6 votes
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Can Mercury be seen from the 60th parallel north on Earth? Shetland, Faroe, Norway, St Petersburg, Alaska

Yes it can be seen, but as the angle of the ecliptic is lower in more Northern Latitudes it is harder to see. Chris Brown of the Shetland times writes in Feb 2000: February brings a chance to try and ...
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6 votes
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Can Jupiter's rings be seen with the naked eye by an astronaut nearby? How difficult would it be?

Here is an answer based on photometric arguments: The astronaut probably would not be able to see the rings, but it would be worth a try. I would recommend the astronaut float somewhere at a distance ...
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4 votes

What would be the highest possible naked-eye apparent magnitude?

There has been a series of papers regarding this throughout the first half of the last century. According to an extensive review paper by H.F. Weaver the limiting magnitude under ideal conditions is ...
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4 votes

What would be the highest possible naked-eye apparent magnitude?

This is probably not answerable in simple terms. Generally, magnitude 6 is the limit of normal vision under ideal conditions, though some have reported seeing objects dimmer than this. Julius Schmidt ...
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3 votes

Back when the CMB was predominantly in the visible spectrum, would it have been visible to the naked eye?

It wouldn't be like staring into the Sun so much as being inside the Sun (its photosphere, anyway). What we really see is not distant objects, but light that enters our eyeballs. The CMB radiation ...
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3 votes

Back when the CMB was predominantly in the visible spectrum, would it have been visible to the naked eye?

The cosmic microwave background (CMB) was emitted as a blackbody at a temperature of about 3000 K. The CMB temperature then falls as the universe expands and is currently at a temperature of 2.73 K. ...
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2 votes

Can Jupiter's rings be seen with the naked eye by an astronaut nearby? How difficult would it be?

Here is a separate answer based on a couple of visible light images. It looks like the astronaut has a very good chance of seeing the rings. A. A wide angle image, taken from inside the ring by Juno'...
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  • 1,774
2 votes

Can Mercury be seen from the 60th parallel north on Earth? Shetland, Faroe, Norway, St Petersburg, Alaska

I am the OP, and I can confirm it, I've just seen Mercury from shetland, 31st october 2021 6 am local time. Apologies for posting this on another answer, but I am so excited and happy about it, almost ...
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2 votes
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What percentage of meteors are visible to the naked eye?

Meteors caused by small objects are visible. Most visible [meteors are produced by meteoroids, which] are between 1 mm and 1 cm in diameter. For example, a meteor of magnitude +5, which is barely ...
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2 votes

What percentage of meteors are visible to the naked eye?

The naming must first be defined. Meteoroid: A rock orbiting the Sun. Meteor: When a meteoroid enters a planet's atmosphere it becomes a meteor. This is what we see streaking across the sky, mostly ...
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