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Why would a Moon base need fresh supplies even if it recycles?

A recycling system can recover nearly all its water and still need replacement supplies. NASA reported a 98% recovery milestone on the International Space Station in 2023; a small unrecovered share adds up as water circulates. An imagined Moon base makes the difference between the water initially stored and the water continually lost easier to see.

3–5 min

Questions you could explore

  • Which losses could a larger starting supply postpone without eliminating?

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Space

Why does the Moon change shape during a month?

A crescent Moon is not a partly switched-off Moon. Sunlight still illuminates half of it, while its changing position around Earth changes how much of that lit half we can see.

3–5 min
Space

Two eclipses, two different shadows

A solar eclipse and a lunar eclipse both involve the Sun, Earth, and Moon, but the shadow falls in a different place. In one, the Moon’s shadow reaches Earth; in the other, the Moon moves into Earth’s shadow. The Moon’s tilted orbit helps explain why these alignments do not happen every month.

5–7 min
Space

What can a century-old photograph tell us about a changing sky?

An old astronomical glass plate preserves an observation that cannot be made again today. Harvard’s plate archive brings such records into digital comparison, alongside dates, logbooks, and calibration work. The glass image alone is not the whole dataset; knowing how and when it was made changes what can be inferred from it.

8–10 min
Why would a Moon base need fresh supplies even if it recycles? | Speech Topic | speaking.app