Download or view drawJupiterSaturn.frink in plain text format
/** This draws the great 2020 conjunction of Jupiter and Saturn for any given
date. Try:
frink drawJupiterSaturn.frink "2020-12-21 06:00 PM"
for what is probably the closest visible nighttime approach for
Denver, Colorado, USA
You will need the 2020-08-09 release of planets.frink for this to work
correctly.
*/
use planets.frink
lat = 40 deg North
long = 105 deg West
if length[ARGS] > 0
d = parseDate[ARGS@0]
else
d = now[]
[jaz, jalt] = Planet.Jupiter.refractedAzimuthAltitude[d, lat, long]
[saz, salt] = Planet.Saturn.refractedAzimuthAltitude[d, lat, long]
jrad = Planet.Jupiter.radiusAngle[d]
srad = Planet.Saturn.radiusAngle[d]
// Center on Saturn (because it moves the slowest in the sky)
g1 = Planet.drawSaturnRelativeToZenith[d, lat, long, (saz-saz) cos[-salt], -(salt-salt), srad, true, true]
g2 = Planet.drawJupiterMoonsRelativeToZenith[d, lat, long, (jaz-saz) cos[-salt], -(jalt-salt), jrad, true, true]
g = new graphics
g.add[g1]
g.add[g2]
g.invertGrays[].show[]
g.invertGrays[].write["drawJupiterSaturn.png", 1024, undef]
g.print[]
Download or view drawJupiterSaturn.frink in plain text format
This is a program written in the programming language Frink.
For more information, view the Frink
Documentation or see More Sample Frink Programs.
Alan Eliasen, eliasen@mindspring.com