the parallel plane, with its centre at the Earth's centre. This greatly simplifies the geometry of the horoscope, but does not take into account that the native is in motion. Some writers on astrology have thus considered the effects of parallax, but most would agree that (apart from that of the moon) they are relatively minor. Angles There are four primary angles in the horoscope which are thought to influence key areas and moments in a native’s lifetime, or within a given day or time. These are, in order of power: First House (Ascendant, East Angle, rising sign, or ASC/AC) Tenth House (Midheaven, Medi Coeli (midheaven), North Angle, MC) Seventh House (Descendant (astrology), West Angle, setting sign, DSC/DC) Fourth House (Imum Coeli – South Angle, lower-heaven, IC) The ascendant is the easternmost (or sunrise point) where the ecliptic and horizon intersect; the ascendant and the midheaven are considered the most important angles in the horoscope by the vast majority of astrologers. In most systems of house division, the ASC is the cusp of the 1st house and the MC is the cusp of the 10th house. Generally, on an astrological chart, each of these four angles are roughly 90° from the next, forming a cross shape (two oppositions, 180° each, forming a 360° sphere). This cross formation is made up of the points of east-west, north-south, or 1st house-7th house, 10th house-4th house (give or take, based on speed of orbit and degree). A simplistic comparison would be a clock face, with the 1st house and 7th house being placed at 9 and 3 o’clock, and the 10th and 4th houses placed at 12 and 6 o’clock, respectively. The placement of the planetary ruler of the ascendant, called the Chart Ruler, is also considered to be significant; The point in the west diametrically opposing the ascendant is called the descendant, normally the cusp of the 7th house; and the point opposing the MC is the cusp of the 4th house, the northernmost point of the chart, called the Imum Coeli or IC. In creating a horoscope, the ascendant is traditionally placed at the "nine o'clock" position on the left-hand side of the chart wheel (though traditional rectangular chart formats need not follow this convention). During the course of a day, because of the Earth's rotation, the entire circle of the ecliptic will pass through the ascendant and will be advanced