The names of the days of the week in English (and many other languages) are derived from ancient Roman and Germanic mythology, not the solar system.

Here's a breakdown:

* Sunday: Derived from the Old English "Sunnandæg," meaning "Sun's day"

* Monday: Derived from "Mōnandæg," meaning "Moon's day"

* Tuesday: Derived from "Tīwesdæg," named after the Norse god Týr (equivalent to Mars in Roman mythology)

* Wednesday: Derived from "Wōdnesdæg," named after the Norse god Odin (equivalent to Mercury in Roman mythology)

* Thursday: Derived from "Þunresdæg," named after the Norse god Thor (equivalent to Jupiter in Roman mythology)

* Friday: Derived from "Frīgedæg," named after the Norse goddess Frigg (equivalent to Venus in Roman mythology)

* Saturday: Derived from "Sæternesdæg," named after the Roman god Saturn

While the names are similar to some planets in our solar system, the connection is more rooted in ancient mythology and the association of those deities with specific celestial bodies.