With the technology on the verge of taking us to Mars in just a matter of decades, there is a distinct possibility that there can be children born on another planet. A equal possibility is a moon base where human being could settle in near future. This will blow all astrology out of the window as far as horoscopes and birth charts are concerned.
The way to construct the horoscope would not change at all. If we move from Earth to Moon or Mars, the nakshatras and others signs in the zodiac will not change much since the distance from Earth to these planets is much much less than compared to the distance to the stars in the Zodiac.
The equations to place planets in zodiac in the background of signs and nakshatras will not change. Instead of geocentric equations, these will be lunacentric or marscentric equations. This astronomy problem is already sorted out. Precession of equinoxes, i.e. Ayanamsha correction also does not change much. These problems will arise only if we were to move few hundred of light years, or to another galaxy through a wormhole, for example near Gargantua!
Lets me put some thoughts on how these horoscopes will be interpreted and what the challenges look like.
For a horoscope generated for a person born on Moon, naturally, moon will be missing in the horoscope. A signifactor of mind, emotions, mother will be missed. Solar eclipses will be more important than geo-eclipses. Rotation of Moon is pretty slow and the “hora” concept will change. Cancer will be lord-less.
This is an easy problem to solve. Earth has to fit in and will fit in as lord of Cancer. After all, we call it Mother Earth. The more complications will come when we consider Sun in a luna-centric orbit. If I am not wrong, in the reference of Moon, Sun will go retrograde once in a while and that effect will need to be understood. As of now, Sun doesn’t go retrograde any time in the horoscope, but for a Moon based chart, it will indeed. Rahu and Ketu are also Earth centric and the equations will have to be modified.
For a horoscope for Mars birth, there cannot be any Mars in the chart. Hence, who will be the lord of Aries and Scorpio? What will be the source of war and all the aggression? Pluto can be borrowed to be the lord of Scorpio, but that’s about it. Pluto cannot fill in for Mars as the lord of Aries. Where will the definition of Manglik Dosha go and what will be the new definition of Rahu and Ketu? Mars has two moons – Phobos and Deimos. They were discovered in 1877 and are named after the characters Phobos (panic/fear) and Deimos (terror/dread) who, in Greek mythology, accompanied their father Ares, god of war, into battle. They will need to be factored in.
For the sign of Cancer, Earth’s Moon cannot be used. Earth & Moon will pretty much show up together as a single entity as the distance from Earth to Mars is far greater than the distance from Earth to Moon. The combined planet will need to be treated as one and can own Cancer.
Clearly, humanity’s movement to Mars will be much more devastating to Astrology that movement to Moon, which is still in the neighbourhood. But wait, maybe there are aliens out there who have already mastered astrology as applicable to outside Earth birth and can teach us!