Quad-Cities Popular Astronomy Club: My Alien Vacation Home (Part 1) | Local News
Alan Sheidler People’s Astronomy Club
There has been a lot of hype recently about returning to the moon, exploring nearby asteroids, and colonizing Mars. As an aficionado of astronomy and space travel, I’m all for exploring new worlds.
Since before recorded history, humans have always pushed beyond the boundaries of their local communities and colonized other areas. It is natural that this trend will continue.
But which new world(s) should be the target of space colonization? The moon is the closest planetary body to Earth, so it makes sense to consider colonizing it.
At “only” 248,000 miles, or 384,000 kilometers from our home planet, it only takes a few days to travel to the moon, as we saw during the Apollo missions. But the Moon’s gravity is only one-sixth that of Earth’s and there is no atmosphere.
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The film of the Apollo moonwalkers shows them hopping across the surface of the Moon in their bulky, air-conditioned, pressurized spacesuits. Without these protective space suits, the astronauts would not have lasted more than about a minute before succumbing to the extreme temperatures and vacuum of space.
Obviously, the moon is not a corner of the garden. But what about Mars?
NASA photographs taken from the surface of Mars suggest that conditions there are similar to those in the desert of the southwestern United States. These images, however, do not convey how inclement the Martian environment actually is.
Mars, just over half the size of Earth, has lost most of its atmospheric gases. Atmospheric pressure at the surface is only about 1% of Earth’s barometric pressure at sea level.
Although not a total vacuum like on the surface of the moon, a human without a pressurized space suit would not survive for more than about a minute. Even if the pressure was higher, there is no oxygen to breathe. So Mars is not a garden either.
And the asteroids? Most of them are located in the asteroid belt, between Mars and Jupiter. That means it would take them even longer to get to Mars.
There are a few smaller asteroids that come quite close to Earth and might be faster and easier to hit with current technology. But, since all asteroids are small, they have almost no gravity or atmosphere. In fact, the gravity on the little ones is so weak that if you jump, you might go off into space and not come back. Asteroids would therefore not be a good second home either.
Okay, what about Venus or Mercury? At first glance, Venus might be a good choice. It has a composition similar to Earth and is almost the same size. Plus, its surface gravity is only 10% lower than Earth’s, so walking around Venus would be similar to how we do it here.
But, I’m afraid that’s where the similarities end. Venus’ atmosphere is made up of a thick layer of carbon dioxide and sulfuric acid. The barometric pressure is a crush 100 times greater than Earth’s pressure at sea level. Additionally, high levels of CO2 have led to a runaway greenhouse effect. As a result, the temperature on Venus is 900 degrees Fahrenheit (480 Celsius).
An unprotected human on Venus would be crushed and steamed instantly. I think Venus is out!
We can also forget about Mercury, I’m afraid. Mercury, like the moon, has no atmosphere. Because it’s the innermost planet, its sunlit side roasts under a barrage of solar heat and radiation, while the nighttime side is so cold (near absolute zero) that terrestrial Antarctica would seem balmy in comparison. Mercury is also a bad choice for real estate investment, I’m afraid!
Well, what about the outer planets? Jupiter and Saturn are what we call gas giants. As you can guess from the name, they are made up of a lot of gas and there is no visible surface.
What we see are massive, swirling, cloudy envelopes of hydrogen, helium, ammonia, methane and other toxic gases. There is no vital oxygen and no surface to stand on. There may be a surface several thousand miles below the clouds we see, but the pressures there would be overwhelming.
Due to Jupiter’s large mass, its gravity is more than twice as strong as that on Earth’s surface. So even if you could get there and survive, all you could probably do is roll over. Saturn is similar to Jupiter, neither of which are good candidates for a vacation home.
I won’t go into the details of Uranus and Neptune, but they are called “ice giants”. They have colossal atmospheres of swirling gases like Jupiter and Saturn, but are much farther from the sun and are therefore terribly cold and remote. Neither are good locations for your vacation cabin.
There is another class of planetary bodies that we might consider colonizing: the moons of Jupiter and Saturn. A Saturn moon has similar characteristics to Earth, and I’ll tell you more about it next month.
In the meantime, please note that this month of August offers a perfect opportunity to observe Saturn and its moons, as Saturn will be in opposition on August 14th. This means that it is opposite the Sun in relation to the Earth, which makes it visible to all or most. of the night throughout this month.
When Saturn is in opposition, Saturn watchers have noticed a significant brightening of Saturn’s rings at the time of opposition. This brightening is called “The Opposition Surge” or “The Seeliger Effect”, named after the German astronomer Hugo von Seeliger, who first brought attention to it. Brightening occurs when the many small particles that make up Saturn’s rings are illuminated directly behind the observer.
The Popular Astronomy Club will point its telescopes at Saturn and other celestial objects during our monthly public viewing session on August 20 at Niabi Zoo, beginning at sunset. All members of the public are invited to join us. Let’s hope for clear skies and keep looking up!
For more information, visit popularastronomyclub.org or search “Popular Astronomy Club” on Facebook.