the distant past or future, due to the precession of the equinoxes.
But, in dates close to the present, if you turn on constellation labels by pressing = on the keyboard, Ursa Minor will be found in the pie-slice which (I think?) contains things in Scorpio. The next pie slice counter-clockwise after that (I think?) contains things in Libra, and so on.
Of course, at any particular time, generally the only things you'll see in the sky are the things that are in the astrological houses 7 through (and including) 12, since those are the only houses visible above the horizon. (Though you might able to see some things that are at the beginning of astrological house 1 and the end of astrological house 6, very close to the horizon).
UT = Universal Time = GMT = Greenwich Mean Time
If it's 12:00 PM Eastern Standard Time, GMT or UT is 5 hours ahead, so it's 17:00 GMT or UT.
If it's 12:00 PM Eastern Daylight Time, GMT or UT is 4 hours ahead, so it's 16:00 GMT or UT.
For other time zone information, look here: http://www.computerhope.com/jargon/t/time.htm
Links to locations within Celestia
- A nice view from "above" the solar system at the time of my birth
- The sky at the time and place of my birth; viewing my Saturn/Jupiter/Asc conjunction.
Celestia web links
- Celestia Home
http://www.shatters.net/celestia/