Let’ try to understand why Mars gets exalted in Capricorn sign and in Dhanishtha Nakshatra. Let’s see what these energies represent –
Mars - Mars represents our will power, courage, ability to take actions, aggressive nature, anger, our fighting ability, brother, male friends, a boy friend for a girl, a soldier, an athlete and real estate etc.
Dhanishtha Nakshatra - It is a nakshatra related with wealth, luxury and lavish life. It is also a nakshatra related with music. Also, it is a nakshatra of celibacy. Please check this link for more info on Dhanishtha Nakshatra - https://www.astrosaxena.com/Dhannaksh.
Capricorn - As Dhanishtha is part of Capricorn sign, Capricorn and things represented by Capricorn are also important here. Capricorn is the 10th sign of zodiac belt, hence it represents many things related with 10th house of horoscope like Law and Order, Government, Authority, Organisation, Discipline etc. Besides it also represents World outside your home and people, Fear and Anxiety etc. Capricorn is consisted of next 2 and half Nakshatra, i.e. Uttar-Ashadha, Shravana and Dhanishtha. Capricorn is ruled by Saturn and that's why it represents Fear and Anxiety.
Please go through the introductory article - https://www.astrosaxena.com/exdeb .
Reasons behind exaltation of Mars in Capricorn – Basically, Mars represents our ability to take actions and put efforts. Capricorn is the sign of Law & Order. So, the basic reason behind Mars’ exaltation in Capricorn is that this person’s actions and efforts are going to be under the Law and Order. Actions can be of any type. We can take any action as we like. Normally, we talk about Free Will and that we take actions as per our own Free Will. Agreed, but how useful or meaningful is that Free Will which is going to harm others. Even a serial killer can say that he utilized his Free Will and acted as he wanted. That’s great but what is the beneficial result of this person’s actions?
Actions can be dignified or undignified. When Mars is in Capricorn Sign, person is all about taking dignified actions. Mars is normally associated with Soldier or Athlete. So, when Mars is in Capricorn, it shows a Soldier or an Athlete who is not taking the wrong means for victory. For them, methods and goal both are important. As Mars in Capricorn is all about taking right and dignified actions which are beneficial for all, Mars is considered as exalted here.
Reasons behind exaltation of Mars in Dhanishtha – Now, Capricorn is again consisted of 2.5 Nakshatras and Dhanishtha falls in last 6.40 degrees of Capricorn. Dhanishtha is the nakshatra of Wealth, Luxuries and Recognitions in life. It is one of the most rewarding nakshatra. So, the underneath message is that a person’s honest actions must be rewarded by others time to time so that he can continue to take right actions. If a person is taking the most lawful actions but if he sees that other people, who are not honest, are progressing in life then how long he will be able to continue his right actions. So, the main reason behind Mars being exalted in Dhanishtha/Capricorn is that not only the person takes right actions in life but he also gains rewards out of it. Another reason behind Mars being exalted in Dhanishtha is that this is Mars own nakshatra. Mars is the only planet which gets exalted in its own nakshatra.
I didn’t find any perceivable reason why Mars gets exalted at 27 degree of Capricorn. If anyone knows that then please feel free to post in comments for everyone’s benefit.