Libra Rising

Now is a good time to get a feel for the difference in the sky between Libra and Aries - or at least take a first step toward understanding. 

I was out this morn at 5:40 looking for Mars rising in Libra.  I thought I saw it but was never completely sure the whole time I hung out studying the constellations. I was waiting for Venus to come up.  When it did, it was of course bright and unmistakable.  But the distance in the sky between the faint light of Mars and brilliant Venus was farther than I thought it should be.  From the chart I knew they were only 16 degrees apart.  That 16 degrees in the sky looked more like 25 to me.

It took a while for me to become certain I was 'seeing' the longer rising time of the sign Libra.  I hope I can get another chance to observe in the next couple of mornings, while Venus is not much more than 15 degrees ahead of Mars in the zodiac.  15 degrees is 1/2 a sign. 

I made charts to show the difference in time between Libra and Aries rising.  We can't directly observe Aries rising right now, but Stellarium gives a good visual approximation.  Here is a link to a quick video showing the way the ecliptic changes through the hours.  Planetarium software helps find your way around the starry bowl, but it is no substitute for the real deal.  You have to go outside and see in the big expanse just how dramatic the difference actually is.  Once you see the variation from one sign to the next you will know the zodiac signs are not about the constellations, but about the changing distance between the ecliptic and the celestial equator.

And then there's the math.  19 mins for a small Libra section to rise vs 11 mins for the same section of Aries to rise.  I put colored smudges over the local times at the top of each chart.

The 4 charts:
5:40am (green)   13d Libra 29m rising

5:59am (blue)   17d Libra 25m rising

5:07pm (red)   13d Aries 21m rising

5:18pm (redder)  17d Aries 36m rising

AC is an abbreviation for ascendent.  It tells which degree of the zodiac was coming up at the the given time and location.  It took 19 mins for 4 degrees of Libra to rise and tonight, even though we can't see for that daggone Sun, it will take 11mins for 4 degrees of Aries to rise.

So if you get a good look at Venus and Mars while they are rising in Libra, there are a good two weeks left, you can compare that to a planet or two rising in Aries when the next opportunity comes along.  Starting at about 5:40 or 6:00am look east, where you see the Sun come up in the mornings, for the faint red light. Then pay attention to how far it rises until bright Venus comes up around 6:20 am.  The distance between them is what 16 or 17 degrees looks like in the sign Libra.

Happy sky watching!