I am a desert known for its extreme aridity and otherworldly landscapes. I am rich in nitrates and other mineral deposits, making parts of me resemble a lunar surface. Though harsh, certain hardy flora and fauna have adapted to survive within me, and I also host some of the world's largest astronomical observatories. What desert am I?

1. I am located in South America.
2. I am considered one of the driest places on Earth.
3. I am a significant source of sodium nitrate.
4. The Very Large Telescope (VLT) is located within me.