abracadabra 发表于 2025-3-26 23:49:10

The Planet Saturn,0 000km and a mass of 95 times that of the Earth. The average density of Saturn is a mere 700kg/m., less dense than water! Saturn moves through the Solar System at a mean distance of 1400 million km from the Sun, taking 29½ years to complete one orbit.

LATE 发表于 2025-3-27 01:31:57

http://reply.papertrans.cn/63/6255/625401/625401_32.png

是剥皮 发表于 2025-3-27 07:39:01

http://reply.papertrans.cn/63/6255/625401/625401_33.png

比目鱼 发表于 2025-3-27 12:10:39

http://reply.papertrans.cn/63/6255/625401/625401_34.png

SOBER 发表于 2025-3-27 16:57:58

http://reply.papertrans.cn/63/6255/625401/625401_35.png

Spongy-Bone 发表于 2025-3-27 21:08:00

http://reply.papertrans.cn/63/6255/625401/625401_36.png

infelicitous 发表于 2025-3-28 00:05:08

http://reply.papertrans.cn/63/6255/625401/625401_37.png

鄙视 发表于 2025-3-28 05:52:21

http://reply.papertrans.cn/63/6255/625401/625401_38.png

羊齿 发表于 2025-3-28 09:23:19

The Earth and Time,outhwards (the converse is true for people living in the southern hemisphere). More commonly known is the phenomenon of a ship travelling away from the shore disappearing from view whilst its sails are still visible above the horizon. The sails are then seen to ‘sink’ below the horizon as the ship further recedes.

注视 发表于 2025-3-28 10:41:44

http://reply.papertrans.cn/63/6255/625401/625401_40.png
页: 1 2 3 [4] 5 6 7
查看完整版本: Titlebook: Mastering Astronomy; Gerald North Book 1988 Gerald North 1988 astronomy.comet.cosmology.earth.gravitation.Jupiter.planet.quasar.solar syst