Life on Frozen Moons

picture of Harry KellerBy Harry Keller
Editor, Science Education

Now that three of the moons of our solar system’s gas giant planets have been said to have subsurface oceans, it’s time to take stock and consider the meaning of these analyses.

Ganymede and Europa of Jupiter along with Enceladus of Saturn are likely to have oceans far below their frozen surfaces. Should we send unmanned missions to explore these unusual moons, and what should we be searching for? Many have exclaimed that we have extremophiles (organisms that survive in extreme environments) here on Earth, so we cannot discount the likelihood of life beneath miles of ice where the Sun never shines.

This image or video was catalogued by Jet Propulsion Laboratory of the United States National Aeronautics and Space Administration (NASA)

Enceladus’ north polar region. This image was catalogued by NASA’s Jet Propulsion Laboratory.

If we search near the geysers of Enceladus, might we find the frozen remnants of miniature fish coughed up from deep down inside this odd moon? Answering this question requires more than a moment’s thought. What is life? How does it begin and advance? Are the ingredients for life available in those cold, deep seas?

Here’s my definition. Life uses available energy and materials to reproduce itself and has the potential for errors in reproduction that will allow for evolution. From what we know, those vast, cold underground oceans have the necessary ingredients. Without an energy source, they would be frozen and not liquid. Heat coming from the inside of a moon must provide chemicals that can both be used as chemical energy sources and as materials for constructing living organisms.  Continue reading

Does SETI Make Sense? Part IV: Communicating

Harry SETI header

We are likely to be the only civilization in our galactic cluster if the chances of forming such a civilization are but one in ten trillion. These are not encouraging numbers. For the sake of argument put the odds up to having 100 civilizations in our galaxy. That’s lots more than I would expect and means that the estimates are way off, by a factor of 10,000. Such an improvement in estimates certainly is friendly to SETI. But, can we contact one of these other civilizations?

Although I think that SETI is a colossal waste of resources, I cannot fault those who pursue this dream.

The galaxy is a very large place, about 100,000 light-years across. Any civilizations will be in an annulus around the center because being close to a galactic center is inimical to life. We won’t be able to communicate to the other side of our galaxy due to the extreme noise originating at our galactic center. Our potential range for communication is probably about 20,000 light-years, but this range again is limited by the number of noisy objects between us and our target.  Continue reading

Does SETI Make Sense? Part III: Evolution

Harry SETI header

Every planet that develops life based on chemistry similar to ours will begin with single cells. The entire water ecosystem will consist of these cells in some variety. That variety necessarily came about due to errors in copying the cells from one generation to the next. They would have a rather mundane life of drifting about randomly until encountering some useful molecule and absorbing that molecule. When enough of these molecules had been absorbed, possibly taking years, the single cell will divide into two.

In this slow, inexorable process, the seas will become full of these cells. Some will drift to inhospitable places where they’ll be killed and spill their contents back into the sea for other cells to absorb. Direct conflict is unlikely because the apparatus for killing and absorbing other cells is too complex to develop readily.

Altogether, there’s something like a chance in a billion that a given star will have a planet that can develop and sustain life. The chances are probably much worse.

Early on, after about a billion years, some developed the ability to use sunlight to make molecules from CO2 and water, from chlorophyll, probably an early form that has evolved into its many varieties today. Some scientists suggest that the earliest versions of chlorophyll did not produce oxygen as a byproduct. By about 2.3 billion years ago, some definitely had and started putting oxygen into the water. For life at that time, oxygen was a serious poison, worse than cyanide is to us. It was a matter of adapt or die — or hide somewhere where oxygen did not exist.

This was probably the first great extinction on Earth, and it was caused by oxygen pollution. Evolution favored those who had a way to neutralize this nasty chemical. Slowly but surely, the removal of so many anaerobic species left ecological niches open, and aerobic cells began to fill them. They used a new way to create energy though oxidation, a much more efficient way than their predecessors. Unfortunately (or fortunately from our viewpoint), the oxygen had some other side effects.

Continue reading

Preparing Your Child for a Robotic Future

Don’t Let a Robot Take Your Child’s Future Career: Roboticist’s Book Offers Educational Advice for Parents

Illah NourbakhshIllah Nourbakhsh says robots and artificial intelligence will increasingly displace people from many conventional jobs. The professor of robotics at Carnegie Mellon University has even written a book about it, called “Robot Futures.”
It’s enough to make parents despair over their children’s career prospects, he acknowledged, and that’s why he’s publishing a pair of follow-up books, “Parenting for Robot Futures.” Part 1: Education and Technology is now available on

The key, he said, is to raise children who are “technologically fluent.”

“If we want our children to flourish in a technology-rich future, we need them to understand technology deeply— so deeply that our kids influence the future of technology rather than simply being techno-consumers, along for the ride,” he writes.

