What planet is hard to observe because it is covered in clouds?

Venus is the planet that is hard to observe because it is covered in thick clouds of sulfuric acid. These clouds reflect a significant amount of sunlight, making Venus one of the brightest objects in the night sky, but they obscure any direct observation of the planet's surface. The dense atmosphere also creates a greenhouse effect, leading to extremely high temperatures on the planet. Consequently, studying Venus requires specialized instruments that can penetrate its cloud cover.