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Sander Rossel wrote:

Is Sunn O))) metal?

Member 7989122 wrote:

You could e.g. watch an animation of any solar eclipse, as it would appear from any place on earth. You could plot the trajectories of any of the planets across the sky. You could generate caldendars containing exact times for any astronomical event for each day, such as sunrise/sunset, equinoxes, eclipses, and lots more.

// ******************************************************************************************
// Stellarium script to find the next next solar eclipse, to within specifiable radian
// difference of 'maxDiff'.
//
// Per NASA, Changes in ambient light are generally not noticeable until the sun is more
// than 95 percent covered by the moon.
// (https://www.nasa.gov/feature/goddard/2016/nasa-releases-march-8-total-solar-eclipse-
//  visualizations.)
//
// (If you watch shadow pinlights between tree leaves, you can see the crescent shape
//  of the eclipse at lesser percentages.)
//
// Created by David O'Neil, Aug, 2019. Released to the public domain, for anyone interested.
// Just leave this 'created by' (or 'originally created by') verbage in the derived work.
//
// To use:
//   * Set the date via Stellarium's user interface close to a time you are looking for a
//     solar eclipse to occur.
//   * To go backwards in time, change the 'dayDiff' variable accordingly.
//   * Run the script. It will stop executing when the 'maxDiff' condition is met.
// ******************************************************************************************

//Set the following to "-29 days" to go backwards:
dayDiff = "-29 days";
maxDiff = 0.004;

//Don't change anything below here:
obj1 = "Sun";
obj2 = "Moon";
a1 = 0.0;
a2 = 1.0;
pi = Math.PI;
degToRad = pi/180;

//map=core.getSelectedObjectInfo();
//core.output(core.mapToString(map));

core.selectObjectByName(obj1, true);
StelMovementMgr.setFlagTracking(true);
justFindSeparation = false;
diff = 1.0;
if (justFindSeparation) {
   d = getRadiansBetweenObjects();
   d = d/degToRad;
   degrees = Math.floor(d);
   minutes = d - degrees;
   minutes = minutes * 60;
   seconds = minutes - Math.floor(minutes);
   core.debug(degrees + " " + Math.floor(minutes) + " " + seconds*60);
   }
else {
   while (true) {
      while (diff > maxDiff) {
         findClosestConjunction();
         //core.wait(1);
         diff = getRadiansBetweenObjects();
         //core.debug(core.getDate() + ", Angle Diff: " + diff);
         if (diff >= maxDiff) core.setDate(dayDiff);
         }
      core.debug(core.getDate() + " " + diff);
      core.setDate(dayDiff);
      diff = 1.0;
      }
   // core.debug("Success!");
   // core.debug(core.getDate());
   // core.debug("Angle Diff: " + a2);
   }

function findClosestConjunction() {
   core.selectObjectByName(obj1, true);
   StelMovementMgr.setFlagTracking(true);
   core.setTimeRate(0); //Lock the sky in place, so we can see it unmoving!

   //Get the initial 2 points:
   a1 = getRadiansBetweenObjects();

   //Do initial iteration in 1-day increment:
   a2 = getTheAngleAfter("+1 days");

   direction = "+";
   if (a2 < a1) {
      direction = "+";
      }
   else {
      direction = "-";
      a2 = getTheAngleAfter("-2 days");
      }

   timeStepString = direction + "1 days";

   //Iterate:
   while (a2 < a1) {
      a1 = a2;
      a2 = getTheAngleAfter(timeStepString);
      }

   //Assume we've gone through several days, and have passed the last good one,
   //so step back (or forward) a day to fix the overstep:
   if (direction == "+") {
      a1 = getTheAngleAfter("-1 days");
      }
   else {
      a1 = getTheAngleAfter("+1 days");
      }

   //And the hour intervals. As before, we must check whether we need to
   //go back or forward.

   //Now determine whether to go forward or back:
   a2 = getTheAngleAfter("+1 hour");

   if (a2 < a1) {
      direction = "+";
      }
   else {
      direction = "-";
      a2 = getTheAngleAfter("-2 hours");
      }

   timeStepString = direction + "1 hour";

   while (a2 < a1) {
      a1 = a2;
      a2 = getTheAngleAfter(timeStepString);
      }

   //Assume we've gone through several hours, and have passed the last good one,
   //so step back (or forward) an hour to fix the overstep:
   if (direction == "+") {
      a1 = getTheAngleAfter("-1 hours");
      }
   else {
      a1 = getTheAngleAfter("+1 hours");
      }

   if (a2 > 0.04) return;

   //And the 20 minute intervals:
   //First, set a1 to a2, as a2 was last measurement taken at current time:
   a1 = a2;
   a2 = getTheAngleAfter("+20 minutes");

   if (a2 < a1) {
      direction = "+";
      }
   else {
      direction = "-";
      a2 = getTheAngleAfter("-40 minutes");
      }

   timeStepString = direction + "20 minute";

   while (a2 < a1) {
      a1 = a2;
      a2 = getTheAngleAfter(timeStepString);
      }

   //And the 5 minute intervals:
   //First, set a1 to a2, as a2 was last measurement taken at current time:
   a1 = a2;
   a2 = getTheAngleAfter("+5 minutes");

   if (a2 < a1) {
      direction = "+";
      }
   else {
      direction = "-";
      a2 = getTheAngleAfter("-10 minutes");
      }

   timeStepString = direction + "5 minute";

   while (a2 < a1) {
      a1 = a2;
      a2 = getTheAngleAfter(timeStepString);
      }

   //And finally, for the minutes:
   //First, set a1 to a2, as a2 was last measurement taken at current time:
   a1 = a2;
   a2 = getTheAngleAfter("+1 minutes");

   if (a2 < a1) {
      direction = "+";
      }
   else {
      direction = "-";
      a2 = getTheAngleAfter("-2 minutes");
      }

   timeStepString = direction + "1 minute";

   while (a2 < a1) {
      a1 = a2;
      a2 = getTheAngleAfter(timeStepString);
      }

   }

function getTheAngleAfter(timeStep) {
   obj2Azi = core.getObjectInfo(obj2).azimuth;
   core.setDate(timeStep);
   while (core.getObjectInfo(obj2).azimuth == obj2Azi) {
      core.wait(0.01);
      }
   angleDiff = getRadiansBetweenObjects();
   return angleDiff;
   }

function getRadiansBetweenObjects() {
   obj2Azi = core.getObjectInfo(obj2).elong;
   obj2Azi = obj2Azi * degToRad;
   obj2Alt = core.getObjectInfo(obj2).elat;
   obj2Alt = obj2Alt * degToRad;

   obj1Azi = core.getObjectInfo(obj1).elong;
   obj1Azi = obj1Azi * degToRad;
   obj1Alt = core.getObjectInfo(obj1).elat;
   obj1Alt = obj1Alt * degToRad;

   d = Math.acos(Math.sin(obj2Alt)*Math.sin(obj1Alt)+Math.cos(obj2Alt)*Math.cos(obj1Alt)*Math.cos(obj2Azi-obj1Azi));

   //The following formula is for when the objects are very close together, or very close to 180 degrees apart:
   //I may have Azi and Alt mixed up.

   // delAzi = obj1Azi - obj2Azi;
   // delAlt = obj1Alt - obj2Alt;

   //d = sqrt ( (cos(aziA-aziB) * (altA-altB)) ^2 + (aziA-aziB)^2 )
   //d = Math.sqrt ( Math.cos(delAzi)*(delAlt) * Math.cos(delAzi)*(delAlt) + (delAzi)*(delAzi) );

   return d;   //In radians
   }