Mars Weather and how to fetch the data

What's the weather on Mars? Aside from drilling holes and collecting samples from the Martian surface, it is vital to keep tabs on the environmental information. I'm sure it's not all sunny all throughout a Martian year. If at all sunny, what could be the temperature and how the atmospheric variation for each Sols. Mars rover have to capture information such as these. It would be helpful to future missions on how the seasons on Mars varies and how could future rovers or even human missions sustain such a fluctuation with minimal disruption.

This is not a technical article of analyzing Mars Weather. Instead, as hobbyist, I'm going to share on how to fetch such information for personal or education purposes. But, before we dive into the "how" here's a short background on the REMS.

How we can take hold of such weather data?

With API we can get these information or data. The question is what API. NASA open API have published for InSight: Mars Weather. With Curiosity REMS, it's not openly shared. But, here, I will show you how. If you'll look into Mars MSL Curiosity REMS page. Inspect the webpage at the right element you will see the API they are currently using to create the weather information posted on the page as shown below.

The API URL is https://mars.nasa.gov/rss/api/?feed=weather&category=msl&feedtype=json. Opening this link will direct you to a page which contains all weather data since Sol 1. That's almost 3000 lines of data, considering is about Sol 3073 on Gale Crater Mars. You can always get down to coding and create ways to fetch those JSON data into usable and structured table. A .csv or directly written into a spreadsheet.

This approach is for script written in Google Apps Script. What's about to be shown are methods on...

1. How to fetch the REMS Curiosity data and write accordingly the latest Sol info into a spreadsheet.
2. Fetch like an online API where you can pick the information you only need. The API show above is not clearly mapped and no documentation available (found) to properly access the resources. Creating the API for you from the daily fetch done from the main API will be convenient for developers who just want the direct data right away. 

To save you time, you can access the full script on this github link https://github.com/git-janus/tracking_perseverance/blob/master/Mars_Weather_API_custom.js. Here are snippets of the code. Apologies for some image may not be clear enough. But, you may go ahead use above github link for better view of the code. As of the moment, it only caters with MSL Curiosity REMS data. I was hoping that I could find the API for Perseverance MEDA. Until such time we can have another attributes to our tracking percy as it searches for clues on Mars.

The script:

	var api_url = 'https://mars.nasa.gov/rss/api/?feed=weather&category=msl&feedtype=json'
	var ss = SpreadsheetApp.openById('XXXXXXXXX-YOUR-TARGET-GOOGLE-SHEET-ID-HERE-XXXXXXXXX');
	var ws_msl = ss.getSheetByName('Weather_Data_MSL_Curiosity');//YOU CAN HAVE YOUR CUSTOMER TAB/SHEET NAME HERE FOR CURIOSITY REMS DATA
	var ws_percy = ss.getSheetByName('Weather_Data_Perseverance');//YOU CAN HAVE YOUR CUSTOMER TAB/SHEET NAME HERE FOR PERSEVERANCE MEDA
	var api_data = [];
	/**
	* FETCH THE ALL WEATHER DATA FROM API URL
	*/
	function fetch_weather_data(api_url){
	var response = UrlFetchApp.fetch(api_url);
	var json = response.getContentText();
	var data = JSON.parse(json);
	var weather_data = data.soles;
	return weather_data;
	}
	/**
	* THIS FUNCTION IS INTENDED TO FETCH A LINE OF SOL WEATHER DATA AND WRITE/APPEND IT TO SPREADSHEET
	* THIS WILL TAKE LONG IN THIS APPROACH. IF YOU'RE STARTING FROM SCRATCH, RECOMMEND TO CREATE A SINGLE
	* ARRAY THEN WRITE THEM AT ONCE TO SPREADSHEET WITH .GETRANGE().SETVALUES(ARRAY) METHOD.
	*/
	function bulk_fetch_weather_data(){
	var weather_data = fetch_weather_data(api_url);
	var ws_db = ws_msl.getDataRange().getValues();
	var last_sol_ws_db_recorded = ws_db[ws_db.length - 1][2];
	weather_data.map(function(el){
	if(el.sol > last_sol_ws_db_recorded){
	var row = [
	el.id,
	el.terrestrial_date,
	el.sol,
	el.ls,
	el.season,
	el.min_temp,
	el.max_temp,
	el.pressure,
	el.pressure_string,
	el.abs_humidity,
	el.wind_speed,
	el.wind_direction,
	el.atmo_opacity,
	el.sunrise,
	el.sunset,
	el.local_uv_irradiance_index,
	el.min_gts_temp,
	el.max_gts_temp
	]
	ws_msl.appendRow(row);
	}
	});
	}
	//
	/**
	* ROVER ENVIROMENTAL MONITORING STATION (REMS)
	* CUSTOM API. TO PROCESS FURTHER AND SOMEHOW RECREATE THE WEB STRUCTURE AS SHOWN ON THIS PAGE - https://mars.nasa.gov/msl/spacecraft/instruments/rems/
	* CHECK THE SCRIPT USED ON THE SAME WEBSITE/PAGE = https://mars.nasa.gov/js/general/weather/msl-weather.js
	* CREATED BY TRACKING PERSEVERANCE
	* WEBSITE: www.trackingperseverance.com
	* FACEBOOK: www.facebook.com/trackingperseverance
	* CONTACT: info@trackingperseverance.com
	*/
	function doGet(e){
	var manifest = e.parameter.manifest;
	var rover = e.parameter.rover;
	var sol = e.parameter.sol;
	var min_sol = e.parameter.min_sol;
	var max_sol = e.parameter.max_sol;
	if(manifest === 'yes'){
	data = fetch_manifest();
	}else{
	if(rover === 'Curiosity'){
	data = fetch_rover_data(rover,sol,min_sol,max_sol);
	}
	}
	return ContentService.createTextOutput(JSON.stringify(data)).setMimeType(ContentService.MimeType.JSON);
	}
	/**
	* MANIFEST - GENERAL INFORMATION ABOUT ROVER REMS DATA CALL.
	* RETURNS ROVERS INCLUDED IN THE API AND ITS CORRESPONDING PARAMETERS NEEDED/AVAILABLE FOR QUERY
	* RETURNS MAX SOL OR LATEST SOL CAPTURED
	* RETURNS SUPPORTED CALLS:
	* MANIFEST : https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?manifest=yes
	* ALL ROVER REMS : https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?rover=Curiosity
	* ROVER REMS BY SOL : https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?rover=Curiosity&sol=9
	* ROVER REMS BY SOL RANGE : https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?rover=Curiosity&min_sol=1&max_sol=15
	*/
	function fetch_manifest(){
	var db_msl = ws_msl.getDataRange().getValues();
	var max_sol_msl = db_msl[db_msl.length - 1][2];
	return {'rovers':{'Curiosity':{'max_sol':max_sol_msl,'PARAMETERS':['rover','sol']},
	'Perseverance':{'max_sol':null,'PARAMETERS':['rover','sol']}},
	'sample_calls':{'manifest':'https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?manifest=yes',
	'rover_all_rems':'https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?rover=Curiosity',
	'rover_rems_by_sol':'https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?rover=Curiosity&sol=9',
	'rover_rems_by_sol_range':'https://script.google.com/macros/s/AKfycbwV7SeFLW_LM0NDfZNVHyDYss8Cq7RSGMMnicX3Jo1aGsasaxxbkWzqiR3DAMyHwE8N/exec?rover=Curiosity&min_sol=1&max_sol=15'}};
	}
	/**
	* THIS IS A FUNCTION TO EXTRACT FROM DB THE CORRESPONDING ROVER REMS DATA
	* CALL BY ROVER NAME
	* CALL BY ROVER NAME AND SOL
	* CALL BY SOL RANGE (MIN_SOL AND MAX_SOL)
	*/
	function fetch_rover_data(rover,sol,min_sol,max_sol){
	var db;
	if(rover === 'Curiosity'){
	db = ws_msl.getDataRange().getValues();//GET DATA
	}
	db.shift();//REMOVES HEADER
	return fetch_weather_api_data(db,sol,min_sol,max_sol);//RETURNS DATA
	}
	/**
	* THIS WILL FETCH THE CORRESPONDING REMS DATA
	* EACH ROW IS A SOL WEATHER INFORMATION
	*/
	function fetch_weather_api_data(ws_db,sol,min_sol,max_sol){
	//FETCH BY SOL
	if(sol != null){
	ws_db = ws_db.filter(function(el){
	return Number(el[2]) === Number(sol);
	});
	}
	//FETCH BY SOL RANGE
	if(min_sol != null && max_sol != null){
	ws_db = ws_db.filter(function(el){
	return (Number(el[2]) >= Number(min_sol) && Number(el[2]) <= Number(max_sol));
	});
	}
	//ASSEMBLE JSON STRING BY EACH ROW OF REMS WEATHER DATA
	ws_db.map(function(el){
	var row = {
	'id':el[0],
	'terrestrial_date':el[1],
	'sol':el[2],
	'ls':el[3],
	'season':el[4],
	'min_temp':el[5],
	'max_temp':el[6],
	'pressure':el[7],
	'pressure_string':el[8],
	'abs_humidity':el[9],
	'wind_speed':el[10],
	'wind_direction':el[11],
	'atmo_opacity':el[12],
	'sunrise':el[13],
	'sunset':el[14],
	'local_uv_irradiance_index':el[15],
	'min_gts_temp':el[16],
	'max_gts_temp':el[17]
	};
	api_data.push(row);//COMBINES ALL JSON STRING REMS WEATHER DATA
	});
	//API CALL JSON RETURN
	return {'desclaimer':'I do not own the data. You are using the data being pulled from my personal script that logged daily weater data from REMS as published on this url(\'https://mars.nasa.gov/rss/api/?feed=weather&category=msl&feedtype=json\'. There could be mismatch from actual data and delay expected as my custom script is dependent on the original api from NASA. Use at your discretion. As a hobbyist this was for education purpose. Thank you!info@trackingperseverance.com)','data':api_data};
	}

view raw Mars_Weather_API_custom.js hosted with ❤ by GitHub