MongoDB aggregate Query from mongodb university course

I’m currently studying MongoDB from MongoDB University’s free online courses.

Well, I’m working on part aggregation and tried writing aggregation query for the tutorial.

// This is what I wrote 

db.solarSystem.aggregate([{
  "$match": {
    "atmosphericComposition": { "$in": [/02/]},
    "meanTemperature": { $gte: -40, "$lte": 40 }
  }
}, {
  "$project": {
    "_id": 0,
    "name": 1,
    "hasMoons": { "$gt": ["$numberOfMoons", 0] }
  }
}], { "allowDiskUse": true})




// This is what's given as solution
db.solarSystem.aggregate([{
  "$match": {
    "atmosphericComposition": { "$in": [/O2/] },
    "meanTemperature": { $gte: -40, "$lte": 40 }
  }
}, {
  "$project": {
    "_id": 0,
    "name": 1,
    "hasMoons": { "$gt": ["$numberOfMoons", 0] }
  }
}], { "allowDiskUse": true});

Well, for me those two look identical! but the one that I wrote wont print out the solution 🙁

Could anyone tell me whats wrong with mine?
Thanks !

this is the sample db
mongo "mongodb://cluster0-shard-00-00-jxeqq.mongodb.net:27017,cluster0-shard-00-01-jxeqq.mongodb.net:27017,cluster0-shard-00-02-jxeqq.mongodb.net:27017/aggregations?replicaSet=Cluster0-shard-0" –authenticationDatabase admin –ssl -u m121 -p aggregations –norc