Eclipse

Things to remember

• The moon completes one revolution around the earth in about 27.33 days (27 days, 73 hour, 43 minutes and 11.5 second). This period is called sidereal month.
• The time taken by the moon to come from m1 to m3 condition is called synodic month or a lunar month. Thus, the duration between two consecutive new moons is synodic month.
• The umbra causes total eclipse and penumbra causes partial eclipse.
• When the moon passes directly between the earth and the sun, it blocks the sun. It casts the shadow some part or all the part of the sun is not seen. It is called solar eclipse.
• When the earth passes directly between the moon and the sun. It obstructs the light of the sun. The earth casts its shadow on the moon and the moon darkens partially or completely. It is called lunar eclipse.