Here are some useful calculations about pixels width and height in Miles, Meters, etc.
| | d| | | h\ PX R EarthHere, we have:
d = R * tan(h)
Where:d is the distance in length units, such as Sun-Pluto, or miles.
R is the distance between PX and Earth, same units as d.
h is the angel in degrees at Earth side.Since each frame is 1024*1024 pixels, and the field of view is 23.6*23.6 Arcminutes, each pixel represents 3.8411458333333e-4 Degrees.
Assuming that PX is at 3 SunPluto,
Given:
R = 3 SunPluto
h = 3.8411458333333e-4 Degrees
AU = 1.496e11 Meters
SunPluto = 39.91136 AU = 5.970739456e12 Meters = 3.71004549431e+9 Miles
EarthMoonDistance = 3.844e8 MetersPixel Size:
d = R * tan(h) = 3 * tan(3.8411458333333e-4) = 2.0112192552579e-5 SunPluto = 8.0270495735532e-4 AU = 1.2008466162035e+8 Meters = 120084.66162035 KM = 74617.149360458097 Miles = 0.312395 EarthMoonDistance
Moons tail size in pixels:
From existing ZetaTalk:
- You can consider the Moons to be within 5 million miles of Planet X, as the maximum distance they will stray.
- ZetaTalk
- Maximum Moons tail size at 3 SunPluto = 5e6 / 74617 = 67 Pixels
Note: This is a 2 D distance, not a 3 D distance. We are looking at a projection of 3 Dimensional objects into a 2 D surface. If 2 objects are behind each other, and one is slightly to the side, then you cannot really tell how far apart are they by looking at a 2 D image.
Naji