Monthly Archives: August 2016

astronomy, meteors, Perseids

The Perseids are a Part of Solar System History

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Did You Watch the Perseids?

The Perseids from the VLT
A view of a Perseid meteor from the Very Large Telescope array. Courtesy ESO.

This past week the Perseids meteor shower came to its peak. Of course, social media came alive with hints of a huge shower. People followed up by posting pictures of meteors from their observing sites. It’s an annual event, and most people had clear skies for it. We got a chance to see a few Perseids starting a week or so before the peak, but the actual night, it was cloudy at our place. Some years we get the bear, some years the bear gets us.

The bigger story about the Perseids isn’t what you got to see, although it’s pretty neat to watch these bits of space debris flash into oblivion as they enter Earth’s atmosphere. It’s really about what these things represent. And that is a whole lot of ancient solar system history.

The Ancient Source of the Perseids

The Perseids shower is made up of countless particles of dust that stream off of Comet Swift-Tuttle as it passes around the Sun every 133 years. Earth’s orbit intersects that stream beginning in late July through part of August each year. The peak coincides when we’re passing through the thickest part of the stream. That means we see more meteors that night.

Comet Swift-Tuttle originated early in the solar system’s history and is made of ices and dust that existed back when the Sun and planets were beginning to form. That means its materials pre-date the birth of the Sun. As the system formed and evolved, the planets did their dynamical dance to their current orbits, and in the process, sent chunks of ice out to the outer solar system. From there, those chunks got gravitational nudges that eventually sent them on long orbits around the Sun. Swift-Tuttle is one of those chunks.

So, when you see a Perseid meteor — or any meteor for that matter — flash across the sky, you’re watching a piece of solar system history vaporize before your eyes. Occasionally a chunk is large enough to reach the ground and become a meteorite. Anyone who finds it is holding a piece of cosmic history in their hands. Think about THAT the next time you see a meteor flare in fiery death overhead.

Mars

Living and Working on Mars: What Will it Be Like?

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Future Mars and Martians

Mars explorers in a harsh, familiar, and challenging environment. Courtesy NASA.
Mars explorers in a harsh, familiar, and challenging environment. Courtesy NASA.

I’m working on a project that requires me to think hard (and write about) what future colonies and research stations on Mars might be like. There’s no question that people will be heading to the Red Planet within the next decade or so. Humans have been fascinated with the place for millennia. but the details of the first missions are still pretty much in discussion. I’m not too concerned with those, although I do hope they happen soon. I’d love to see what happens to humanity when the first people set foot on Mars. It isn’t going to be a quick jaunt (as I wrote in my now-famous and still-popular fulldome show MarsQuest).

What I’m more interested in now is the second generation or even the third generation of Mars settlers. What will they be like? Will they be moms and dads with kids? Where will they live? What populations from Earth will they represent?  What will their cities be like? Will they have money? Universities? Companies? Pets? What will Martian children be like? There are so many unknowns, which is understandable since we’re talking about the future here.

Living on Mars

The technical aspects are actually pretty straightforward. Figuring out where to live will be guided by conditions on the Red Planet. The UV radiation alone will force people to live underground or in well-shielded structures. Where do the materials come from for those structures? Will the first Martian cities rise above the surface, or extend below it?

Imagine Mars explorers landing here on the Red Planet, using Mars maps with crater names that people of Earth have provided. Courtesy NASA/JPL-Caltech. Click to enlarge.
Imagine Mars explorers landing here on the Red Planet, using Mars maps with crater names that people of Earth have provided. Courtesy NASA/JPL-Caltech. Click to enlarge.

I also wonder what the Martian Gross National Product will be? At first, it will simply be knowledge. After a while, though, there will have to be some other trade relations with Earth, as Mars becomes self-sufficient. I suspect that the planet and its inhabitants will have to learn to stand on their own very quickly since help is months away (at the fastest). The people will need to be resilient in the face of a non-Earth-like habitat. Their children will be unlike any humans born before them — and, I suspect that successive generations of Martians will have different DNA from the rest of us.

It’s an interesting thought experiment, trying to imagine what the Martians 50 years or 100 years from now will be like. I suspect the whole scenario will play out similar to some science fiction books (such as Kim Stanley Robinson’s Mars series), but with distinctly different outcomes based on whatever and whoever it is we are at the time those missions are set up.  Someday, however, I’d like to think that Martian parents will take the kids out for some stargazing, and maybe see Old Earth from the observatory. What stories will they tell the kids?