At complete lunar eclipse, this angle is 180°. As age of moon increases, its elongation increases and it becomes more visible at greater elongations. The moon does not always start with 0° elongation; its elongation can be up to 5° at time of its birth. So such a moon that starts at maximum elongation can be sighted at younger ages. The steep angle means the Moon's altitude will be greater just after sunset. Ignoring local conditions for the moment and visualizing the problem from outside the Earth's atmosphere, the size and brightness of the lunar crescent depend on only one astronomical quantity: the elongation of the Moon from the Sun, which is the apparent angular distance between their centers.
This diagram shows various possible elongations (ε), each of which is the between a and the from Earth's perspective.In, a planet's elongation is the between the and the planet, with as the reference point. The greatest elongation of a given occurs when this planet's position, in its path around the Sun, is at to the observer on Earth. Since an inferior planet is well within the area of around the Sun, observation of its elongation should not pose that much a challenge (compared to, for example).
When a planet is at its greatest elongation, it appears farthest from the Sun as viewed from Earth, so its apparition is also best at that point.When an inferior planet is visible after, it is near its greatest eastern elongation. When an inferior planet is visible before, it is near its greatest western elongation.
The angle of the maximum elongation (east or west) for is between 18° and 28°, while that for is between 45° and 47°. These values vary because the planetary orbits are rather than perfectly. Another factor contributing to this is, in which each planet's is slightly tilted relative to a, like the and.and websites, such as, forecast when and where the planets reach their next maximum elongations.