Impeachment Questions Answered; Space Debris Could Collide Above Pittsburgh

Now that the impeachment trial of President Trump has moved to the Senate, questions have been raised by our listeners. NPR's Ron Elving answers questions about the process and potential outcome. Also, an old NASA space telescope and a retired Air Force satellite will pass each other 600 miles above earth on Wednesday night. We ask an expert about the odds of a collision and the danger of space debris.