The Sidereal Zodiac aligns with the constellations when we look up to the sky. This system is different from the Tropical Zodiac, which aligns itself with the seasons of Earth. This difference is due to the precession of Earth's oval orbit rather than perfectly circular. Over time, the two systems have grown apart by approximately 23 degrees of solar arc. Although there are many similarities, there are subtle differences in the meaning of the signs between the two systems. In Vedic astrology, the signs strongly associate with the houses they naturally rule—Aries - 1st house, Taurus 2nd house, and so on.