The Moon and Life

There are many analogies for the likelihood of life spontaneously arising from the primordial soup of early Earth. Dropping Scrabble letters onto the floor and having them arrange themselves into a Shakespearean play. A hurricane passing through a junkyard and leaving a fully assembled 747 in its wake. All things to try and express how unlikely our DNA actually is.

However, there is something that stacked the odds in the Earth's favor - the Moon. But how could the Moon affect the development of life on Earth?

We see the effects of lunar gravity today in the form of tides. Today the tides are relatively tame and usually aren't very destructive. However we can see today that the Moon is slowly spinning away from us. As it orbits around the Earth, the Moon moves ever so slightly away every year.

If you think of gravity like a rope tying the two bodies together as they move through space, the Earth would slowly be letting loose more rope. It isn't fast enough to make any difference on a human timescale. But in the billions of years that the Earth and Moon have been doing their celestial dance, the difference has been quite large.

Just as it is moving further away today, in the past the Moon must have been much closer. Since the Moon was closer, its gravity was stronger, and so the tides would've been much larger.

What difference does that make though?

The tides behaved like a blender, mixing up the primordial soup in the early Earth. The tides would raise and flow over an outcrop, and when the tides recede there will be pools left over. When these pools evaporate, the concentration of the various chemicals and molecules in the water increases. Repeated countless times, over thousands and millions of years.

Each time one of these pools form, it is like dropping a bag of Scrabble letters. If you do it long enough, you'll get Hamlet. Could life develop without a Moon to mix things up? Probably.

Would it have taken much longer? Most definitely. So next time you look up at the Moon, think about how something so far away is directly responsible for the fact that you're standing there looking at it.

The Steam from a Boiling Pot

I have mentioned previously on my blog that most of what astronomers 'know' are not really facts. In astronomy we have few direct observations, and then assumptions based on them and indirect observations we can make of stars and galaxies.

This is a paper I've written on the subject dealing with some research that I've done. It shows that sometimes even the most obvious, basic assumptions we make can be wrong.

Open publication - Free publishing - More research

Seven Threats in Heaven

As promised, here is Seven Threats in Heaven, an examination of seven of the most challenging obstacles that face humanity in the attempt to colonize space. It discusses factors such as creating artificial gravity (which is required for the human body to function properly in space), ways to protect the colonists from cosmic rays and solar radiation, and how to produce food for a population in space.

It is the first of many Astronomical Intelligence articles, hopefully. The presentation style appeals to me - it is professional enough to sooth my ego while being easy enough that I don't tear my hair out trying to get it to work.

Leave a comment if you'd like to see more of these kinds of articles!

Living in Space

If humanity really does damage the environment of Earth to the point that it is no longer suitable for sustaining us, we will have to find alternative places to live or we'll very predictably die. Most likely this would involve creating underwater/underground cities - self enclosed and self sustaining. But if we managed to completely destroy the Earth, where would we go?

Space is logical. We have put several space stations in orbit, after all. What would you need?

For a substantial population to live for an extend period in space, you'd need:
1. A substantial supply of water, and a way to recycle water that is used.
2. A renewable source of electricity.
3. A way to produce Earth-like gravity for the population.
4. Farming facilities - probably hydroponic farming.
5. Protection from solar/extra-solar radiation.
6. A sealed atmosphere, and a way to filter any contaminants. Farming would provide a way to
7. A way to collect needed materials that you can't produce.

A simplified list certainly - but I plan to go into more detail in the future. Check back later for the Astronomical Intelligence's Guide to Living in Space.

How much do we actually know?

It isn't a question that you see asked much, which is in a way more worrying to me than any wrong assumption people might have. The world isn't a science fiction movie, but for all intents and purposes it doesn't matter. Just because the way black holes are portrayed in movies, and so how most people think about them, is wrong doesn't make a difference at the end of the day.

However I think the title question is something that does matter, and it should be asked more often. How much do we know about the universe?

The truth is, we don't actually -know- much at all. The blog title is more than a coy, arrogant reference to my own perceived level of knowledge. It is also a bit of an in-joke about how much we can say for sure that we know about the world around us.

