Ketu is the Moon's south node, a shadow planet with no body of its own. It stands for letting go, the past, sudden endings and the turn inward. It moves backward through the zodiac, and Rahu always sits in the opposite sign, reaching for what Ketu releases. Cancer is a movable water sign ruled by the Moon. The Moon is an enemy to Ketu in the tradition, so the planet is uneasy here: a planet of release in the sign of home, family and feeling safe.
With Rahu in Capricorn, status, structure and the reach of the state are what the world is reaching for. On the Ketu side, home and belonging come loose. People leave the places they were born in, or lose them. The lesson is that home is something carried as well as something kept.