Recent comments in /f/space

db720 t1_j6ggkts wrote

I guess where the force that stops it gets applied. Imagine the core halting so the crust momentum causes it to slide of the mantle. Massive quakes.

Dark side would definitely get cold once everything settled, below freezing for sure, and sunny side roasted worse than any desert.

Only dusk / dawn zones would be habitable

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tbodillia t1_j6gcnuc wrote

Tidally locked and not rotating are 2 different things. The Moon is tidally locked to the Earth so we only see one face. The Moon rotates once every 27 days and orbits us once every 27 days. Mercury is tidally locked to the Sun.

Pick up a ball and have it "orbit" a lightbulb at home. A solar day (noon to noon) should be a year.

"Dark side" of the moon is a misnomer. All sides receive the same amount of sunlight. It's just generally people automatically assume the far side is always dark, and movies don't help.

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Niven42 t1_j6gb84p wrote

The Sun's absolute magnitude (how bright it would appear at a distance of 10 parsecs), is about +4.83, which means that out to around 30 light years, it appears as a fifth magnitude star or brighter. Although there are many factors to how bright stars appear while observing from Earth, the classic constellations were limited to around fifth magnitude, or brighter (magnitude is an inverse scale; smaller numbers are brighter). So, for at least all systems out to around 10-12 parsecs, the Sun is bright enough to be included in their constellations (if they used the same criteria as our ancients did when creating star groupings).

Here is a chart of around 130 star systems where the Sun would be likely to appear as a significant constellation star.

http://www.icc.dur.ac.uk/~tt/Lectures/Galaxies/LocalGroup/Back/50lys.html

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