Planets, stars, and physical “stuff” make up a tiny fraction of the universe. Most of the universe’s mass is instead invisible dark matter, which makes itself known not by luminance, but by its gravitational influence on the cosmos. The motions of galaxies and stars require dark matter to be explained. Yet despite decades of searching and millions of dollars spent, physicists still haven’t been able to track down a dark matter particle. In this segment, physicists Jodi Cooley and Flip Tanedo, and Gizmodo science writer Ryan Mandelbaum talk about how experimentalists and theorists are getting creative in the hunt for dark matter.

Plus: Earlier this year Brazil made headlines and received accolades from ocean conservation advocates for turning 900,000 square kilometers of ocean in its exclusive economic zone into a marine protected area. That’s the good news. But the question remains: Does that 10 percent really need protecting? Natalie Ban, associate professor at the University of Victoria, tells Ira more.

And Tanya Basu, science editor at The Daily Beast, joins Ira to talk about advances in breast cancer research and more science headlines in this week’s News Round-up.