Solar System Model

• Type: Magical Device, Educational Tool, Astrological Aid
• Owners: Hogwarts School of Witchcraft and Wizardry (used by Sybill Trelawney)
• Maker: Unknown

The Solar System Model is a miniature, magical representation of the solar system. The version seen in Professor Trelawney's Divination classroom in the North Tower is contained within a glass dome. Within the dome, miniature planets orbit a central sun, glowing with their own light. These planets move in real-time to reflect the actual positions of their celestial counterparts. When Harry Potter first observes the model, he notes that the planet Mars is “gleaming particularly brightly”.

The primary function of the Solar System Model is to serve as an aid for Astrology, a branch of Divination. It allows a Seer or student to observe the current alignments, positions, and movements of celestial bodies without the need for a telescope. By studying the model, a wizard or witch can interpret the meaning of these planetary positions, which are believed to influence events on Earth. For example, Professor Trelawney frequently references planetary alignments when making her predictions, such as the positions of Venus or the conjunction of Jupiter and Uranus, indicating she uses such a tool to inform her readings.

The specific origin and creator of the model used at Hogwarts are unknown. One such model has been present in the Divination classroom for many years, used by Sybill Trelawney since she began teaching at the school around 1980. Its enchanted nature suggests it is a complex and skillfully made magical object, designed to operate perpetually without manual adjustment.

The Solar System Model is first introduced in Harry Potter and the Prisoner of Azkaban when Harry Potter, Ron Weasley, and Hermione Granger attend their first Divination lesson. It is one of several magical items that creates the mystical and cluttered atmosphere of Trelawney's classroom. The observation that Mars, the Roman god of war, is glowing brightly can be interpreted as foreshadowing the conflict that arises throughout the school year. Later, in Harry Potter and the Half-Blood Prince, Professor Trelawney's reliance on Astrology is reiterated when she complains to Harry about Firenze the Centaur's different divinatory methods, alluding to her own charting of the planets. This reinforces the purpose of the model as a key tool for her specific brand of Divination.

• In the film adaptations, a large, intricate mechanical model of the solar system, often called an orrery or armillary sphere, is a prominent feature of Albus Dumbledore's office. While Dumbledore's office is described in the books as containing many strange silvery instruments, a specific solar system model is not mentioned as being one of them. The model in the films is a visual addition that adds to the sense of Dumbledore's wisdom and vast knowledge (film).
• The wizarding world's use of Astrology and a Solar System Model shows that they share the same basic astronomical understanding as Muggles, though they apply it to magical purposes.
• The planets in the solar system are named after figures from Roman mythology, a naming convention that fits well within the Harry Potter universe, where many spells have Latin roots.