The vote seemed nearly inexplicable, even to the New York Times [See Plan to Capture an Asteroid Runs Into Politics]. NASA (the National Aeronautics and Space Administration) wants to capture a small asteroid, less than 10 meters in diameter, and haul it back into an orbit around earth where it can be examined closely, perhaps by astronauts. The original unmanned mission was planned for 2018.
Republican members of the Science Committee of the U.S. House of Representatives voted to kill the idea. It was not part of the bill they passed (the Democrats' bill included the NASA-recommendations). They prefer a focus on lunar landings, followed by a Mars mission. There are always arguments about how to use NASA's large but not limitless budget, so this might seem to be just another argument about priorities.
A deeper look depends on knowing what scientists might find if they do capture an asteroid.
Mining asteroids is a science fiction theme from last century. Today it is approaching reality, with at least one private group looking for a way to do it and make money at it. [See Tech Billionaires Plan Audacious Mission to Mine Asteroids]. While platinum is a more likely target, the group certainly would not turn away a gold asteroid if they found one.
Asteroids are believed to be quite varied in composition. They fall into three classes: carbon rich, stony, and metallic. The assumption is their composition is fairly reflected in meteorites (meteoroids that fall to earth). Metal meteorites are less common than stony and carbon rich ones, but they are not rare (about 6% of the total). The most common metallic meteorites are iron mixed with nickel.
There is a subgroup of meteorites which have a percentage of gold in them. It is likely that there are meteorites and asteroids which consist mostly or entirely of gold. In fact a current theory is that most or all of the gold in the earth's crust came from asteroid or meteorite impacts, since the planet's original gold would have sunk to the core of the planet. [See Huge Asteroids Brought Gold to Infant Earth]
It would be possible to select an asteroid that is mainly of the metallic type (M-type asteroids) by studying the spectra of various candidates. With advanced surveying gold bearing asteroids could be distinguished from the more common iron-nickel ones.
Why is this a political problem for Republican members of Congress? Because many (but not all) in the party now want to return to the Gold Standard for money. Many wealthy Republicans, and even middle-class Republicans, have spent the last decade accumulating investments in gold.
They say that Gold is the only real money (despite there being no Biblical evidence for that). But they suspect that if gold were more common, it would behave like other commodities: it would lose value. Behind their outward confidence in gold, they fear change. They fear the laws of supply and demand and free markets.
Suppose NASA captures a 10 meter cube of gold and got it back to earth safely. How much gold is that? Gold has a density of 19.3 grams per cubic centimeter. There are a lot of cubic centimeters in a 10 meter cube. There are 100 x 100 x 100 cubic centimeters in a cubic meter, and 10 x 10 x 10 cubic meters in a 10 meter cube. That is 1,000,000,000, or 1 billion cubic centimeters.
At a price of $1300 per ounce (gold bugs would say we should measure the value of dollars in gold, not the value of gold in dollars), 19.3 grams of gold, which is 19.3/28.35 or 0.68 ounces, is worth $884.
So the asteroid would be worth $884 billion dollars. Which would not pay for the estimated $2 to $3 billion needed to collect the asteroid.
Still, it would be a lot of gold. And it would mean that for all practical purposes, there is all the gold you want in space.
Only it would not be worth $884 billion, because who would buy it? Especially when even more gold goes whizzing by the earth once in a while, just needing a nudge to capture it?
A gold asteroid of very modest size would cause the value of gold on earth to plummet. This is partly because most gold already mined here is not used for anything, not even jewelry. It is in the hands of speculators, who hope it will go up relative to the U.S. dollar, so that they can buy things they really want, like more handguns, bigger mansions, fancier cars, and the more expensive Senators.
Who exactly voted for the bill [H.R. 2687] that left out the asteroid capture mission? Lamar Smith of Texas, Paul Broun Jr. of Georgia, Larry Bucshon of Indiana, Cynthia Lummis of Wyoming, Steven Palazzo of Missouri, Chris Steward of Utah, Jim Bridenstine of Oklahoma, Mo Brooks of Alabama, Thomas Massie of Kentucky, Kevin Cramer of North Dakota, Ralph Hall of Texas, Randy Hultgren of Illinois, Frank Lucas of Oklahoma, Michael McCaul of Texas, Randy Neugebauer of Texas, Bill Posey of Florida, Dana Rohrabacher of California, David Schweikert of Arizona, James Sensenbrenner Jr. of Wisconsin, Steve Stockman of Texas, and Randy Weber of Texas. Lots of Republicans from Texas on the Science Committee.
And for those of you who love details, here is the Text of H.R. 2687