The Planetary Society, an organization that promotes space exploration, has teamed up with NASA to send a digital greeting card to Mars aboard the Phoenix lander, an unmanned space probe, on a mission scheduled for launch next August.  From Los Angeles, VOA's Mike O'Sullivan has more on the message from Earth to Mars.

Space scientist Bruce Betts says it is the perfect gift for the holidays.

"People can give the gift of sending people's names to Mars," he said.  "The Planetary Society is providing a mini-DVD for the Phoenix mission that is going to Mars, launching in 2007, and on that DVD, we will carry names of people or dogs or whatever you want, that want to send their names off to Mars."

At the organization's web site,, people can also print a certificate showing that their name is going to the red planet.

The society's Lu Coffing says response has been good.

"We have over 50,000 people that have signed up, and they're from all over the world," he said.  "We don't know exactly where, but we do know they're from everyplace."

It is all part of an educational campaign to alert the public to the Phoenix mission, a space project that should expand our understanding of Mars. 

There are already DVDs on Mars with the names of four million space enthusiasts, carried aboard the Mars rover missions.  Betts says this disk will have fewer names, but will contain additional information on how Mars has inspired humans here on earth.

"We're actually carrying content we call Visions of Mars, which are from some of the great literature and art about Mars that have been produced over the years, from people like Arthur C. Clarke and Ray Bradbury and Carl Sagan," he said.

Those writers of science and science fiction have kept Mars alive in the public imagination as researchers develop a better understanding of the planet.

The Phoenix mission will be the first to visit the polar regions of Mars.  An earlier spacecraft, the Mars Polar Lander, was lost as is descended to the south pole of Mars in 1999.  Phoenix will land in the northern polar region, which shows evidence of ice just beneath the surface.  The lander has a robotic arm that can dig trenches half a meter deep.  It will analyze samples of soil and ice in a portable laboratory, then radio the data back to earth.

Scientists believe water existed in liquid form on the Martian surface some time in the distant past, and recent images suggest a tantalizing possibility.  Pictures taken by the Mars Global Surveyor show a change in the planet's surface that suggest water could have flowed there recently.

Betts says the presence of water, while unproven, could mean the presence of life.

"It further opens the possibility that not only may there have been life in Mars' past, but there may be now," he noted.  "Now, we're talking little microbes, not little green men, but still interesting."

He says Mars is very different from earth, yet it is the planet most similar to our own in the solar system.

"And if there ever was the possibility of life evolving, it's certainly one of the most probable in our solar system besides earth," he added.  "And yet while being similar to earth, it also has the largest mountain in the solar system, the largest canyon, and it has clouds.  A lot of things are very familiar, but yet different."

If the U.S. space agency NASA keeps to its current timetable, humans should return to the moon by 2020, and use the moon as a base for a human mission to Mars.  When they arrive, the digital greeting from earth should be waiting there for them.