Eclipses

Eclipses have been fascinating people since time immemorial to present day; in the old days, their sudden presence was never predicted and the effect on the masses, quite understandably, may have caused pandemonium.

Failing to comprehend these celestial events, our distant forefathers attached a mystic importance to them - about what was to come - ranging from mild chaos to doom's day scenarios. Even in the 21^st, we are not short of people who still think they are astrologically significant, when scientists debate their astronomical importance. Let's explore the simple science behind them ignoring the superstition.

There are two types of eclipses:

Solar Eclipse

Solar eclipse takes place when the sun, earth and moon happen to be in the same plane with the moon being in the middle, shadowing the sun. The effect is that people in some parts of the earth, do not see the sun or part of it. This phenomenon is called a solar eclipse.
Solar eclipse happens on new moon days. However, it does not happen on every new moon day, as it is very rare that these three heavenly-objects lie in the same plane. This is the reason that the arrival of a full solar eclipse leads to a hysterical break-out of  enthusiasm among masses - of astronomical proportions, of course - defying both intellect and geographical barriers.

The animation sums up that all.

Lunar Eclipse

Lunar eclipse takes place when the earth happen to be moving between the sun and moon, while all three objects are in the same plane. As a result, the earth blocks the arrival of sunlight which otherwise falls on the moon. Being a non-luminous object by nature, the moon does not light up itself and appears to us as a dark object, losing both its charm and gentle presence. This is called a lunar eclipse
It has been reported that people with obvious psychological problems show some sensitivity to this event. So a derived word, but with a rather unpleasant ring to it - of course, it is lunacy to beat about the bushes - resonates with the event in some quarters of the globe; anyway, this event has been fascinating our ancestors as well, from time immemorial, sometimes even triggering off torrents of superstition.
Lunar eclipses take place on full moon days.
The animation shows how it happens.

Please answer the following questions.

1) You cannot expect to see eclipses on Venus. Explain.
2) It is dangerous to look at a solar eclipse with a naked eye. Explain.
3) We get a full moon day once in every month, but not a lunar eclipse. Explain.
4) Eclipses can be explained by rectilinear propagation of light. Discuss.
5) Discuss the impact on earth, when the moon is in its penumbra and umbra regions of the shadow.
6) Compare and contrast our only natural satellite with an artificial satellite.
7) What is light year? Calculate the distance between the moon and the earth in terms of light years.