Observing the Universe
完成条件
按索引浏览词汇表
特殊 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 全部
L
Light-gathering powerA telescope's ability to collect light, which increases with the area of its main lens or mirror. | |
Light-YearThe distance light travels in one year (about 9.46 trillion kilometres). | |