The occultation (obscuring) of one celestial body by another.

Solar and lunar eclipses take place at syzygies of the Sun, Earth, and Moon, when the three bodies are in a line. At a solar eclipse, the Moon blocks the view of the Sun as seen from the Earth. At a lunar eclipse, the Earth’s shadow falls on the Moon, darkening it, and can be seen from wherever on Earth the Moon is above the horizon.

The angles of a chart are the Ascendant (ASC) or degree ascending at the horizon, the opposite point, known as Descendent (DESC), the Medium Coeli (MC) and the Immum Coeli (IC).

The cusps of the First, Fourth, Seventh and Tenth Houses are on the ASC, IC, DESC and MC respectively and are highly personal and sensitive points. A planet positioned near these points becomes very important in chart interpretation and is said to be “angular”.

Radical position is the position of a given planet in the birth chart or radix. It is abbreviated R or r to be distinguished from the progressed or directed positions of the same planet.

But in Horary astrology, the term radical describes a horoscope that is fit to be judged.

In traditional astrology, this term refers to different situations where the energies of a planet are weakened or corrupt. In such situations, the planet finds great difficulty to express itself freely and in a positive way, as if it were in distress. A typical affliction is, for example, receiving a hard aspect – an opposition or square – from Saturn or Mars, traditionally regarded as Malefics, or from any other planet that is not compatible in nature. Another affliction is when a planet is “besieged”, being positioned between the two malefics.

In modern astrology, a planet is afflicted when it receives unfavourable aspects.

The point in a planet’s orbit where it it most distant to the Sun. The opposite point, where it is closest to the Sun, is called Perihelion.
The aphelion of the Earth occurs about 4th July each year.