Part 2- Let's know more about solar system and planets.

Hello! How are you all? Let me give my introduction really quick. I'm Mahesh, an undergraduate student who loves know much about space and sharing my knowledge with others. This is a continuation of Part 1 of my previous post.

Have you ever wondered why Earth is the only planet known to be habitable?

I remember a time in school when my classmates were talking about aliens. I was curious and asked, "What are aliens?" They described them as monsters with big eyes and long bodies, like the ones you see in certain pictures. 

   I was stunned—"Monsters?" I thought. But after listening to them, watching some videos, and reading a few books, I realized that anything living outside our planet is often referred to as an alien. Even if there are species similar to us on other planets, they'd still be considered aliens by our definition.
    

       In our solar system, planets are divided into different zones. Some are close to the Sun and experience extreme heat, while others are so far away that they barely get any sunlight, resulting in very low temperatures. For example, Neptune has a temperature around -220 degrees Celsius, and it takes light four hours to reach Neptune from the Sun. This picture should give you some clarity.

    

From this, we can see that Earth falls within the habitable zone, and so does Mars. You might have heard someone say that people are living on Mars and observing us. If not, let me clarify. Curiosity, a rover launched by NASA on November 26, 2011, was designed to study the Martian surface. During its mission, the Curiosity rover discovered radioactive materials similar to those found in nuclear bomb explosions. This led scientists to speculate that there might have been a time when humans lived on Mars, and due to a nuclear war, the planet became highly radioactive. This hypothesis arose not only because of the radioactivity but also due to evidence of ancient oceans and other signs of past life.

Let me know what you think about this in the comments. I hope you find this an interesting topic to explore. Stay tuned—more parts are coming, and they’re going to be even more fascinating! Thanks for going through this.