When two or more planets occupy the same sign while transiting through the zodiac to form an auspicious or, at times, inauspicious combination is called ‘Grah Yog’ or ‘Yuti’ in astrological terms. This situation happens frequently in the sky when two or more planets enters into one sign and confers positive as well as negative results, varying from person to person or it can be said, sign to sign. When naturally benefice planets combine together they become more auspicious and bestow assertive results as an outcome. When one benefic planet joins a malefic planet then the benefic planet loses its auspiciousness up to a certain extent depending on the sign they are travelling in and the influences, both, positive and negative, of other planets on them.
For example, let us talk about combination of the Sun and Moon together in a sign. Whenever this combination happens, it has to be the day of new Moon, that means Amavasya tithi, when the Moon is not at all visible in the sky and thus, weak. Actually, any planet comes closer to the Sun, within approximately 11 degrees, becomes combust because of the bright rays of the Sun. The outcome of this combination of the Sun and Moon normally makes one to trade in iron or stones. It gives fine artistic talent as well as ability to sculpture and gives knowledge of Vastu Shashtra also.