Intermediate Algorithm Scripting: Map the Debris

function orbitalPeriod(arr) {
  let GM = 398600.4418;
  let earthRadius = 6367.4447;
  let T;

  arr.map( (item, index) => {
    item.orbitalPeriod = Math.round( 2 * Math.PI * (Math.sqrt( Math.pow(earthRadius+arr[index].avgAlt , 3) / GM)) )
  })

  arr.map(item => delete item.avgAlt)
  
  return console.log(JSON.stringify(arr))
}

//orbitalPeriod([{name : "sputnik", avgAlt : 35873.5553}]);
orbitalPeriod([{name: "iss", avgAlt: 413.6}, {name: "hubble", avgAlt: 556.7}, {name: "moon", avgAlt: 378632.553}])