How big would the Sun appear if you were standing on Mercury?

Question

Compared to its appearance from Earth, how big would the Sun appear to an observer standing on Mercury?

Answer 1

The sun appears to be about 1/2 degree in size from the earth where the sky from horizon to horizon covers 180 degrees. If we just make it simple and for a quick calculation take it that the angular size is inversely proportional to the radial distance.

size = radius*angle

and the size is the same since it is the diameter of the sun.

r1*a1 = r2*a2 or a2 = a1*(r1/r2)

r1 = distance earth to sun = 98,000,000 miles (close enough)

r2 = distance mercury to sun = 36,000,000 miles (it varies quite a bit comared with earth and is in the apprximate range 29 to 43 million miles depending on where mercury is in it's orbit)

a2 = (1/2)(98000000/36000000) = (1/2)(98/36)

a2 = 1.36 degrees on average

at it's largest it would be a2 = (1/2)(98/29) = 1.7

on average the sun would appear to be about 1.4 degrees in size and at it's maximum around 1.7 degrees.

Compared with the sun from the earth:

(1.7/.5) = 3.4

So when mercury is closest to the sun, the sun would appear almost 3 and a half times larger than it does from the earth.

Answer 2

It'd fill the entire sky ... Simple as that.

Answer 3

Somewhat more than three times the size that it appears

to be when viewed from Earth.

Mercury is roughly 36,000,000 Miles from the Sun.

Earth is roughly 93,000,000 Miles from the Sun.

Someone said depends on the time of day...Pure Rubbish.

It does depend upon the time of year, because Mercury's

orbit is not a perfect circle - more of an elipse, and the

actual distance to the Sun varies somewhat.

Oh, just for the record, anyone standing upon the surface of

Mercury would be fried by the intense Gamma and X Ray

radiation, plus cooked way past "well done" by the elevated  surface temperatures there of Plus 806 Degrees F at noon,

and around Minus 300 Degrees F at night. If you are not

used to the F Temperature scale, Plus 32 Degrees is freezing and Plus 212 Degrees is Boiling at an atmospheric pressure of 14 PSI. And, of course, Mercury does not have an Earthlike atmosphere, so those temperature meanings are rather useless in comparison. Most of the gases which make up Mercury's atmosphere are lost into space due to the low gravity of the planet.

Answer 4

It would cover the whole sky...but you wouldn't be able to stand there for very long...you'd burn to a crisp, dry up and turn to dust.

Answer 5

That's an easy one:

Mean distance earth-sun:  d = 150 million km

Radius of the sun: r = 0.7 million km

angular diameter of sun = alpha

Now we want to know the angle of the mean angular diameter:

tan (alpha/2) = r/d

=> tan (alpha/2) = 0.7 * 10^6 / 150 * 10^6

resolve for alpha/2

=> alpha/2 = arctan(0.7/150)

=> alpha/2 = 0.26738°

angular diameter of the sun = alpha = 0.53476° or 32 arcminutes

The data for mercury:

mean distance mercury-sun: 58 million km

Mercury's orbit is more elliptical than Earth's orbit, so you can use 47 million km at the nearest (perihelion) and 69 million km at the farthest (aphelion) point from the sun.

tan (alpha/2) = 0.7 * 10^6 / 58 * 10^6

=> alpha/2 = arctan(0.7/58)

=> alpha/2 = 0.6915°

=> alpha = 1.3829° or 1° 23' (one degree and 23 arcminutes)

at the nearest point: alpha = 2* arctan(0.7/47) = 1.71° or 1° 42' 24"

at the farthest point: alpha = 2* arctan(0.7/69) = 1.16° or 1° 09' 45"

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Comparing both angles shows that on Mercury the sun looks approximately 2.2 to 3.2 times bigger than on earth.

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I'm using a simplifying formula. It's valid if the distance from the sun is a lot higher than the diameter of the sun.

If you want more precise values, use this formula:

r/d = sin (alpha/2)

=> alpha/2 = arcsin (r/d)

=> alpha = 2 arcsin (r/d)

The approximation I've used works because tan(a) is approximately sin(a) for small angles. Or calculating in radians instead of degrees: The tangent of the angle is approximately equal to the angle itself - for small angles.

You can check for yourself how big the difference between my simplification and the exact formula is. It's small.

Answer 6

from this site....

http://library.thinkquest.org/C002416/me...

"

CONDITIONS ON THE SURFACE:

     Since Mercury is the closest planet to the sun, it gets very hot on Mercury. Temperatures skyrocket to 801 Fahrenheit (427 Celsius) and dive to -279 F (-173 C) at night. The sun's rays are 7 times stronger on Mercury and the sun seems 2 ½ times bigger in Mercury's sky. That could cause one bad sunburn! Mercury doesn't have enough gases to reduce the heat and light it receives from the sun."

Answer 7

really big

Answer 8

The answer would be Distance from Earth / Distance of Sun from Mercury.

93 / 36 = 2.6

Sun will appear 2.6 times larger than what it seems on Earth.

Answer 9

it would be like putting a ball of fire in your face. x

Answer 10

Obviously a lot bigger, but a lot depends on what time of day/year you were looking at it.