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Category: Space
The Newt-onian Mechanics of Building a Permanent Moon Base
Phil Plait, the creator of the Discover blog Bad Astronomy, is an astronomer, lecturer, and author. He’s written two books, dozens of magazine articles, and 12 bazillion blog articles.
On Wednesday, January 25th, Republican presidential hopeful Newt Gingrich spoke to a crowd of supporters in Florida. In a short speech guaranteed to create a buzz—online, as well as among space enthusiasts—he declared that if elected president, “… by the end of my second term we will have the first permanent base on the moon and it will be American.”
That’s a pretty bold statement. Unfortunately, it’s also impossible.
I’ll note he followed that up with something that is far more likely:
We will have commercial near-Earth activities that include science, tourism, and manufacturing, and are designed to create a robust industry precisely on the model of the development of the airlines in the 1930s, because it is in our interest to acquire so much experience in space that we clearly have a capacity that the Chinese and the Russians will never come anywhere close to matching.
That’s a lovely thought, but while that’s a more realistic goal, it’s likely to happen whether or not Gingrich makes it to the White House.
Private Parts
His second statement is the easiest to discuss, and to dismiss. I agree with the sentiment, but what he’s saying is already well on its way to being reality. We have several private companies vying to create commercial activities in orbit, including tourism and science. SpaceX has successfully launched rockets to orbit several times, and they are planning to do a rendezvous with the space station in the coming months as a demonstration that they can take supplies there. Virgin Galactic has shown it can do sub-orbital flights, and several other companies are on their way to space. Manufacturing is a far more difficult goal, but once a more reliable and cheaper method of getting to orbit is established, it’s an inevitable outcome.
With or without any possible future President Gingrich, private companies in space is already happening.
Good News, Alien Seekers: E.T. Probably Doesn’t Need a Freaky-Big Moon Like Ours
Seth Shostak is Senior Astronomer at the SETI Institute in California, and the host of the weekly radio show and podcast, “Big Picture Science.”
The Moon is a ball of left-over debris from a cosmic collision that took place more than four billion years ago. A Mars-sized asteroid—one of the countless planetesimals that were frantically churning our solar system into existence—hit the infant Earth, bequeathing it a very large, natural satellite.
OK, that’s a bit of modestly engaging astrophysics. But some scientists think there’s a biological angle here. Namely, that elaborate terrestrial life might never have appeared if that asteroid had arrived a few hours earlier, and sailed silently by. Put another way, if every night were moonless, you wouldn’t be around to notice the lack of a moon.
But is that true? Did our cratered companion really make our existence possible?
The Ultimate Measure of a Planet—Habitability Isn’t a Yes/No Question
Seth Shostak is Senior Astronomer at the SETI Institute in California, and the host of the weekly radio show and podcast, “Big Picture Science.”
Back in the early days of “Star Trek,” whenever the Enterprise would chance upon a novel planet, we’d hear a quick analysis from Science Officer Spock. Frequently he would opine, “It’s an M-class planet, Captain.” That was the tip-off that this world was not only suited for life, but undoubtedly housed some intelligent beings eager for a meet-and-greet with the Enterprise crew.
But what is an “M-class planet” (also referred to as “class M”)? Clearly, it referred to a world on which intelligent life could thrive, and made it easy for the crew (and viewers) to see where the episode was headed. A recent paper by Washington State University astrobiologist Dirk Schulze-Makuch and his colleagues has suggested a somewhat similar way to categorize real-world orbs that might be home to cosmic confreres. Rather than giving planets a Spockian alphabetic designation, Schulze-Makuch prefers a less obscure, and more precise, numerical specification: a value between 0 and 1. A world that scores a 1 is identical to Earth in those attributes thought necessary for life. A score of 0 means that it’s a planet only an astronomer could love—likely to be as sterile as an autoclaved mule.
