Geoff Brumfiel

As investigators learn more about what happened to a Ukrainian International Airlines flight which crashed in Tehran, a growing body of online evidence suggests it was shot out of the sky.

Video footage and the locations of key Iranian military facilities lend credence to the idea that the jetliner carrying 176 people was accidentally shot down.

How much time might it take for Iran to develop a nuclear weapon and a delivery system to launch it? Here are some scenarios for what could happen.

At least five structures were damaged in the attack on the base in Anbar province, which apparently was precise enough to hit individual buildings. There have been no reports of casualties.

Iran attacked military bases used by U.S. and coalition forces in Iraq with ballistic missiles. Over the past 20 years, Iran has built up a powerful force that is difficult to defend against.

The Iraqi Parliament has passed a resolution calling for the expulsion of U.S. troops from Iraq, while the U.S.-led coalition fighting ISIS has announced a pause in its operations.

The star Betelgeuse has been dimming rapidly in recent weeks, leading to speculation that it may soon explode. If it did, that event would be a sight to behold.

With the holiday just days away and no sign of a diplomatic breakthrough in sight, here are what experts say are the possibilities for North Korea's "Christmas gift."

The comet, 2I/Borisov, looks surprisingly like comets closer to home. It's a sign that the processes that formed the sun and planets are at work elsewhere in the universe.

Everyone knows about Apollo 11, the first moon landing. And about ill-fated Apollo 13. Between them is the forgotten mission — Apollo 12.

On this date in 1969, Apollo 12 landed on the surface of the moon. But it seems this moon mission is overshadowed by the more famous Apollo 11 and Apollo 13 landings. But why?

Satellite images shared exclusively with NPR show North Korean fighters and helicopters massed at a single airbase. It could be another sign of escalating tensions.

SpaceX and a rival company are rushing ahead with plans for constellations of thousands of satellites, but regulators might not be ready.

Iran is reopening one of its most controversial uranium enrichment facilities. The move increases its ability to generate enriched uranium and puts more pressure on the already strained nuclear deal.

On YouTube, campaign ads have begun appearing on Russian propaganda channels. But it may be the algorithm, not collusion.

Some familiar political advertisements end up alongside Russian government-backed messaging online. But it's not Moscow's doing. It's about Google — and you.

Three researchers were awarded the Nobel Prize in Physics for discoveries that illuminate our place in the Universe.

A Canadian and two Swiss scientists on Tuesday won the Nobel Prize in Physics for contributions to our understanding of the evolution of the universe and Earth's position in the cosmos.

On Sept. 14, a Saudi oil processing plant was rocked by a series of explosions. The facility, and another oil field, were attacked from the air. Here's what physical evidence exists about the attacks.

The U.S. and Saudi Arabia claim Iran is behind the attack. Iran denies involvement. Here's what the physical evidence shows.