RE: The transformation (Eng/Esp)

Imaginative take on the pickle prompt. Your opening paragraph has a good hook and lays out the mystery very clearly

We are on a mission to the cloud planet. I am Tela and this is my first time aboard the interstellar spacecraft. I feel scared and excited at the same time. We have been monitoring this strange planet for hundreds of years, and a century ago, something terrible happened. A large gray cloud covered it, but the gray cloud has been dissipating.

I like this brief overview of the plot and setting without getting bogged down in to many technical details.

It's also good that after providing a high-level view, you zoom into the details until the eventual revelation of what's really going:

The brown liquid touched her clothes and penetrated her skin. And we could see how Mali's body transformed into one of them. It was a very fast process; first, her skin turned gray, and then she lost his arms and legs and fell to the ground. She head and trunk melted. A complete change of organs, tissues and cells. And when she was one of them, the sound became a murmur again, and liquid began to ooze out of what was Mali now.

Sounds yucky! This is an entertaining and well crafted story.