At the bottom of this entry, I give the Weekly Pondering 3 assignment, for those of you in ASTR 1/2. The text that you need to read is linked to below.

Recently, we have learned a bit about the Solar System and the Earth. In studying these topics, it becomes evident that Earth is uniquely habitable within our own Solar System. One of the most famous planetary scientists of the modern era is Carl Sagan, who also wrote and spoke about science to the general public. This week, we will discuss a chapter entitled “Remaking the Planets” from one of Carl Sagan’s most influential books, Pale Blue Dot. (You can read it here.) In this chapter, Carl Sagan considers the current and future habitability of the Solar System. We know of no other object—planet, dwarf planet, asteroid, or comet—that is currently habitable for humans. In the future, however, a desire to explore the Solar System in an increasingly thorough fashion may compel humans to establish permanent colonies on other terrestrial bodies.

We are lucky to live in an era when there are multiple active rovers on Mars. In February 2021, the rover Perseverance, part of NASA’s Mars 2020 mission, landed on Mars. Perseverance is a car-sized, 1000 kg rover that is exploring the past habitability of Mars and looking for biosignatures from life forms that may have existed on Mars in the past. It is also attempting to determine the potential for human exploration of Mars. You can learn more about the mission here:

https://mars.nasa.gov/mars2020/

Read the cited chapter by Carl Sagan, linked to above. In a paragraph or two, discuss some of the most difficult problems that you think will have to be solved to send people temporarily and permanently to Mars. Let’s assume that terraforming is not feasible. We will discuss this during the WP3 session.