Should We Use Comets and Asteroids to Terraform Mars?

First, I would like to thank all those who watched the Sci Fi Science debut and made it such a smashing success. I was overwhelmed by all the response. I did a web chat last week, and so many people logged on that the server crashed, so I would also like to apologize to those who might have been inconvenienced that day.

Second, I would like to comment about some of the questions that came pouring in after that episode. I certainly can't possibly answer all the questions, but here are a few responses that I have chosen.

Question One: If you terraform Mars, making it into a Garden of Eden, won't this be temporary, since Mars isn't big enough to permanently hold onto an atmosphere.

Answer: You are absolutely correct. Mars is a small planet, and hence it's gravitational field is not strong enough to permanently hold onto a dense atmosphere, but it is sufficient to hold onto an atmosphere for thousands to millions of years, which is enough for us. Once we terraform Mars, there will be enough of an atmosphere to take of all our needs for generations to come.

But it does mean that future generations, thousands of years from now, will have to replenish the atmosphere once again. For our purposes, however, it does not matter.

Question Two: Won't sending comets and asteroids down on Mars cause lots of destruction to the surface?

Answer: In the program, we mentioned that it might be possible to heat up Mars using nuclear power plants, but this would be a very slow, expensive, and perhaps dangerous plan. A much faster plan would be to divert comets and meteors to Mars. We also mentioned that, if you aim the comet or meteor carefully, you can control its orbit. This means you can gently have the comet or meteor enter Mars orbit, and then slowly descend to the surface as the orbit decays. This means that much of the comet or meteor will burn up in the atmosphere and release water vapor. The point here is that we can accurately aim the comet or meteor so that we can minimize surface damage but maximize energy transfer, which is what we need to heat up Mars.

Question Three: What is the time frame for terraforming Mars?

Answer: Not anytime soon. A good guess is that we will have our astronauts on Mars by mid-century (given the set-backs in the current manned missions to space). So the first colonies will be established by later in the 21st century. Terraforming won't begin until many decades after that. So we are talking about mid 22nd century before terraforming can be considered seriously. But as Carl Sagan was fond of pointing out, we should become a two planet species, since it is simply too dangerous to place the future of humanity on just one planet.

Next: How to Deflect Meteors and Comets

3D printing might save your life one day. It's transforming medicine and health care.

What can 3D printing do for medicine? The "sky is the limit," says Northwell Health researcher Dr. Todd Goldstein.

Northwell Health
Sponsored by Northwell Health
  • Medical professionals are currently using 3D printers to create prosthetics and patient-specific organ models that doctors can use to prepare for surgery.
  • Eventually, scientists hope to print patient-specific organs that can be transplanted safely into the human body.
  • Northwell Health, New York State's largest health care provider, is pioneering 3D printing in medicine in three key ways.
Keep reading Show less

Lama Rod Owens – the price of the ticket to freedom

An ordained Lama in a Tibetan Buddhist lineage, Lama Rod grew up a queer, black male within the black Christian church in the American south. Navigating all of these intersecting, evolving identities has led him to a life's work based on compassion for self and others.

Think Again Podcasts
  • "What I'm interested in is deep, systematic change. What I understand now is that real change doesn't happen until change on the inside begins to happen."
  • "Masculinity is not inherently toxic. Patriarchy is toxic. We have to let that energy go so we can stop forcing other people to do emotional labor for us."
Keep reading Show less

For most of history, humans got smarter. That's now reversing.

We were gaining three IQ points per decade for many, many years. Now, that's going backward. Could this explain some of our choices lately?

The Flynn effect appears to be in retrograde. (Credit: Shutterstock/Big Think)

There's a new study out of Norway that indicates our—well, technically, their—IQs are shrinking, to the tune of about seven IQ points per generation.

Keep reading Show less

Lateral thinking: The reason you’ve heard of Nintendo and Marvel

Here's why generalists triumph over specialists in the new era of innovation.

  • Since the explosion of the knowledge economy in the 1990s, generalist inventors have been making larger and more important contributions than specialists.
  • One theory is that the rise of rapid communication technologies allowed the information created by specialists to be rapidly disseminated, meaning generalists can combine information across disciplines to invent something new.
  • Here, David Epstein explains how Nintendo's Game Boy was a case of "lateral thinking with withered technology." He also relays the findings of a fascinating study that found the common factor of success among comic book authors.
Keep reading Show less