... Tonight and over the next few days, when Mars is at its closest approach to Earth in nearly 60,000 years, you might get your best view ever of our planetary neighbor. ... Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. ... The Tarantula Nebula is more than 1,000 light-years across - a giant emission nebula within our neighboring galaxy the Large Magellanic Cloud. ... Bright Lights, Dark City...