Starry Night - a planetarium for your PC

Developed by Sienna Software (now known as Imaginova) in Toronto, Canada.

Calendar activities:

North Pole activities:

Christmas activities:

Events of Interest (viewed from Al-Basrah, Iraq)

Event 1: April 17, 6 BC

                                    ͦ Uranus

                                ͦ Venus
                            ͦ Saturn
                        ͦ Moon (waning crescent)
                    ͦ Jupiter
     ---------- ͦ Sun ------------------------------
            ͦ Mars
        ͦ Mercury

Event 2: April 24, 6 BC

Simulator Time Event
6BC-04-24 05:00 to
6BC-04-25 05:00
Venus (partially?) occults Saturn in the constellation of Pisces
step the time day-by-day Venus moves from Saturn toward Jupiter
6BC-05-08 05:00 Venus (partially?) occults Jupiter in the constellation of Aires
6BC-05-11 05:00 The Moon appears in the simulator's field of view and is moving toward Saturn
6BC-05-14 05:00 The Moon has jumped past Saturn and continues to move toward Jupiter
6BC-05-15 04:00 to
6BC-05-15 08:00
The Moon has occulted Jupiter before moon rise and Jupiter is never seen again that day because of sunlight
6BC-05-16 05:00 Jupiter is now visible and the moon has jumped past it and Venus
6BC-07-08 05:00 Mars, Mercury, and Venus are grouped in the constellation of Gemini
(this event probably has nothing to do with the above events but was included only because it looks cool)

Event 3: April 27, 7 BC

Simulator Time Event
7BC-04-25 05:00 Jupiter, Saturn, and the Moon are  grouped just to the right of Pisces (an astrological conjunction)
7BC-04-26 05:00 The moon has dropped away and now only Jupiter and Saturn are still grouped
step the time day-by-day Jupiter appears to move closer to Saturn as they both move together closer to Pisces
7BC-05-29 05:00 Jupiter and Saturn appear to touch in Pisces (astronomical conjunction #1)
step the time day-by-day Jupiter and Saturn separate slightly and Jupiter appears to pull Saturn into Pisces
7BC-06-19 05:00 to
7BC-06-19 05:00
The Moon has joined the two planets again in Pisces
7BC-07-17 05:00 The Moon has joined the two planets again in Pisces
7BC-08-13 05:00 The Moon has joined the two planets again in Pisces but this time occults Saturn
7BC-08-14 05:00 The planets start to move closer together
7BC-09-08 20:00 to
7BC-09-09 05:30
The Moon has joined the two planets again in Pisces and begins to move very close to Saturn. At 5:20 the two touch just as they set in the West.
7BC-09-11 19:00 Jupiter continues to approach Saturn
7BC-09-30 19:00 Jupiter appears to touch Saturn (an astronomical conjunction #2)
7BC-10-10 17:00 to
7BC-10-11  03:00
During the conjunction of Jupiter and Saturn, the indicator for Earth's shadow will be displayed with Jupiter dead center.
Click here to see why the Earth cannot throw a shadow all the way to Jupiter
7BC-10-17 19:00 to
7BC-10-31 19:00
Jupiter and Saturn appear to separate a small amount
7BC-11-01 19:00 to
7BC-11-14 19:00
Jupiter and Saturn maintain their distance from each other
7BC-11-15 19:00 to
7BC-11-28 19:00
Jupiter and Saturn begin to move closer to each other
7BC-11-29 19:00 Jupiter appears to touch Saturn (an astronomical conjunction #3); Saturn appears to touch the Moon
7BC-12-10 19:00 Jupiter and Saturn are now beginning to separate
6BC-02-16 19:00 Jupiter and Saturn are now quite far apart

2004-12-xx email from Imaginova

One of the nicest things about Starry Night is that it can serve as a bridge to people who aren't quite as interested in astronomy as I am. This holiday season I decided that I wanted to show my "normal" friends and family what Starry Night could tell them about Christmas.

The Christmas Star, or "Star of Bethlehem", reportedly acted as a beacon for the Three Wise Men to follow from the Middle East to Bethlehem and Jesus' birth.

I've heard many explanations over the years: a comet, a supernova, meteors, a supernatural event. Now, I have access to the perfect simulation tool.

Here's what I did...

From what I could learn, most astronomers and Biblical scholars believe that the appearance of the Star of Bethlehem most likely occurred sometime between the years 7 and 2 BC. Was there anything unusual in the sky that might have caught the attention of the wise men?

Just so happened that a very close conjunction of Venus and Jupiter would have been visible in the eastern dawn sky of the Middle East from about 3:45 to 5:20 a.m. on August 12, 3 BC. The two planets came together in the constellation of Leo. To the early Israelites, Leo was a constellation of great astrological significance and considered a sacred part of the sky. The planets came so close together that most people saw it as one object, a very striking sight.

With this information, I used Starry Night to go back in time and recreate the August 12, 3 B.C. event. You can do it too...

