So, let’s cover this topic on following points – 

Let’s deal with all points one after the other. 

What is an Aspect? – So, 1st of all, what is an Aspect? In the most ordinary sense of understanding, understand Aspect as a Sight or Drishti. Just like we all have a Sight and it falls on some place or person, it is considered that planets in sky also have a sight and that sight falls at different places in sky, i.e. houses/signs or on other planets and impacts the human life. It is always better to understand planets as persons then we can understand easily how they work? Just like persons can have friendship/enmity within each other, planets can also have. Likewise, just like we have a sight, planets also have a sight/aspect by which they observe the things around them. This is the most basic understanding of Aspect. 

Percentage of Aspect – Now, this point becomes confusing for many as to how planets have different percentage aspects at different houses? At one house, a planet will have 100% aspect, but at another house it may have 25% aspect. How does it work? Again, the simplest way to understand this, is to treat the planet as a person. So, a person, standing upright, can have his 100% sight going in front, right? Likewise, every planet has 100% aspect on the 7th house from itself as 7th house is right in front. Then, a person, standing upright and without moving his neck, can’t have a look over his shoulders, right? Likewise, a planet can’t have sight over 2nd house and 12th house from its house as they work like shoulders to the planet. Other percentage of aspects of planets also depend on the kind of angle they are making to a particular house from their position. What we will cover here are 100% aspects as they are responsible for triggering events. It doesn’t mean that other aspects from 25% to 75% doesn’t matter but they will depend on other factors of chart for triggering the event. Let’s move further. 

100% aspects of planets – So, following are 100% aspects of planets – 

Benefic Aspect Vs Malefic Aspect – It is important to note if planet aspecting is a naturally benefic planet or malefic planet. A benefic planet (Moon, Venus & Jupiter) will make things easy to the house it is aspecting. A malefic planet (Sun, Rahu, Ketu, Saturn & Mars) will add hard work & struggle to the house it is aspecting. 

Aspect on House Vs Aspect on Planet – Now, this becomes important. If a planet is aspecting a house which is empty then it is not as powerful as a planet aspecting a house which has planet there. It means if there is a planet to receive the aspect and reciprocate it, then it really activates the chart and houses involved in the relevant dashas. Even if there is one side aspect, like Saturn’s10th aspect on Moon where Moon is unable to aspect back to Saturn, then also it is better than a planet aspecting an empty house. But again, it doesn’t mean that planets aspecting empty house has no value. It is just that one side or mutual aspects have more energy exchange then planet aspecting an empty house. 

Joint Aspects in Birth Chart and Transits – Just like 2-3 planets sitting in one house of chart make that house significant for person’s life, likewise 2-3 planets jointly aspecting a house of chart makes that house important in chart. That is also the case in annual transit of planets, that’s why we look at double transit impact of Jupiter & Saturn to understand which house is getting impacted by them, so that events related with that house can be predicted with more conformity. 

Sandhi Aspects – This is one area of aspects which is normally missed by people. It is when planets are not aspecting by their sign/house positions but they are still aspecting due to close proximity of degrees. For ex – Sun is in Aries at 28 degrees and Mars is in Scorpio at 3 degrees. So, Mars is 8 houses/signs away. So, we can say that Sun is not aspecting Mars as Sun aspects only 7th house from itself which becomes Libra in this case. Once Mars is in Scorpio, it is away from Sun’s 7th house aspect. But important thing is that Sun is at 28 degrees, that means it is about to switch to Taurus, from where its 7th house aspect will go to Mars in Scorpio and the difference between degrees of Sun and Mars are only 5 degrees. So, here it makes a case of Sandhi Aspect as although they are in different signs then aspecting wave-length but the degrees are so close that both planets are able to exchange their energy. Same thing is seen as Sandhi Conjunction when for example, Sun is at 28 degrees of Aries and Saturn is at 4 degree of Taurus. Although, they are in different signs but degree-wise they are very close. If we remove the line between Aries and Taurus, they are within 6 degrees. This is the way Sandhi Aspect and Sandhi Conjunctions should be seen. Anytime planets are within 10 degrees of each other though in different signs, Sandhi Aspect and Sandhi Conjunctions must be checked. 

Divisional Charts - One thing we must keep in mind while reading any Divisional Chart is that we should not use normal planetary aspects in D Charts. Like, don’t use 7th house, 5th house, 9th house etc aspect for any planet in any position in any house. Reason is simple. Planetary aspect works with D-1 chart as it is the map of sky at the time of your birth. Like, if a baby takes birth right now, he will have Sun in Scorpio and we can easily use 7th house aspect of Sun on the house where Taurus falls. But same Sun will go into a different sign than Scorpio in D-charts. It may be in Capricorn. Now, we can’t say that Sun is aspecting Cancer in a D-chart because in sky it was still at Scorpio, not Capricorn. Hope this is understandable. So, the way out is to use Jaimini Aspects (http://astrosaxena.com/bija) in D-charts.

Activation of Aspect – As always, aspects of any planet will be activated during its MD/AD. Before that, planet’s aspect will be there but it will work in support to the planet which MD/AD is going on. Also, aspects get activated in case of mutual aspects as discussed earlier. 

How I will cover this series? – So, I don’t think it will be possible for me to go through a planet’s position in each house for each ascendant. I am planning to make an article for each planet’s aspect and in that I will cover planet in each house and its aspect on other house. Like, article about Sun’s aspect will include Sun’s aspect on 7th house from its position in every house. Only thing you need to figure out is what house Sun rules in your chart? Please feel free to comment if you have any other better suggestion to cover this series. I will consider. 

Conclusion – So, I think we are all set after this introductory article on Aspects to understand how an aspect of planet can impact our life. Last, but not the least, a planet sitting in a house will always have more impact on house than the planet aspecting the house. It is like you are sitting with a person and someone is looking at you from far. You will be more impacted by person who is sitting right besides you. So, let’s begin understanding aspects from the next article on Sun’s aspect.