The Sun did not form outside a rotating interstellar cloud. In fact, it formed within a giant, rotating cloud of gas and dust called a molecular cloud.

Here's how it happened:

1. Interstellar Cloud: The Sun began its life as part of a vast cloud of gas and dust in interstellar space. This cloud was mostly hydrogen and helium, but also contained trace amounts of heavier elements.

2. Gravity and Collapse: Over millions of years, gravity pulled the particles in the cloud closer together. As the cloud contracted, it began to rotate.

3. Protostar Formation: The core of the rotating cloud became increasingly dense and hot. Eventually, the core reached a critical temperature and pressure, triggering nuclear fusion. This marked the birth of the Sun as a protostar.

4. Planetary Disk Formation: The remaining material in the cloud, now orbiting the protostar, formed a disk. This disk eventually gave rise to the planets, moons, and other objects in our solar system.

In summary, the Sun did not form outside a rotating interstellar cloud; it formed within one. The rotation of the cloud played a crucial role in the Sun's formation, as it helped to concentrate the material that eventually became our star.