For once, hearing little from North Korea could be a bad thing. While the country’s state-run news agency said it had “diversified” its nuclear arsenal with its latest test, it’s unclear if that was a hint that it’s developed a uranium-based bomb. North Korea has only a few dozen pounds of plutonium, which was used in the last two tests, but it has an ample supply of natural uranium. The Washington Post reports that few radioactive traces were detected in the atmosphere following to the blast, raising fears that North Korea is purposely trying to hide what kind of weapon it detonated. Some experts noted that it’s often difficult to find evidence of a nuclear blast, while others said it could mean North Korea is getting help with its nuclear program from Iran. Let’s hope the weather just wasn’t cooperating that day.