Vedic astrology, as a system, is based on fixed signs of the zodiac, unlike the tropical (solar) zodiac, which is tied to the equinoxes. What does this mean? Well, I’m no astronomer, but my understanding of it is that the tropical zodiac was initially aligned so that the first sign, Aries, matched the vernal (spring) equinox, while the sidereal system kept those separate. The equinox and the first degree of Aries no longer align when observing the sidereal zodiac. This is due to the precession of the earth which results in a shift of one degree every 72 years, which may not sound like a big deal, but at present there’s a difference of 23 degrees between tropical and sidereal Aries. When you say ‘the Moon is in Aries’, it’s visible in the sign of Aries in the sidereal zodiac. Just as the equinoxes are pin points for the tropical zodiac, the fixed signs were originally the foundation of the sidereal system. They are both ‘right’, but in different ways… Or rather, should be used for different things.
I chose the vedic and/or sidereal system because that resonated well with me, someone else might think differently. If you have a western birth chart, the positions I mention might have to be adjusted accordngly, although in sometimes – as is the case for my partner who has the Sun in the sign of Gemini both ‘sidereally’ and ‘tropically’ – they may coincide if the degree span of 23° still happen to fall within the same sign, which is 30 degrees. However, the exact position is still necessary to get the right Nakshatra (lunar mansion) and Navamsa chart (relates to your partner) and so on… I hope this all made some sense! Also, this is my understanding of it, any errors are my own!
Cosmic greetings, RoseAnna