Sestak, who made his announcement in a video​ posted to his campaign website, is a Vietnam War veteran who also served in Iraq and Afghanistan Source

NASA scientists say its Curiosity rover discovered high amounts of methane gas on Mars. On Earth, the gas is typically produced by living things. CBS News space consultant Bill Harwood joined CBSN to discuss if this observation could mean there’s life on Mars. Source

The passenger said it was a “nightmare” scenario and she has been suffering from night terrors Source

Rep. Michael McCaul said crippling sanction will force the Iranian government to the negotiating table Source

This week on “Face the Nation,” Margaret Brennan talks to Vice President Mike Pence, Sen. Bernie Sanders, Rep. Adam Smith and Rep. Michael McCaul. Plus, part of Ed O’Keefe’s interview with Kamala Harris. Source

NASA and SpaceX are both readying unmanned missions to the Red Planet, with the goal of putting human-filled boots on the ground Source

Vice President Mike Pence, Sen. Bernie Sanders, Kamala Harris, Rep. Adam Smith, Rep. Michael McCaul, Ed O’Keefe, Salena Zito, and Jamal Simmons appeared on this broadcast of “Face the Nation” Source

These are the candidates who have announced a bid for the presidency in 2020, aiming to deny Trump a second term Source

CBS News Foreign Correspondent Charlie D’Agata reports on US-Iran tensions from the Gulf region. Source

Rep. Adam Smith nevertheless criticized the administration’s strategy, saying officials are deeply divided on how to approach rising tensions with Iran Source