During the next twenty, thirty or sixty days after birth the planets move on and make certain aspects to the positions held by them at birth. Each of these days corresponds to a year of life, and the aspects formed by the ‘progression’ on the twentieth day after birth will operate to bring about events in the twentieth year. The aspects formed on the thirty-fifth day after birth will determine the influences in the thirty-fifth year and go on. These are called ‘progressed’ positions and aspects. Thus, if someone says “my progressed Sun will be trine to my radical Jupiter when I am forty,” he means that forty days after his birth the Sun had progressed to a trine aspect with the position of Jupiter at his birth, and that therefore this will operate in his fortieth year to bring about events of a fortunate nature, because the aspect and the planets are what is called good.
As the span of life is usually not more than seventy years, the planetary positions after seventy days from birth do not have as marked an effect as described in the foregoing paragraph, but they have nevertheless an appreciable influence on the lives of mankind, according to their natures. But because of the rapid transit made, the effects are ephemeral, even in the case of the slower planets. These movements of the planets are called ‘Transits.’
They are found in the ephemeris for the current year. That is to say, if you want to know what planets transit the different houses of your horoscope in
