NASA: Humans Will Prove ‘We Are Not Alone In The Universe’ Within 20 Years

connecticut.cbslocal.com ^ | 7/15/2014

[RoosterRedux]

Cambridge, Mass. (CBS CONNECTICUT) – NASA predicts that 100 million worlds in our own Milky Way galaxy may host alien life, and space program scientists estimate that humans will be able to find life within two decades.

Speaking at NASA’s Washington headquarters on Monday, the space agency outlined a plan to search for alien life using current telescope technology, and announced the launch of the Transiting Exoplanet Surveying Satellite in 2017. The NASA administrators and scientists estimate that humans will be able to locate alien life within the next 20 years.

“Just imagine the moment, when we find potential signatures of life. Imagine the moment when the world wakes up and the human race realizes that its long loneliness in time and space may be over — the possibility we’re no longer alone in the universe,” said Matt Mountain, director and Webb telescope scientist at the Space Telescope Science Institute in Baltimore, which plans to launch the James Webb Space Telescope in 2018.

“What we didn’t know five years ago is that perhaps 10 to 20 per cent of stars around us have Earth-size planets in the habitable zone,” added Mountain. “It’s within our grasp to pull off a discovery that will change the world forever.”

[RoosterRedux]

My hometown was hit with a rash of UFO sightings back in the late 60's. I was away in college but the entire town was scared to death.

The sightings were up close and personal. And it wasn't swamp gas because most folks around here are quite familiar with swamp gas (the famous Cogdell Light is only perhaps 25 miles away and EVERYONE back in the 60's had seen it).

[Haiku Guy]

The point of my first post was that we run all of these numbers, and conclude that there are probably X number of planets that have intelligent civilizations (using whatever BS methodology we choose), without accounting for the fact that the duration of an intelligent civilization from founding to self-imollated cinder is but an eyeblink when measured against the ages of the planets. The question of how many planets may have had an intelligent civilization as compared to how many planets have an intelligent civilization at any particular point in time are two very different calculations.

[fishtank]

Baloney.

Calc how many star systems the radio signals have hit. It should be in the millions by now. Then calc how many systems the evos say should have life.

By the evo math, the Vulcans would have been here a long time ago, answering our “phone home”.

Why aren’t they here yet?

BECAUSE THEY DON’T EXIST!!!

[TigersEye]

You’re argument is with known facts. Mathematics is not baloney and neither is the speed of light which radio transmissions travel at or near.

[blackdog]

No, we put on a gorilla suit with red reflectors glued on by the eye holes and run across roads late at night.

[TigersEye]

There is also this fact. Our transmissions would be extremely faint after 10s of light years of travel.

[TigersEye]

Imagine how much fun that would be on a planet that had no gorillas! ;^)

[Mycroft Holmes]

Calc how many star systems the radio signals have hit. It should be in the millions by now

---

Eh, seems pretty high to me. According to Ask an Astrophysicst the answer is roughly 15 thousand.

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[Sherman Logan]

I would say the fats at this point are that we have no data.

Their assumption seems to be that 10% of stars have planets in the habitable zone and 1% of those planets support life.

The problem is that there is no reason to plump for 1%, as opposed to 10%, .000001% or zero. None at all. Percentage just picked out of the air.

[TigersEye]

Calc how many star systems the radio signals have hit. It should be in the millions by now

Other calculations put the number of solar systems within 100 light years of earth at about 170,000. Still a far cry from millions. 100 light years is a good measure because the oldest radio signal from earth has traveled about 110 light years. How Far Have Our Radio Signals Traveled From Earth? The other problem is also addressed at that last link...

While it’s interesting to imagine how far our radio signals have traveled into space, it’s extremely unlikely that an alien civilization will be able to catch the latest episode of ‘I Love Lucy’. This is thanks to the inverse square law. In Layman’s term, it’s a form of signal degradation.

As radio signals leave earth, they propagate out in a wave form. Just like dropping a stone in a lake, the waves diffuse or “spread out” over distance thanks to the exponentially larger area they must encompass. The area can be calculated by multiplying length times width which is why we measure it in square units – square centimeters, square miles, etc. This means that the further away from the source, the more square units of area a signal has to ‘illuminate’.