We can't do experiments on other stars or other worlds (outside our solar system). We can't make the universe repeat itself so we can see if thing happen the same way every time. All we can do is watch and make observations. Then we make assumptions based on those observations.

We look at the spectra of stars, and see it looks very much like spectra from the Sun. They are massive, bright, hot objects. We can tell all of that from looking at stars. So we assume that they are like our sun. But we can't say for sure. We haven't gone up to another star and done tests on it. All we can do is make observations of the stars we can see.

So far, they all appear to behave similar to the sun. But even if we look at billions of stars, or trillions of stars, there is nothing to say that the next one won't be something completely different. It's happened before. What we thought were stars at one point turned out to be distant clusters of thousands of stars, or galaxies, or even Blazars, giant jets of energy released as the 'last gasp' of matter falling into a black hole. They all looked like stars until we started looking harder. With better instruments, better detectors, with better resolution.

We very well could be wrong again.

Astronomical Intelligence Audio - Episode 2

This week on Astronomical Intelligence Audio, I talk about what gives stars their power. More specifically, I talk about fusion and how you actually obtain energy from it. I hope you enjoy and find it informative. If you have any further questions, leave a comment and I'll do my best to answer it.

Terra-forming Mars

This is a personal pet peeve of mine that I'm asked about quite often by my friends and family: So when are we going to build cities on Mars?

It. Will. Never. Work.

Not in the way that people would imagine it to work. For those of you who don't know, terra-forming is the process of making another planet or moon Earth-like. It's something that you see in science fiction quite prominently, and it is often applied to Mars.

Not to go into it too deeply, Mars would seem to be a good candidate for terra-forming because all that is needed is for it to warm up and to increase the atmospheric pressure. Currently the atmosphere on Mars is very thin, and so the air pressure is very low.

If you've ever looked at the instructions on a cake mix or other recipes, you may have noticed separate directions for high altitude areas. This is because the atmosphere is thinner the higher up you go, and so the air pressure is lower. Liquids both expand and boil much faster when there is less pressure.

Your body is 70% water. Think about that for a minute.

So increasing air pressure is a must. It is also so cold on Mars that carbon dioxide can freeze, which forms most of the Martian polar caps. That is too cold for any human habitation, so the planet needs to warm up as well. I've just given an obvious answer to both problems though.

There is a large amount of carbon dioxide locked into the polar caps and in the soil of Mars. Carbon dioxide is a very good greenhouse gas, as you've probably heard from the debate on global warming on Earth. That is what we need to do on Mars - global warming. Increasing the amount of carbon dioxide in the air would increase the atmospheric pressure, and the greenhouse effect would warm up Mars.

If there is one thing humanity knows how to do, it is put carbon dioxide into the atmosphere. So what is the problem?

Mars can't hold onto an atmosphere. It used to have a thick atmosphere, and the conditions were right for water to flow on the surface. We can tell because of various clays we observe in the Martian soil which require there to be water for a substantial period to form. However, these regions are billions of years old.

Mars is much smaller than Earth. It's interior cooled much more rapidly. Think of a chicken nugget. After a short time, a chicken nugget will cool off from being cooked. A chicken breast though, after the same amount of time the center will still be warm. The same is true of planets. It is more complicated than that, but the premise is the same.

The cooling interior means that there is no molten core, like on Earth. We currently believe that the Earth's molten core, or rather the rotation of hot metals in the core are the source of the planet's magnetic field. When Mars cooled, this motion stopped and its magnetic field went away.

Without that magnetic field to deflect high energy particles, the atmosphere of Mars was blasted by the solar wind. This slowly stripped the atmosphere of Mars, and Mars doesn't have enough gravity to hold onto an atmosphere anyway. So the Martian atmosphere disappeared.

If we put a new atmosphere on Mars, the same things will happen again. And Mars will end up exactly like it is now.

So, at least in my opinion and with my understanding of science, any settlements on Mars would have to be enclosed in some way. Avoid the losing battle of trying to stick an atmosphere on Mars.