// Magic Numbers

function orbitalPeriod(arr) {
    const a = 2 * Math.PI;
    const newArr = [];
    
    const getOrbPeriod = function(obj) {
        const c = Math.pow(6367.447 + obj.avgAlt, 3);
        const b = Math.sqrt(c / 398600.4418);
        const orbPeriod = Math.round(a * b);
        delete obj.avgAlt;
        obj.orbitalPeriod = orbPeriod;
        
        return obj;
    }
    
    for (elem in arr) {
        newArr.push(getOrbPeriod(arr[elem]))
    }
    
    return newArr;
}