  1. Change your Viewing Location to Bethlehem, West Bank.
  2. Set the date in Starry Night to August 12, 3 B.C. (not A.D.)
  3. Set the time to 4:30 a.m.
  4. Turn on the constellation stick figures (press K on your keyboard if using version 4 or 5)
  5. Face East (press E on your keyboard)
  6. You should see a bright star just above the horizon and slightly to the left in the constellation of Leo.
  7. Turn on the planet labels. You should now see that the bright star is not a star at all but in fact two planets - Venus and Jupiter.
  8. Right-click (Ctrl-click on the Mac) on the bright star and select Centre from the popup menu that comes up.
  9. Zoom in using the zoom buttons. Note how close the two planets were!
  10. If you want to save this view as an .SNF file then select Save from the File menu.

Two notes...

Finally, for more info on the Star of Bethlehem, check out Star of Bethlehem: Going back in time to explore its origins from the fine folks at Space.com.

Seth Meyers
VP of Consumer Products and Experiences
Imaginova

Explanation of: Why Earth Can't Cast a Shadow on Jupiter or Saturn

While playing with the Starry Night v5 simulator during the above experiments, you will occasionally see an eclipse indicator activate over Jupiter. This indicator is only valid for the Earth's moon as the following document (taken from internet news group "alt.astronomy") describes.

From: "Greg Neill" <gneillREM@OVE.THIS.netcom.ca>
Subject: Re: "Star of Bethlehem" additional info
Date: 2004-12-27 12:04

...the Sun is not a point source; if you imagine drawing lines tangent to the Sun and Earth, they will converge (more or less) at a point somewhere out past the Earth. Beyond that, an eclipse is at best annular. Much beyond the focal point, diffraction will conspire to make the eclipse a complete non-event; an observer stationed on the body expecting to be immersed in the Earth's shadow will merely see the Earth silhouetted against the Sun's disk, and won't see much in the way of darkening.

Now, the Moon is a pretty close-by object astronomically speaking, and yet it suffers annular eclipses of the Sun by the Earth, and when it does, it does not "wink out" but merely dims. Saturn and Jupiter are *much* further out than this focal point.

Let's do a few calculations just for fun. Start with some basic data:

AU = 1.496x10^8 km Astronomical Unit
Rsun = 6.9599x10^5 km Sun's radius
Re = 6371 km Earth's radius
de = 1.00 AU Earth's distance from Sun
djup = 5.20 AU Jupiter's distance from Sun
dsat = 9.54 AU Saturn's distance from Sun

First let's see where the "focal point" is in relation to the Earth. Letting "df" be the distance from the Sun to the focal point, we can set up the ratios:

Rsun/df = Re/(df - de)

so that:

df = (Rsun x de)/(Rsun - Re)

df = 1.009 AU

Which is pretty darn close to the Earth's distance from the Sun. Note that the Moon is about 0.0026 AU from the Earth, which is inside this focal distance.

At the distance of Jupiter, the Sun subtends an angle of:

Qj = 2 x asin(Rsun/djup) = 0.102 degrees

While the Earth subtends an angle of:

Qe = 2 x asin(Re/(djup - de)) = 0.0012 degrees

So the Sun's disk appears about 88 times larger than the Earth's at the distance of Jupiter.

A similar calculation for Saturn shows that the Sun's disk appears to be about 100 times the size of the Earth's. So there cannot be a naked-eye perceptible eclipse of either planet.

Adding "Sirius Radio Satellite" Definitions

Satellite Web Links:

Item Links
 Master TLE Index http://celestrak.com/NORAD/elements/master.asp
 TLE file containing Sirius + XM definitions http://celestrak.com/NORAD/elements/other-comm.txt
 TLE web site http://www.space-track.org

 Starting the Starry Night Pro application software causes one of the following two files to be loaded...

C:\Program Files\Starry Night Pro 5\Sky Data\Satellites.txt
C:\Program Files\Starry Night Pro 6\Sky Data\Satellites.txt
    or
C:\Program Files\Starry Night Pro Plus 5\Sky Data\Satellites.txt
C:\Program Files\Starry Night Pro Plus 6\Sky Data\Satellites.txt

...which contain Satellite definitions in TLE (Two Line Element) format. Right-clicking on the third link above will download a fresh copy of a TLE file with Sirius-Radio + XM definitions. Use an editor to add these definitions to the top of file "Satellites.txt" then restart Starry Night. Note that due to satellite orbit decay, these files should be updated monthly.

Click here to visit my Sirius Satellite Radio page

Visiting Lunar Sites

  • in Starry Night Pro Plus 6.0.1, all Apollo sites contain the correct mission photos (very cool)
    • Apollo 14 photo is similar to this one (but the MET can't yet be seen)
      • you cannot see the Surveyor 3 site from the Apollo 12 location which is only 180m (590f) away
    • Apollo 17 photo is similar to this one (but no LM is visible so this must be an EVA photo)

Not-So-Quick Fix

Moving "Starry Night Pro Plus 6" to Windows-Vista

Astronomy Reference Links

Note:this information is NOT required to operate or enjoy "Starry Night"


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Neil Rieck
Kitchener - Waterloo - Cambridge, Ontario, Canada.