... Opportunity and sister robot Spirit have been probing the red planet since early 2004, finding evidence of ancient water, and sending breathtaking images across the inner Solar System. Dawn of the Planets . ... This month, four of the five naked-eye planets gather along the eastern horizon near dawn. The celestial grouping is seen here just before sunrise on May 5, from a beach near Buenos Aires, Argentina. ... Stars, like bees, swarm around the center of bright globular cluster M15. ...