Schulze-Makuch computes this index—which he calls an Earth Similarity Index, or ESI—by considering both the composition of a planet (is it rocky and roughly the size of Earth?) and some crude measures of how salubrious the surface might be (does it have a thick atmosphere, and are temperatures above freezing and below boiling?) He combines parameters that define these characteristics in a series of multiplicative terms that are reminiscent of the well-known Drake equation, used to estimate the number of technologically adept civilizations in the Milky Way.
At present the number of worlds thought to have an ESI of 0.8 or greater—near-cousins of Earth—is only one: Gliese 581g (though that planet’s existence is disputed). But as additional data from NASA’s Kepler mission continue to stream in, we can expect that more such “habitable” planets will turn up. In particular, Kepler scientists reported this week on a newsworthy object called Kepler-22b. This planet is 2.4 times Earth’s diameter and in an orbit around a Sun-like star that places it securely in the habitable zone—where temperatures might be similar to a summer day in San Francisco.
Let’s Do Launch: How NASA & Private Space Cos. Can Tame the Final Frontier Together
In the late 1500s, merchants in England sought to ply the waters around Africa in an attempt to set up trade relation s with India. In a few years several trips were made, and, on literally the last day of the 16th century, they were granted a charter by the Queen to incorporate, given free rein to trade with the East.
This was not done in a vacuum, however. For well over a century European explorers had been laying the groundwork (OK, seawork) for this effort. Sponsored by their various governments, they explored the oceans and improved the technology and techniques needed for this to get done. At the time, this would’ve been impossible for private companies—too risky, and too expensive—so governments did the job. National pride was at stake, as well as military and trade advantages.
Like sea travel, space travel is not done in a vacuum—except in the literal sense. Like terrestrial exploration centuries ago, it’s expensive, difficult, technologically cutting-edge, and dangerous. For a young company, or even an established one, a single mistake could cost them a vast portion of their revenue, bankrupting them. In the video below [starting at 14:50], astronomer and space advocate Neil deGrasse Tyson makes this case. It’s something I’ve argued many times as well.
Nevermind Where. *When* Are the Intelligent Aliens?
Only a few decades back, there were serious scientists who thought that planets might be miraculous. Not miracles like a burning bush or a docile teenager, but highly improbable objects. These researchers figured that the conditions necessary for making small, cold worlds could be rare—perhaps extremely rare. Most stars were believed to live their luminous lives alone, bereft of planetary accompaniment.
Well, those thoughts have been banished. In the last 15 years, hard-working astronomers have found many hundreds of so-called exoplanets around nearby stars, and NASA’s Kepler telescope is set to uncover thousands more. (If you don’t know this already, you’ve probably reached this site by mistake. But you’ve come this far already, so keep reading.) Kepler’s principal task is to find habitable exoplanets—worlds with solid surfaces at the right distance from their host star to sport temperatures amenable to the presence of watery oceans and protective atmospheres—planets that might be very much like Earth (depending on some other factors that are harder to measure from light-years away, like geology and chemistry).
Kepler has already found about five dozen candidate objects that, while somewhat larger than our own, seem to meet these criteria. As this space-based telescope continues to peer into the heavens, more such planets will emerge from the data. Indeed, it seems a good bet to guess that at least a few percent of all stars are blessed with “habitable” worlds. That would tally to billions of life-friendly sites, just in our galaxy. This has already prompted SETI scientists to swing their antennas in the directions Kepler’s most promising candidate planets, hoping to pick up the ABCs and MTVs of alien worlds. After all, these systems are arguably the best targets that SETI (the Search for Extraterrestrial Intelligence) has ever had. It’s like discovering a prolific fishing hole.
But there’s a fly in the ointment: While eavesdropping on a small bunch of star systems known to have terrestrial-style worlds is better than taking your chances with random targets, it’s not actually that much better. The reason is simple. The oldest confirmed fossils on Earth are about 3.5 billion years old, and there’s indirect, if sketchy, evidence for life going back 4 billion years. That’s roughly 90 percent of the age of the Earth, which is to say that biology bedecked our planet very early. Life seems to have been an easy chemistry experiment. So that’s yet more encouragement, as it hints that many of those habitable worlds will actually be inhabited. There could be life on billions of planets in the Milky Way.
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