... The Moon (1) . ... The monthly cycle of the moon (we won't capitalize the word here) must have mystified early humans--"waxing" from thin crescent ("new moon") to half-moon, then to a "gibbous" moon and a full one, and afterwards "waning" to a crescent again. ... Early astronomers understood the different shapes of the moon, noting that each was linked to a certain relative position between moon and Sun: for instance, full moon always occured when moon and Sun were at opposite ends of the sky. ...

... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distance to the Moon or 1/100 the distance to the Sun--the spacecraft, too, will need just one year to go around the Sun, and will keep its position between the Sun and the Earth. ...

Educator's Guide to Eclipses . ... In a solar eclipse you observe the Sun (using only safe methods, of course). ... In a lunar eclipse you observe the Moon. ... Because of the geometry described below, you can only view a solar eclipse when the Sun is up, and the Moon is nowhere to be seen. ... Eclipses occur when the Sun, Earth and Moon line up. ... In a solar eclipse the Moon passes directly in front of the Sun. ... In a lunar eclipse the Moon moves into Earth's shadow. ...

Cosmic Research, Vol. 42, No. 5, 2004, pp. 435­488. Translated from Kosmicheskie Issledovaniya, Vol. 42, No. 5, 2004, pp. 453­508. Original Russian Text Copyright © 2004 by Veselovsky, Panasyuk, Avdyushin, Bazilevskaya, Belov, Bogachev, Bogod, Bogomolov, Bothmer, Boyarchuk, Vashenyuk, Vlasov, Gnezdilov, Gorgutsa, Grechnev, Denisov, Dmitriev, Dryer, Yermolaev, Eroshenko, Zherebtsov, Zhitnik, Zhukov, Zastenker, Zelenyi, Zeldovich, Ivanov-Kholodnyi, Ignat'ev, Ishkov, Kolomiytsev, Krasheninnikov, Kudela,