Here's why:

* High Reflectivity: Venus has a very thick, highly reflective atmosphere made mostly of carbon dioxide and clouds of sulfuric acid. This atmosphere reflects a large amount of sunlight back into space, making it appear very bright.

* Proximity to Earth: Venus is also relatively close to Earth, which contributes to its apparent brightness.

While Jupiter is larger and more massive, Venus's high reflectivity and proximity to Earth make it the brightest planet in our sky.