FirstLight Astronomy Club

33°29.6'N / 117°06.8'W / 1190 ft.

To Boldly Go?

These last weeks we have celebrated the truly historic events in the history of mankind of not only getting to another heavenly body, specifically the Moon, but actually landing and walking on it. Those of us who were alive then will never forget it. What a blessing it was to be one of the privileged few to observe a genuine milestone in the history of humankind, at the same time believing that our venture into space had finally gone beyond science fiction and was now a reality.

Suddenly the realistic setting (if not premise) of 2001: A Space Odyssey, which came out the same year, didn't seem so far-fetched. Real space stations, real settlements on the Moon, real manned space travel to different planets within our generation was conceivable; it could happen!

But it has not. And in the grand tradition of science, allow me to make a prediction based on the facts: Sadly, it probably won't.

The last 40 years have been a reality check, to be sure. In this last generation we have discovered some things about ourselves and the universe which, I believe, have put a big fat roadblock in the way of our quest "to boldly go where no man has gone before."

One reality check is that elaborate space projects are stifled by politics and time and money and legalities. Just look at the sisyphean International Space Station. That one spacecraft is still being built at immense expense despite over a decade of international teamwork.

And consider our interest in it all. We are a fickle species to be sure. Our interests wax and wane in very short time spans. For example: Many people know the men who went up on Apollo 11. But this week marks the anniversary of the landing of Apollo 15. Name one of the astronauts, or where they landed, or what they accomplished, even the year they went up. After Apollo 11, interest in the Moon crashed. No public interest means little - if any - government support. Lose that and your project is doomed.

Another problem: Today we know a lot more about our solar system than we did back then, and our neighborhood, it seems, is a disk of death. Mercury, Venus, the "gas giants," their moons - most all are off limits for us. They are lethal. But what about Mars?

Space travel to even that closest, "friendliest" planet is a logistics nightmare. Cramming a handful of people into a small capsule for nearly a year just to get there poses profound physiological and psychological problems. Imagine attempting to get beyond our solar system!

The list goes on. Understand that I don't like this. I dreamed of going to the Moon when I was a kid; I still do. I enjoy the interplanetary travel in movies like Star Wars and its genre (providing there's a good plot!). But when we come down to it, it is still science fiction.

To be sure we are meant to move, explore, venture laterally across the surface of our privileged home. But I have a bad feeling that going up, up and away ain't happening.

Still, it would be cool.

And the Winner is...

This week let’s have ourselves a little awards ceremony. We’ll call them The Solies, awards to planets in our solar system which are at the top of a particular category. Ready? 

In a shocking upset, the Solie for Hottest Planet goes not to Mercury, but to its fellow planet farther out, Venus! One would think Mercury to be the clear winner here, being so close to the sun as it is. But Venus has an extra characteristic that little Mercury does not possess. It has an atmosphere - a thick, nasty, carbon dioxide-filled one which can hold onto heat extremely efficiently. Its average temperature at the surface is a warm 900 degrees Fahrenheit. 

As a consolation prize we’ll give Mercury the Solie for Greatest Day/Night Temperature Difference. Mercury has one heckuva long day. One sunrise to the next lasts about 180 of our days! During its “daytime,” its temp sores to 800 degrees Fahrenheit, but when that same surface turns away from the sun and has months to cool down, it does so with a vengeance, cooling to 280 degrees below zero. Overall difference: over 1000 degrees. Congratulations, Mercury!

The Solie for Most Massive Planet goes to... Jupiter! Now this probably comes as no surprise to you; most people would predict Jupiter the winner here. But what you may not know is that Jupiter is made of more mass - more “stuff” - than all the other planets combined! It is a genuine heavyweight. But wait! Isn’t it only just slightly bigger than Saturn? How can it be so much more massive?

Recall that more mass means more gravity. And recall also that gasses can compress. Jupiter has a lot more mass than Saturn and all the rest combined, but its outer gaseous layers are compressed under that greater gravity. That’s one reason why adding more stuff to Jupiter doesn’t allow it to grow appreciably. 

The Solie for Least Dense Planet goes to... Saturn! But how, if it is so huge! Remember that how dense something is isn’t the same as how big something is. How dense an object is tells us how much stuff is crammed into a certain volume. So something can be huge, like Saturn, but not be made of a whole lot of stuff. So it isn’t too dense. 

In fact, Saturn’s average density is less than that of water, but don’t try floating it in a great ocean to see if it will float. It might stay afloat in your imagination, but in real life, too many physical factors prevent this grade school analogy to work.

Our final Solie was a unanimous choice. This planet is not biggest, smallest, closest, farthest, hottest, coldest, or densest - none of those. But one could write books about the myriad subtle characteristics that make this planet the clear winner for being the one most consistently and artistically designed for life. Our Lifetime Achievement Solie goes to our own home: Earth. 

Congratulations, Earth. May all your inhabitants learn to appreciate just how beautiful you are.
Temecula Valley High School / Temecula, CA · Some images © Gemini Observatory/AURA Contact Me