霍金、扎克伯格寻找外星生命（在线收听）

Hawking, Zuckerberg to Search for Life in the Universe 霍金、扎克伯格寻找外星生命

It is one of the oldest questions ever asked: Are we alone or is there other life out in the Universe?

Last week, an international team of scientists and businessmen launched a project they hope can answer that question. They announced plans for a huge space exploration program. Its goal is to find alien life in space.

The team includes British physicist Stephen Hawking, Russian-born billionaire Yuri Milner and American Mark Zuckerberg, who founded Facbook.

Their project is called Breakthrough Spaceshot. It will develop and build thousands of robotic vehicles that can speed through space.

Their first goal is to explore the near est star system, Alpha Centauri. It is about 40 trillion kilometers — or 4.37 light years – away from Earth. Once launched a spacecraft would have to travel 20 years to get there.

The way they will make it happen is like something from a science fiction story. Crews on Earth would use powerful laser beams to power extremely small vehicles  through space.These spacecraft would travel much farther than any other spacecraft built to date.

Estimates say the project will cost from $5- to 10-billion.

Yuri Milner is giving the project $100 million to get started.

Last week, Milner showed a model of the spacecraft to reporters in New York.

“This is a starchip, a gram-scale wafer containing cameras, photon thrusters, power supply and navigation and communication equipment.”

The starchip is a computer chip about the size of a large postage stamp. Each one will cost no more than an iPhone. The chip will have a light sail — very thin material that can open in space and move the spacecraft forward. Together the chip and the sail are called “nanocraft.”

The team plans to launch a “mothership,” which then would be put in Earth’s orbit. The mother ship would release thousands of the nanocraft.

Their light sails would open and crews on Earth would fire laser beams on the light sails. That would push the nanocraft. They will travel at about 20 percent of light speed.

Today’s fastest spacecraft would take about 30,000 years to reach the Alpha Centauri system. But once this new nanocraft technology is ready, supporters say, it can shorten that time -- to just 20 years.

Stephen Hawking said the distance between Alpha Centauri and Earth can be crossed within a generation. The British scientist speaks through a computerized voice:

“I believe what makes us unique is transcending our limits. Gravity pins us to the ground, but I just flew to America.”

Hawking added, “Today we commit to the next great leap in the cosmos, because we are human and our nature is to fly.”

Other scientists have signed on for the project. Freeman Dyson is with the Princeton Institute for Advanced Study. He thinks scientists might find something interesting before the nanocraft reach Alpha Centauri.

"The space between here and Alpha Centauri is not empty, that it's not just a huge void which you have to cross in order to reach something interesting on the other side. On the contrary, there are thousands of objects in between.”

Dyson believes that life is more likely to be found on an asteroid, or space rock, rather than a planet.

The project is just now taking shape. The first step is about 20 years for research and development. There are still many details to work out about how this project will work, technically.

Next would come the launch of the mothership, and the release of the nanocrafts.That would be another 20 years to get to Alpha Centauri.

Then, people on Earth will have to be patient. It will take at least four more years for any of the information collected to reach Earth.

Avi Loeb teaches astronomy at Harvard University. He explained the group wants to interest young people in the project.

He said, “our goal is to get people all over the world involved, especially young people that will be around when we get there.”

Future improvements in technology could change the timeline and help speed up the project. But for now, a person born this year may be in his or her 50s when those nanocraft reach their target.

Words in This Story

alien – n. a creature from somewhere other than Earth

ambitious – adj. something that will take a lot of time and effort and is difficult to achieve

gram-scale wafer – n.  a small object that weighs about a gram

photon thrusters – n. a device that helps move a spacecraft forward

transcend – v. going beyond or rising above normal limits

void – adj. empty

on the contrary – phrase. the opposite

beam -n.  a line of light

postage stamp – n. a small square on a letter for payment to mail

commit – v. to say you will definitely do something

cosmos – n. the system that is the universe

timeline - n. a schedule of events