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Evolution of the solar luminosity, radius and effective temperature compared to the present-day Sun. After Ribas (2009) [3] The uncrewed SOHO spacecraft was used to measure the radius of the Sun by timing transits of Mercury across the surface during 2003 and 2006. The result was a measured radius of 696,342 ± 65 kilometres (432,687 ± 40 miles).
Average distance of Earth's orbit from the Sun (sunlight travels for 8 minutes and 19 seconds before reaching Earth) — Mars: 1.52 — Average distance from the Sun — Jupiter: 5.2 — Average distance from the Sun — Light-hour: 7.2 — Distance light travels in one hour — Saturn: 9.5 — Average distance from the Sun — Uranus: 19.2 ...
The angular diameter of the Earth as seen from the Sun is approximately 1/11,700 radians (about 18 arcseconds), meaning the solid angle of the Earth as seen from the Sun is approximately 1/175,000,000 of a steradian. Thus the Sun emits about 2.2 billion times the amount of radiation that is caught by Earth, in other words about 3.846×10 26 watts.
The solar zenith angle is the zenith angle of the sun, i.e., the angle between the sun’s rays and the vertical direction.It is the complement to the solar altitude or solar elevation, which is the altitude angle or elevation angle between the sun’s rays and a horizontal plane.
Summer days are longer than winter days, but the difference is no more than approximately two and a half hours. The daily path of the Sun is steep at the horizon the whole year round, resulting in a twilight of only about one hour and 20 minutes in the morning and in the evening. Solstice day arcs as viewed from 50° latitude.
The Sun has been an object of veneration in many cultures. It has been a central subject for astronomical research since antiquity. The Sun orbits the Galactic Center at a distance of 24,000 to 28,000 light-years. From Earth, it is 1 astronomical unit (1.496 × 10 8 km) or about 8 light-minutes away.
The Sun is said to be extremely noisy, but we can’t hear it since sound doesn’t travel through space.
This means that the Sun is (a mean of) 6 + 3 ⁄ 4 times wider than the Earth, or that the Sun is 13 + 1 ⁄ 2 Earth-radii wide. The Moon and Sun must then be 20 + 1 ⁄ 4 and 387 Earth-radii away from us in order to subtend an angular size of 2º.