Photographs of Mercury have come to earth for the first time. The Messenger spacecraft entered Mercury’s orbit on March 17 and has just sent back its first batch of photographs. The very first image received shows a crater near the planet’s southern pole, an area that has never been seen before. Neil deGrasse Tyson is an astrophysicist and Director of the Hayden Planetarium and host of “Star Talk Radio.” He helps explain why these photos are important.