In addition you have to figure the odds of life being present in any given solar system and the number drops a lot from that 170k. Then figure in the odds of that life being intelligent and technologically capable of "listening" for radio transmissions and it is narrowed down to some small fraction of a percentage point.

[Mycroft Holmes]

At your reference I saw the claim:

"There are a total of 115 stars in 81 star systems within 20 light years from the Earth."

But no calculation about 100 light years containing 170K stars.

[TigersEye]

It's at the top of the page. You have to click the link "show answer." It opens and displays this...

A few years ago the Hipparcos sattelite measured distances to ~120,000 nearby stars, so somewhere there is an exact answer to this question. I don't know to what magniture Hipparcos could measure parallaxes for, and whether it could see the dimmest M dwarfs 100 light years away, so it may or may not have observed all the stars within 100 light years. Given how dim M dwarfs are, I would guess it probably didn't. In other words, somewone probably figured out exactly how many stars in the Hipparcos catalog are withi 100 lightyears, but I don't know that answer, or whether that ould be all of the actual stars within 100 lightyears (~30 parsecs). So, here's an estimate. In our part of the Galaxy, the average distance between stars is about 1 parsec. (30 PC~100 ly). 4pi/3* (30 PC)^3 is about 113,000 stars out to a distance of 30 PC or about 100 lightyears. Now, about half of the star systems are binaries or multiple systems, so 113000 + 113000/2 is about 170,000 stars. That's a lot! As for how many have planets, well, we have detected several hundred extrasolar planets, but they are almost all very large planets orbiting very close to their parent star, simply because this is what is easiest to detect. The more we look, the more we'll probably find, so there are probably many thousands of planets within 100 ly of our solar system.

[Bubba_Leroy]

Of course, "Earth-like" does not mean any of them have some kind of life, much less "intelligent life".

The most "Earth-like" planet ever discovered is the planet Venus. It is almost exactly the same size as Earth and close to the same orbit. If you were looking at it from several light years away it would be virtually indistinguishable from Earth.

[right way right]

So, if there’s other life elsewhere the next question would be does it matter to us, them, or neither?
With all that troubles the world today does it matter?
I cannot help but feel the vastness of the universe reflects the vastness of our non-understanding of God. When I am with God he will clue me in on some things. I look forward to it.

[Mycroft Holmes]

Thanks, missed that. The 170K number is a bit disingenuous as it counts binaries as two systems. And if you want to pretend to count M dwarfs...

[hattend]

Like Global Cooling predictions in the 70’s, warming in the 90’s...who will remember this prediction when it doesn’t pan out?

[Bubba_Leroy]

There is a long list of factors that makes Earth a unique place.

You listed several of them. Without a large moon and a molten core, Earth would look a lot like Venus.

In addition, there are many aspects of our solar system that may make it unique for the formation of life. For example, there have not been any large supernovas nearby that would have sterilized any newly formed or forming life with high levels of radiation.

Then, if you get simple life, it may take several world wide catastrophic events (like asteroid strikes and repeated ice ages) to keep resetting life until something complex is forced to evolve.

So even if we someday discovery microbial life somewhere else in our solar system, it doesn't necessarily mean that there is life (simple or complex life) in other solar systems.

The list is probably endless.

[TigersEye]

The source wasn’t trying to answer the question of how many stable solar systems with planets there are but it was one of the few sites I could find in a simple search that had some answer as to how many stars are within 100 lys of earth. It’s clearly a lot less than “millions.”

[papertyger]

Threads like this always prompt me to remind FReepers to read Michael Crichton’s critical assessment of the Drake Equations....

[Bubba_Leroy]

Aliens (X) master the technology and sophistication to build space craft which travel at light speeds, avoid black holes, asteroids and space rubble, gravitational pull of all sorts of phenomenon, solar radiation, temperature control, hydration, nutrition, and arrive at a spot one trillionth of a speck, enter our atmosphere without burning up or being detected, and when they get 100 feet above the ground they need to turn on bright lights to see where they are going?

Not only that, but they communicate using CB radios!