I have learnt this from Dr. Suresh Chandra Mishra. As a student, I humbly acknowledge his teachings. He has covered this in multiple places in his other books – for example in Chapter 17 of Brihat Samhita – pages 282 to 291. The books were in क्लिष्ट Hindi and it was a little difficult for me to understand. It is a travesty since Hindi is supposed to be my mother-tongue, but come to think of it, no one has taught us what “latitude” and “longitude” are called in Hindi/Sanskrit. I learnt it from Dr. Mishra that शर is latitude and क्रांति is longitude.
If two planets are extremely close to each other, in terms of both latitude and longitude around the ecliptic, then they are considered to be at war with each other. This is called planetary war and in Hindi books, it is referred to as ग्रहयुद्ध.
In his treatise on Brihat Samhita, Dr. Mishra has considered graha yudh to be of 4 types, which he has also mentioned in his facebook post:
Apart from this, if the longitude of the two planets is far away, and especially if they are in a different direction, then it is normal conjunction and Dr. Mishra does not consider it to be planetary war. In order to find out the latitude and longitudes of the planets, a reasonable astrology software should be considered. The birthchart application on this site cannot be used for this purpose unfortunately at this time. I am upgrading it to the newer version in order to provide the same.
In the Jagannath Hora application, the longitude and latitude should be considered as above. As you can see, on Nov 13th, 2014, the two planets are extremely close to each other and can be seen in the sky together. They cannot be “seen” since both of them are extremely close to Sun, otherwise it would have been a great spectacle. However, their longitudes are are far apart, about 1.5 degrees. So, they will not touch each other. In the above image, please note that Sun defines the ecliptic, Rahu is always on the ecliptic and other planets move around and also up and down like a wave. Negative values indicate position south of ecliptic and positive values indicate that planets are located north of ecliptic.
In case of grah yudh, the mundane astrology results are indicated as follows:
Planets frequently pass each other and every once in a while, the fast moving planets pass each other and pass Saturn/Jupiter etc. However, the combinations for one of the above is pretty rare.
In Sept 2004, Mars and Jupiter crossed each other with 0° in longitude and 10” in latitude. This was the time when there was news of Ambani family splitting. The split was formally announced in end of June 2005 when Mercury, Venus and Saturn were conjunct. Mercury and Venus were equal in longitude and less than 10” in latitude. Saturn was a little far, but was a part of the overall combination.