Here’s what we’re reading/watching today:

1) NASA has posted an image of a solar-electric propulsion engine currently in development. The engine, which uses xenon ions, burns blue, and NASA is considering using the engine as part of its asteroid retrieval initiative. The engine is being tested at the Jet Propulsion Laboratory. This image was taken at JPL through a porthole during testing.

NASA has released this image of the solar-electric propulsion thruster currently in development and undergoing tests at JPL. An earlier version of the engine is being used on the Dawn mission to the asteroid belt. (NASA/JPL-Caltech)

(NASA via Mashable)

2) Designs for the United States’ most advanced weapons systems have been compromised. According to a Pentagon report, Chinese hackers gained access to the sensitive information—more than 24 weapons system designs. The Post’s Ellen Nakashima reports that the Defense Science Board, which prepared the report, concluded that the data could severely weaken the United States’ military advantage relative to China. Read through the list of compromised technologies.

3) The mobile-only user is ascendant. That’s according to Bond Art + Science partner Karen McGrane, who writes for the Harvard Business Review that the mobile-only user must be catered to for businesses that wish to reach young, black and Hispanic and low-income adults:

“These numbers are already large enough to require attention — and they’re not going down. With sales of PCs at an all-time low, more and more people will rely on their smartphones and tablets to go online. For this growing population, if your content doesn’t exist on the mobile screen, it doesn’t exist at all. Now’s the time to figure out how to meet their needs.”

4) The Big Think‘s “big idea” for today is “discipline and practice.” The site explores the relationship between academic grading and curiosity among America’s youth. Here is philosopher Slavoj Žižek on the importance of asking the right question:

5) And someone has managed to create a lightsaber — well, sort of. The handheld 3W laser, as shown in a video posted by user “styropyro”, mostly lights things on fire, carving a hole through cardboard (before it’s lit on fire). It also cuts through wood, tape and paper. It’s even shown running a solar-powered toy car.

The user writes that the laser is a 3000mW blue laser that runs on two 18650 lithium ion batteries. “I usually try to refrain from using the term ‘lightsaber’ when referring to my lasers,” writes the video creator, “but there really isn’t much else out there to describe this laser.”

Yeah, so steer clear of doing this:

(TNW via Gizmodo)