DiscussMormonism.com

I'm talking with someone on a traditional Christian forum who is trying to tell me that a consensus of astronomers have concluded that there probably are no habitable planets in the universe except for planet Earth. He says there are over a hundred variables that have to do with whether a planet is habitable or not, and apparently they have to be just right, and he says that there aren't enough planets in the universe with those hundred variables for it to be likely that another planet has all those variables with the right values. I asked him who the astronomers are that have come to this conclusion and he gave me one name, Hugh Ross, almost certainly Hugh Norman Ross, B.Sc in Physics from the University of British Columbia and Ph.D. in astrophysics from the University of Toronto. Does anybody have any opinions on this guy? Is it true that astronomers of today have given up on finding habitable planets in the Milky Way Galaxy? Any information would be appreciated.

While we're at it, this same poster claims that when the Sun becomes a Helium Star and therefore expands to consume Planet Earth, that Mars will very likely be habitable by then, and he thinks Mars will be the New Earth of Revelation fame. Is this plausible? I have some reason to believe that when Earth gets consumed Mars will not, but the Sun will be a lot closer to Mars than it was in the past. Will the Sun be far enough away from Mars to allow Mars to be habitable?

KevinSim wrote:I have some reason to believe that when Earth gets consumed Mars will not, but the Sun will be a lot closer to Mars than it was in the past. Will the Sun be far enough away from Mars to allow Mars to be habitable?

Something 5 billion years into the future could best be answered by the Quorum of the Twelve. It is possible Mars could be anointed and blessed that it may have strength in the huge south pole crater and a sun protection factor of one million.

KevinSim wrote:I have some reason to believe that when Earth gets consumed Mars will not, but the Sun will be a lot closer to Mars than it was in the past.

What is the reason?

In considering finding life on other planets, consider this: let's say we get a radio wave signal that is unmistakably intelligent. Now let's assume that it is within the near galactic neighborhood - say 30 light years. How long would that civilization have to exist before we would answer back and there could be communication?

It's not just finding life on other planets. Finding life on other planets at the same time human beings are on earth is the challenge.

According to Wikipedia, Hugh Norman Ross is a 73-year-old Christian minister and apologist who does indeed have a PhD in astrophysics from a respectable school. He submitted his dissertation in 1972, and doesn't seem to have kept up with research much, so his knowledge would seem to be pretty dated by now. He's an "old Earth creationist"—so, not completely wacko—but I'd say he's idiosyncratic in some of his views.

Before reading this thread I had never heard anyone argue that Earth is likely to be the only habitable planet in the galaxy, let alone the universe. So this is definitely not a consensus view among astronomers.

No-one knows how rare or common Earth-like planets may be. Most exoplanets discovered so far have been very un-Earth-like: with a few exceptions, they are mostly huge planets orbiting quite near their suns. The main way of detecting exoplanets has been through their gravitational effects on their suns, and this obviously works better the bigger the planets are, and the closer they are to their suns. So everyone assumes that there may well be many more smaller planets orbiting at distances that are neither too hot nor too cold ("Goldilocks zones"), but we just can't see them yet.

How much more does it take to make a habitable planet, beyond being the right size and the right distance? Are there important conditions of geology that can vary widely? Is it somehow crucial to have a large moon, as Earth does? No-one knows these things.

When our sun goes red giant, in about five billion years, it will likely toast the Earth but leave Mars still orbiting. Mars will surely be too hot to be habitable at that point, however, and the solar wind will probably strip off any atmosphere Mars may have left at that point. Not really worth worrying about, though. Five billion years is a long time.

I have a question wrote:

KevinSim wrote:I have some reason to believe that when Earth gets consumed Mars will not, but the Sun will be a lot closer to Mars than it was in the past.

What is the reason?

Because I remember hearing that in five million years the Sun would expand to engulf Earth's orbit. The document that told me that said Earth's orbit, not Mars' orbit. Granted that's not much reason, but that's all I had.

Physics Guy wrote:No-one knows how rare or common Earth-like planets may be. Most exoplanets discovered so far have been very un-Earth-like: with a few exceptions, they are mostly huge planets orbiting quite near their suns. The main way of detecting exoplanets has been through their gravitational effects on their suns, and this obviously works better the bigger the planets are, and the closer they are to their suns. So everyone assumes that there may well be many more smaller planets orbiting at distances that are neither too hot nor too cold ("Goldilocks zones"), but we just can't see them yet.

How much more does it take to make a habitable planet, beyond being the right size and the right distance? Are there important conditions of geology that can vary widely? Is it somehow crucial to have a large moon, as Earth does? No-one knows these things.

When our sun goes red giant, in about five billion years, it will likely toast the Earth but leave Mars still orbiting. Mars will surely be too hot to be habitable at that point, however, and the solar wind will probably strip off any atmosphere Mars may have left at that point. Not really worth worrying about, though. Five billion years is a long time.

Thanks, Physics Guy; this is precisely the information I need.

KevinSim wrote:Because I remember hearing that in five million years the Sun would expand to engulf Earth's orbit.

That would be five BILLION, not merely five million.

Dr. Shades wrote:

KevinSim wrote:Because I remember hearing that in five million years the Sun would expand to engulf Earth's orbit.

That would be five BILLION, not merely five million.

I stand corrected. Yes, it is five billion. I'm surprised I made that mistake; I meant to type five billion.

Creation science.