astronomy - How big a coincidence is the Sun and Moon having almost ...

It's consensus that the very similar apparent sizes of the Moon and the Sun as seen from Earth is a coincidence (as already answered in this site). This provides us with almost exact total solar

How much lux does the Sun emit? - Physics Stack Exchange

I want to know how much lux the sun emits on a bright day - I don't mean when one stares directly at the sun, but rather when one walks casually outside when the sun is shinning brightly. Now the

What is the simplest way to prove that Earth orbits the Sun?

Assume you're talking to someone ignorant of the basic facts of astronomy. How would you prove to them that Earth orbits the Sun? Similarly, how would you prove to them that the Moon orbits Earth?

Why doesn't sun go all the way to the horizon during sunset?

Everytime I see the pics of suset on beaches the sun appear to go all the way down to the surface of the sea (as shown in the picture) but when I see sunset in my region , the sun disappears well above the horizon. Why does that happen ? EDIT :- A better picture of the sunset.

How long until the sun cannot sustain human life on earth?

The sun will last, at its current brightness for 9 billion more years. How long until the sun gets burned down to the point where it cannot sustain life on Earth anymore? Updated: I am more concer...

What would happen if Jupiter collided with the Sun?

This question is inspired by a similar one asked on Quora. Let's say a wizard magicked Jupiter into the Sun, with or without high velocity. What happens? The Quora question has two completely oppo...

astrophysics - Why wouldn't the part of the Earth facing the Sun a half ...

Over half a year, this nearly 4 minute difference every day adds up to about 12 hours, the time it takes to rotate half way around and face the sun again. 24 hours is the length of the average solar day (Synodic Day), the time it takes the earth to rotate so that (on average) it is facing the sun at the same angle.

How is Earth protected from the gamma rays generated by the Sun?

The Sun is generating energy by nuclear fusion. This nuclear fusion will emit energy in the form of gamma rays. Normally, the earth's ozone layer filters the ultraviolet radiation while the earth's

Is the distance between the Sun and the Earth increasing?

Besides the moon, the sun has a tidal component for the earths oceans, and when that crashes into continents the energy absorbed comes from the potential energy of the sun-earth system. I am not sure how this compares to the distance loss due to the mass and energy radiation of the sun you mentioned.

What is actually meant by 'sun set' and 'sun rise' times, when taking ...

If this is the case, then when we read things like what time sun sets and rises on websites, books, calendars, other official times, et al… does that mean when we see for example ‘sun set at 18:35’ is the time denoting the actual sun set taking into account of the mirage or what is visible to us.