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About a dozen years ago, the notion of bringing a pristine asteroid sample back to Earth was one of those "wouldn't it be cool if..." things nerdy scientists kicked around over a few beers. But after one of those bar-table discussions Dante Lauretta and a few of his colleagues decided they might just be onto something. So they spent seven years writing and making proposals, and finally won enough support from their colleagues that NASA agreed to fund the concept.

The idea has since become a spacecraft, OSIRIS-REx, now resting in a hangar at Kennedy Space Center. The rocket that will launch it into deep space on Sept. 8 stands nearby. If all goes well for OSIRIS-REx over the next two years, it will fall into orbit around the 500-meter asteroid Bennu, and spend the next 700 days carefully studying the asteroid to determine where best to try to grab a sample for a return to Earth.

Only then, sometime in July, 2020, will the real challenge begin. How, exactly, does one reach out and grab some pebbles off the surface of an asteroid and live to tell the tale? Ars spoke with Lauretta, a planetary scientist at the University of Arizona and the mission's principal investigator, to get the details.

(credit: Gage Skidmore)

Donald Trump's controversial luxury golf resort in Aberdeenshire has a chequered history of putting its neighbours' noses out of joint, but this time, it's flouted the UK's data laws by failing—possibly for years—to register with the Information Commissioner's Office.

The Guardian found that the £30 million resort in north-east Scotland hadn't been registered under the Data Protection Act, "despite operating an extensive CCTV system and handling data on thousands of golfers and guests, its staff, and suppliers," potentially putting Trump's golf resort at risk of being found guilty of a criminal offence and fined.

However, just as the ICO was preparing to write to Trump International Golf Course to remind it of its legal duties, it received registration details, somewhat taking the wind out of the sails of the newspaper's investigation.

(credit: Universal Images Group / Getty Images)

I was kind of shocked and amazed by a recent publication in NanoLetters. It seems that viscosity measurements are still difficult. In my ignorance, I had assumed that this was a solved problem. And, just to show the depths of my ignorance, it turns out that you can learn something about a person's health by measuring the viscosity of their blood. This process is time consuming, as I'll explain in a moment. Now, thanks to the power of our ability to build little gold-iron alloy helices, these measurements just got a whole lot easier.

Stick around and I'll tell you about viscosity

Viscosity is a measure of how well things flow. So, for instance, water flows quite easily and rapidly, while some oils flow more slowly—we say that oil is more viscous than water. The study of fluid flow is a very complicated business so, to simplify the problem, you have to ask yourself what is important. For instance, water flowing down a river is probably dominated by the sheer mass of moving fluid. That means you can probably ignore any influence of viscosity and just worry about mass.

On the other hand, when blood reaches the extremities of the body, it is flowing in very fine channels. There is not a lot of mass to the fluid, but the viscous forces between the channel wall and the fluid are enormous. Here, it might be appropriate to ignore anything to do with mass and focus on viscosity. By examining relationships like this, you can build reasonably accurate models of fluid flows without enduring the pain of the full complexity of fluid dynamics equations. But you can only choose what to include in your models if you know the viscosity reasonably accurately.

(credit: Tom Campbell)

I battled the ants for about a year before I started noticing interesting patterns in their behavior.

My military tactics against the invaders were those of a typical San Francisco eco-nerd. I used non-toxic spray made with orange peels to repel them (it actually works pretty well) and placed low-toxin poison sugar bait traps close to cracks they used to enter the house. But these tiny, brown insects seemed unstoppable. They would swarm onto their targets seemingly out of nowhere. I’d put out my cats’ food and come back in 45 minutes to find a thick, wriggling line of ants moving between a crack in the wall and their kibble target. If I blocked their trail with poison, they'd pour out of a different crack next to the kitchen counter. Or at the base of the stairs. Or in my bathroom.

By necessity, I spent a lot of time watching these tireless insects overcoming every obstacle. And during all that reconnaissance, I started to see things that made me wonder who these ants really were.