Cosmic News

There's no such thing as breaking news when it comes to us from space. It's not enough for an event to occur; word of it must then travel to Earth across the vast ocean of the cosmos. The dispatch may move at the speed of light, but the journey can still take hours, years, epochs--turning current events into history long before we ever learn of them. Signals from the Cassini spacecraft, currently studying Saturn's moons, take 84 min. to reach us; the supernova whose cataclysmic birth astronomers observed earlier this year was already fading millions of years ago.

Never was the oddly ex post facto quality of celestial news more surreally on display than on May 25, when the Phoenix spacecraft touched down on Mars, the first landing ever in the Red Planet's polar region. In order to arrive at its destination in one piece, Phoenix had to cap its sleepy 10-month journey with a fiery 7-min. plunge through the atmosphere, during which it opened its parachutes, jettisoned its heat shield, fired its engines and decelerated from a blistering 12,700 m.p.h. (20,400 km/h) to a toe-in-the-dust touchdown speed of a few feet per second. With Mars and Earth currently 171 million miles (275 million km) apart, however, signals from the ship need a full 15 min. 20 sec. to get here, meaning NASA did not confirm the 7-min. plunge until 8 min. after it ended. If the ship had crashed, the stream of incoming data would have been nothing more than an electromagnetic message from the grave.

In the era of TiVo, the nail-biting scene at NASA as controllers watched the descent had a curious familiarity to it. Engineers whooped at every milestone just as football fans cheer every pass in a prerecorded game--even though in both instances they know the end of the tale is already writ.

In Phoenix's case, another tale is just beginning. The ship will soon start to sample the frozen soil of the Martian pole, where a possible abundance of ice indicates a possible abundance of water and could--in theory--mean a little bit of life. If such a discovery is made, that news too will reach us 15 min. later--though odds are, no one will gripe about the wait.