Editor's note: This post is affiliated with the Overheard on CNN.com series, a regular feature that examines interesting comments and thought-provoking conversations posted by the community.
Life, as we know it, needs certain conditions to exist. Readers yesterday had some strong opinions about searching for that life elsewhere, after NASA made an announcement about a new planet outside our solar system:
Edward: "The whole point of this is not whether we are going to get there. It is so people know that mathematically we are most likely not alone. So the more planets with possible water gets closer to proving that point."
nsr007: "You assume that other life forms need water to survive just because the ones on Earth do."
NASA scientists say the Kepler mission has uncovered its first confirmed planet in the "habitable zone" around a star, and are calling the discovery a "major milestone on the road to finding earth's twin." The Light Years post led to discussion about many meaty issues: spirituality, dealing with alien life-forms, space travel capabilities and the mind-bending size of our universe.
But a sizeable portion of the discussion was about what it really means for water to be on other planets.
dave: "Don't we know already know that there's water on Mars?"
Mike: "It's not known with certainty. That's a key part of Curiosity's mission. Also, although they failed to mention it, I think they are referring to planets in other solar systems."
The Professor: "Actually you are incorrect, there is and we do have proof of water on Mars, just in frozen form. There are signs of running water, but no actual firm proof of that. But there are changes that we have recorded through pictures taken using the MRO that show changes on the ground that could be attributed to running water. But the atmosphere of Mars is too thin to allow water to be in the liquid form for long, water tends to sublimate into water vapor quickly because of that."
T. D. Sharkey: "There is water all over the solar system in the form of ice; most water on Earth likely came from comets and other Kuiper type objects colliding with the Earth early in its history. Persistent liquid water is what they are looking for, and that is what defines a planet as being within the habitable zone."
Of course, the planet is 600 light years away, and readers debated the challenges involved in traveling such a distance:
minpin: "At 600 light years that would mean eight generations at average life expectance to reach it at the speed of light. Anyone want to volunteer?"
DT: "If you hit the speed of light, you will reach there in an instant. But, 600 years would have passed on Earth."
JeffinPDX: "If we invest in cryogenics, then yes, I would volunteer to be frozen and sent to explore an alien world."
What do you think about this discovery and the comments from readers? What thoughts and questions do you have? Share your comments below. Or, share your photos, videos and thoughts over at CNN iReport.