An astronaut in low Earth orbit moves in (approximately) a big circle extending around the Earth. ... That can be interpreted as stating that in the astronaut's frame of reference, all bodies are subject to two forces, gravity and the centrifugal force, and the two are in perfect balance, adding up to zero. ... Wheel-shaped space . ... The science-fiction film "2001: A Space Odyssey" featured spinning space station, whose rotation provided the crew with "artificial gravity." ...

... Historical Data . Orbital Data . Physical Data . ... Sun . ... 0.06 . ... 7.77e+17 . ... Key: Name Name of the planet or satellite. ... Distance Distance to the Sun or to the planet center. ...

... The Moon (1) . ... At any time, only half of the Moon's surface is visible from Earth, but librations allow us to "peek around the edges." ... Just as the rotation axis of the Earth is inclined by (90њ?23.5њ) to the Earth-Sun direction ( drawing above , from section #3 "Seasons of the year"), so the rotation axis of the Moon is inclined by about (90њ?6.5њ) to the mean Moon-Earth line. ... When it speeds up, the rotation of the Moon-Earth line around the Earth (measured in degrees per hour) is faster...

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,