Aunque + ind vs subj

Question

This article is extremely confusing. One of your examples is   Voy a salir aunque llueva and you use the subjunctive in the next example—llueve but your translation is the same!?  Aunque + subjunctive seems like it should be translated as even if, implying either they don’t know if it is raining or they are talking about a time in the future.  Aunque + indicative translates as even though and implies a known fact.  I am going out in spite of knowing that it is raining. The talk about shared or background information is something I have never heard before

Accepted Answer

Hola Andrew
I looked in the lesson and checked the translations but we do have different translations for each case: 
First we talk about information that the speaker considers as something new for the listener, something they are declaring (aunque + present indicative)

Voy a salir aunque llueve mucho.
I am going out despite the rain.

We use "despite" here.
Then we continue with another example where the speaker is using the present subjunctive  indicating that the fact that is raining is somehow known by them - they're just stating the obvious (aunque + present subj):

Voy a salir aunque llueva mucho.
I am going out although it is raining.

We are using "although" here which could easily indicate this known information.  Using "even though" here would of course convey the same, but although is also an option.
And finally we have another example to illustrate that that information can be taken as something that may happen in the future but we don't know for sure (aunque + present subj) - in this example we add the word "después" to reinforce the future:

Voy a salir después aunque llueva mucho.
I am going out later even if it rains.

Here we are using "even if" to convey the "possibility of raining" as opposed to the certainty. 
I hope this clarified it.
Saludos
Inma