If the Viking missions were such a rich source of information about Mars, why have we sent the Pathfinder, Global Surveyor, and other more recent spacecraft to Mars? Make a list of questions about Mars that still puzzle astronomers.

The Viking missions, which took place in the 1970s, indeed provided a wealth of information about Mars. However, our technology and understanding of Mars have significantly advanced since then, prompting further missions such as the Pathfinder and Global Surveyor. Here are some reasons why we have sent more recent spacecraft to Mars:

1. Improved Technology: Modern spacecraft are equipped with more advanced technology, allowing for more detailed and accurate data collection.

2. Unanswered Questions: Despite the information gathered from the Viking missions, there are still many unanswered questions about Mars.

3. Search for Life: One of the primary goals of these missions is to search for signs of past or present life on Mars.

4. Preparation for Human Exploration: These missions help us understand the Martian environment better, which is crucial for future human exploration.

5. Study of Mars' Climate and Geology: Understanding the climate and geological history of Mars can provide insights into Earth's past and future.

Here are some questions about Mars that still puzzle astronomers:

1. Does Mars have, or has it ever had, life?
2. What is the history of water on Mars?
3. How has Mars' climate changed over time?
4. What is the composition of Mars' surface and what can it tell us about the planet's history?
5. Can Mars support human life in the future?
6. What causes Mars' dust storms and how do they affect the planet's climate?
7. What is the structure and composition of Mars' core?
8. How does Mars' thin atmosphere affect the planet's surface and potential for life?