“There are no shortcuts to developing tech fluency, and there is no way to outsource the parent’s role to school, after-school or video games,” Nourbakhsh writes.

In the 64-page first volume, Nourbakhsh provides an overview to help parents understand the strengths and shortcomings of technology education in schools, including the movement to STEM (science, technology, engineering and mathematics) education, digital learning and massive open online courses, or MOOCs.

Continue reading

Does SETI Make Sense? Part II: Life

Harry SETI header

The question of what is life has puzzled us for centuries. A new movie, Chappie, addresses this issue in the context of what is a spirit or a soul. Life is simpler but still can be awkward. Because we’re seeking to find civilizations that send out radio waves, we can limit our ideas of life somewhat. Life could be defined as something that reproduces itself using available energy and material resources. To be useful, this life should also be capable of making reproductive mistakes that lead the way to evolution. Without evolution, that civilization could not appear.

In order to figure out if SETI makes sense, we must gather some sort of estimates of the probability of life starting and of it evolving into something like us. We must also determine how many stars harbor planets capable of supporting such life.

Before beginning this peregrination of thought, consider that our version of life here on Earth consists of organisms spawned in water and built of carbon, oxygen, hydrogen, and nitrogen plus some other elements in smaller proportions. Any life must be capable of a complex chemistry and of building rather extensive molecules. Finally, the basic construction materials should be close at hand and in reasonable abundance.

Hydrogen is the most abundant element in the universe and constitutes nearly all of its normal matter. It is found in important simple compounds: water, ammonia, and methane. These also are the simple compounds in which oxygen, nitrogen, and carbon reside. While some have suggested that alien life chemistry might use silicon in place of carbon, the much greater abundance of carbon argues against that route. Similarly, water is not only abundant on the Earth but also throughout space. It has the advantage of being an excellent solvent and the odd characteristic of expanding upon solidifying so that lakes freeze from the top down. All of these features make water the best medium for harboring life by a large margin.  Continue reading

Does SETI Make Sense? Part I: Numbers

Harry SETI header

Understanding SETI (the Search for Extraterrestrial Intelligence) requires that you become involved in a great many different fields and comprehend some rather difficult concepts. For most, it becomes a matter of faith, just what science is not all about. This series of articles attempts to make sense of it all, to put you in a position of deciding on a rational, not faith, basis whether SETI is worthwhile or a waste of time and money. They also provide the basis for some interesting class discussions. Enjoy.

Carl Sagan

Carl Sagan

Carl Sagan famously was a strong supporter of SETI and even wrote a novel that put the best possible face on it. For many like Sagan, the benefits of simply knowing that other intelligent life exists out there overwhelms the negatives of cost and time. What do you think? Will you have a different opinion when you have finished reading these articles? Read on.

The first problem with addressing SETI and similar issues revolves around the huge numbers involved. They truly are astronomical. For SETI, we have to have an idea of how many planets in the universe may be capable of harboring life. Our galaxy, the Milky Way, has over 100 billion stars, possibly much more. The universe also has over 100 billion galaxies. These are huge numbers indeed, but the total number of stars in the universe is their product, greater than ten sextillion.

The Allen Telescope Array (ATA).

The Allen Telescope Array (ATA).

In case you haven’t heard of a sextillion, it’s a one followed by 21 zeroes. To get an idea of how big that number really is, consider a few examples.  Continue reading

Mars One: 100 Still in Running to Be First Humans on Mars

Amersfoort, 16th February 2015From the initial 202,586 applicants, only 100 hopefuls have been selected to proceed to the next round of the Mars One Astronaut Selection Process. These candidates are one step closer to becoming the first humans on Mars.

“The large cut in candidates is an important step towards finding out who has the right stuff to go to Mars,” said Bas Lansdorp, Co-founder & CEO of Mars One. “These aspiring martians provide the world with a glimpse into who the modern day explorers will be.”

The Mars 100 Round Three candidates were selected from a pool of 660 candidates after participating in personal online interviews with Norbert Kraft, M.D., Chief Medical Officer. During the interviews the candidates had a chance to show their understanding of the risks involved, team spirit and their motivation to be part of this life changing expedition.

Dr. Norbert Kraft said, “We were impressed with how many strong candidates participated in the interview round, which made it a very difficult selection.”

There are 50 men and 50 women who successfully passed the second round. The candidates come from all around the world, namely 39 from the Americas, 31 from Europe, 16 from Asia, 7 from Africa, and 7 from Oceania. The complete list of Mars One Round Three Candidates. Statistics on the candidates can be found here.

The following selection rounds will focus on composing teams that can endure all the hardships of a permanent settlement on Mars. The candidates will receive their first shot at training in the copy of the Mars Outpost on Earth and will demonstrate their suitability to perform well in a team. More information about the selection process can be found here: Mars One Selection ProcessContinue reading