
(CNN) – It's a question science fiction writers asked long before man could fly: Are we alone? And if we're not, are we in trouble?
The cosmologist Stephen Hawking is issuing a warning in a new documentary, saying that we are not alone, that there may be hostile life out there, they may be hungry, and we should be careful about going out looking for them.
NASA just announced it's going ahead with a new plan to search for extraterrestrial life. It includes sending a lander to Mercury and exploring the moons of Jupiter and Saturn.
James Green is the director of NASA's planetary science division and he joined us on Thursday's American Morning to discuss the possibilities of life beyond Earth.


I am supporting NASA in their effort to find INTELLIGENT beings. They are there, in the Milky way! There are several planets in the Eastern part -direction West of Norway.
The planets have blue and yelow stars for the sun. And all of them are at a safe distance fron the monster black hole.
I wish you luck and the best success NASA!
I think is the best money NASA could spend, on finding extraterrestrial life forms. Although its a shame constellation was canceled, Imagine what sources we could find that would benefit us in the long run, I agree with NASA and the best of luck to them.
If you say no NASA the government will give the $ to the corporations to do this...
We are humans alright, & we will hae this built in adventure to go out & seek out new life fourms. Yes it's all interesting and nice to know....BUT at costs indeed.
npare, you are a mistrusting skeptic – why do you think they would hide the info? never
understanding life elsewhere could be critical to our survival in the event of unforseen natural disasters
the research is an enormous catalyst to innovative developments in other areas in the same way defense spending has been
nasa's mission is not saving the planet – that is elsewhere in the gov – nasa will not be removed from existence – therefore this is not a zero sum game
let's go learn about the forms of life that inevitably exist on jovian and saturn moons as it will have a profound impact on us when we find it – for the better
Hey, did we forget the UFO's, Steven Hawkins got everyone worked up!!! Ask him to tell them to help feed us!!! USA is the way!!!
I think that this is very exciting! I'm confident that we won't be killed by sentient life, since we're only looking in our own solar system right now.
@npare: if they're publicly saying that they are looking for life, what makes you think they would cover up any actual findings of life?
Their looking for oil. Can't have oil without life. 😉
Well let's suppose there is a reason they are not telling us. It must be closely related to people who think like you. Why bother on the future, it's not like we want to progress, make discoveries and anticipate any threat.
You are wrong. NASA is the only institute on earth that bothers to ask questions that people like you don't even dare to dream! Go for it NASA!
Wow!
That's a big turnaround for NASA! Did you know that ever since Viking lander mission in 1976, NASA has forbidden any proposals that explicitly looked for life on Mars? You could look for water, just not life. That's why Gil Levin's "Labelled Release Experiment", which returned evidence for life on Mars in 1976, was never confirmed.
Do you suppose that this is just a way to justify abandonning the Moon?
I think i want NASA to stop. Save that money and put it to good use like saving the earth. It's not like they are going to tell us if they find life in other planets. So why bother. No more money for NASA!!
A very good Idea,despite S.Hawking's "Curious" mis-givings.
I wish NASA the best of luck in it's effort to "feed" Mankinds hunger for knowledge about other forms of (Intelligent?) Life! With the right attitude , I am sure we won't be ET's appetizer. Right?
David M, Kerrick,Ph.D
Philadelphia,Pa
Space exploration today is the same as when Columbus set out to prove the world was round centuries ago. Will we find anything? Well probably, but it will be a few years.
Who knows, there could be minerals on our neighbor planets that could solve many of the problems we have on earth today and if something is found, it could take years to develop methods to transport them back to earth, but we know we can do it in time.
To say we will find life, it is unlikely we will find life on our neighboring planets, but I am certain that somewhere in the never ending space there is life, and it may be more intelligent than we are.
Lets not forget that space is so vast, that our planet earth when compared to space, couldn't be found with the most powerful microscope we have, which means that other planets don't know if we exist either!