Retrograde periods for Mercury, Venus, Mars, Jupiter and Saturn. Rahu and Ketu are always retrograde by convention.
3 retrograde periods in 1973
23 days in Kumbha
24 days in Karka
20 days in Tula
1 retrograde period in 1973
121 days in Makara
1 retrograde period in 1973
67 days in Mesha
Rahu and Ketu are the lunar nodes and are always Vakri (retrograde). They move backwards through the zodiac at roughly 1.5° per month and change Rashi only once every ~18 months.
