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...

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

May 3, 2020 · 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

Feb 15, 2017 · 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 …

Feb 15, 2011 · Do you want to know both how the Earth-sun distance is measured and how the speed of light is measured? Those are completely different things. As I asked before, separate threads, please.

The Sun's energy comes primarily from fusion of light elements in its core. It is estimated that a very small fraction of mass of the Sun (~$10^{-12}$ times the abundance of hydrogen) is uranium (b...

Apr 17, 2015 · 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 …

Aug 27, 2015 · The sun outputs about 1300 watts per square meter (W/m²) in space near the earth, which gets reduced to around 650 W/m² in the middle of the day after going through the atmosphere. …

The sun's spectrum is very complex, and indeed there are a lot of "lines"—both light and dark (emission and absorption)—amidst a sea of what looks to be continuous frequencies.

Apr 28, 2020 · The Sun was certainly much faster rotating in the past. When it was 100 million years old it likely had a rotation period somewhere between 0.5 and 5 days (observed in solar analogues at …