Query: When did Spielberg announce what would become 'Interstellar'?
Context: In June 2006, Steven Spielberg announced he would direct a scientifically accurate film about "a group of explorers who travel through a worm hole and into another dimension", from a treatment by Kip Thorne and producer Lynda Obst. In January 2007, screenwriter Jonathan Nolan met with them to discuss adapting Obst and Thorne's treatment into a narrative screenplay.