Basic Concepts on Solar and Lunar Eclipse!

Here are a few basic concepts about Eclipse:

• When Sun and Moon are close to each other (same house), it's called Amma Vasya (New Moon).
• When Sun and Moon are 180 degrees apart (7th house from each other) , it's called Poornima (Full Moon).
• A solar eclipse occurs only on Amma Vasya and Lunar eclipse takes place only on Poornima and depends on the intersection of Rahu and Ketu.
• If either of Rahu/Ketu is associated with Sun/Moon an eclipse is created.

Lunar Eclipse (27th July 2018):
Sun is in Cancer (Kataga) and Moon has moved to Capricorn (Makara) which is 180 degrees apart. Rahu is posited in Cancer with the Sun and Ketu is right now in Capricorn along with the moon giving rise to a perfect Lunar Eclipse.

Solar Eclipse (11th Aug 2018):
Sun is in Cancer (Kataga) and Moon is also now in Cancer (Kataga) and they are conjunct with each other. Rahu is posited in Cancer along with the Sun & Moon and Ketu is 180 degrees apart in Capricorn giving rise to a perfect Solar Eclipse.

                                                                  Lunar Eclipse

                                                                 Solar Eclipse

Just to get the drift, concentrate only on Sun, Moon, Rahu and Ketu. The Lunar eclipse takes place in the signs of Cancer and Capricorn (Sun & Rahu in Cancer and Moon & Ketu in Capricorn) whereas the Solar eclipse also takes place in the signs of Cancer and Capricorn (Sun, Moon & Rahu in Cancer and Ketu in Capricorn)

Notes:

1) Rahu (Dragon Head) / Ketu (Dragon Tail) are always 180 degrees apart and transits a sign approx every 1 and half years. 

2) Sun transits a sign approx every one month (30 days)

3) Moon transits a sign approx every 2 and a quarter days (54 hours)

Hence, there is always the possibility of a Lunar & Solar eclipse taking place within a short time frame. Moon, who is posited along with Ketu in Capricorn and is directly opposite to Sun & Rahu in Cancer  forming a Lunar Eclipse on 27th July 2018 will quickly traverse to Cancer in roughly another 14-15 days (Approx 2.25 days * 6 signs from Capricorn to Cancer) to join Sun and Rahu and be opposite to Ketu in Capricorn giving way to form a Solar Eclipse on 11th August 2018.