This book consists of five chapters. The first chapter describes Miller-Urey experiment, Oparin and Haldane Theory, Reddi experiment, fossils evidence of life, and RNA World hypothesis. The second chapter describes various biological macromolecules like carbohydrates, proteins, lipids, and nucleic acids. The third chapter planets and their composition. The fourth chapter describes various missions conducting on Mars. The fifth chapter describes life on Europa. ContentsPreface..............................................................................................3Chapter 1: Origin of Life............................................................4-141.1 Mill r-Urey Experiment1.2 Who was Stanley Miller?1.3 Harold Clayton Urey1.4 Oparin and Haldane Theory1.5 Coacervate1.6 Primordial Soup1.7 Reddi Experiment1.8 Lazzaro Spallanzani1.9 Discovery of Microorganisms1.10 Fossil Evidence of Life1.11 RNA World Hypothesis1.12 What is Life?Chapter 2: Biological Macromolecules................................15-352.1 Protein2.2 Primary Structure of Proteins2.3 Secondary Structure of Proteins2.4 Tertiary Structure of Proteins2.5 Carbohydrates2.6 Fatty Acids2.7 Nucleic Acids2.8 WaterChapter 3: Planets....................................................................36-436.1 PlanetsChapter 4: Life on Mars...........................................................44-608.2 Meteorite8.3 Various Missions on MarsChapter 5: Life on Europa........................................................61-63References