The Rahu-Ketu Axis
In Vedic astrology, Kalsarpa Dosha (or Kal Sarp Yog) is described in a birth chart when all seven classical planets, the Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn, fall on one side of the shadow-planet axis formed by Rahu (North Node) and Ketu (South Node). This placement is read as concentrating planetary influence between the two nodes rather than spreading it across the whole chart.