Here's why:

* Polarity: Sulfur dioxide is a polar molecule due to the difference in electronegativity between sulfur and oxygen atoms. Water is also a polar molecule. Like dissolves like, so the polar nature of SO2 allows it to interact strongly with water molecules.

* Formation of Sulfurous Acid: When SO2 dissolves in water, it reacts to form sulfurous acid (H2SO3). This reaction is reversible, but the equilibrium lies towards the formation of sulfurous acid.

* Acidic Properties: Sulfurous acid is a weak acid. Its presence contributes to the acidic nature of solutions containing dissolved sulfur dioxide.

Overall, the high solubility of sulfur dioxide in water is due to its polar nature, the formation of sulfurous acid, and the acidic properties of the resulting solution.