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Would Centaurians know we exist?

In which we ask the question: If we were denizens of the Alpha Centauri system, and we were looking for extra-terrestrial life from there, using the technology that we have here today, would we be able discover Earth, and/or human life?

alien

To borrow from the brilliant Karl Popper, as long as the existence of extraterrestrial life or intelligence is not falsifiable (meaning you would have to check every exoplanet around every star), you could continue the search for ET forever. I’m not sure that this is in line with the scientific method; ideally you’d be looking objectively at what’s out there and trying to understand what you see from that standpoint.

Radial velocity

Let’s start by pondering our methods for exoplanet detection. One of our most successful is the radial velocity method. It’s not an accident that the first planets we have found this way, are predominantly large planets, in tight orbits around relatively small stars. These simply the easiest planets to find. Unfortunately for the general public, this gives the impression that most planets are very large, in tight orbits around relatively small stars!

On the other hand, our island Earth orbits the sun at 1.0 AU. Its orbit causes the sun to deviate by a mere 0.09 m/s, or 9 centimeters per second. This leads me to wonder what our current best precision is? Only about 1.0 m/s. That’s right, we would need to increase precision by about 100 times in order to detect Earth from Alpha Centauri using the methods we have right now.

Notice that I didn’t say “see” the Earth. That requires a set of optics that we don’t have in orbit yet. Perhaps the James Webb space telescope will come close to that. It will be launched in a few years.

Transit photometry

Using transit photometry, another way of detecting exoplanets, the actual size (rather than just its mass) can be estimated. But for a planet orbiting a Sun-sized star at 1.0 AU, the probability of a random alignment producing a transit is 0.47%. In other words, since the exoplanet has to be lined up just right, the chances of detecting a random planet around any particular star is about one in one hundred (1:100).

Radio emission (SETI)

If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth?

Many times, we hear that our radio transmissions, which date back many decades, are flying out to outer space at the speed of light. That our broadcasts from 40 years ago are reaching stars that are 40 light-years away. Might xenomorphs be puzzling over TV broadcasts of I Love Lucy or Adolph Hitler’s early radio broadcasts?

That’s partially true. However, there are some problems. Firstly, the vast majority of our radio signals are very weak and are – in effect – aimed at local terrestrial receivers rather than turned up to the stars.

Secondly, the strength of the signal diminishes as the inverse square of the distance. In other words, it would drop off extremely quickly. Even from Alpha Centauri, we would probably not be able to detect radio transmissions from Earth.

Mix that in with these facts: our scientists, possibly frightened by too many viewings of Ridley Scott’s movie Alien, are extremely reluctant to beam radio messages deliberately into space. And surely civilizations on other planets have equally cautious scientists!

Also, when we do think that we have received a signal from outer space, we wait for it to be repeated. This is for scientific verification. But the one signal that we have deliberately beamed into space (the fools!) was NOT repeated. So again, we can imagine alien scientists, possibly detecting one of our signals, and waiting for it to repeat, so they can verify it.

Long story short (or perhaps it’s too late for that) we are not ready to say “yes” or “no” about whether we have alien companions out there in the universe. Baby steps, we are still making baby steps.

Odds are, there are no aliens

Bayesian reasoning nixes chance for life

…the expectation that life — from bacteria to sentient beings — has or will develop on other planets as on Earth might be based more on optimism than scientific evidence.

Bayesian probability is named after 18th century English mathematician and theologian Thomas Bayes. Yes, you can blame him for bursting your bubble.

But here’s the gist of it. In having ONE earth with ONE example of life and evolution on this planet, we have a sample size of exactly ONE. Statistically, that’s horse feathers; you can’t assume anything about the rest of the universe with a sample size that tiny.

Even by throwing around “magical” words like “billions” or “trillions”, meaning galaxies, stars, exoplanets – it still doesn’t guarantee any success in finding extraterrestrial life.

To borrow from Karl Popper, as long as the existence of extraterrestrial life or intelligence is not falsifiable (meaning you would have to check every exoplanet around every star), you could continue the search for ET forever. I’m not sure that this is in line with the scientific method; ideally you’d be looking objectively at what’s out there and trying to understand what you see from that standpoint.

We may just be all alone on our pretty blue marble.

earthafr

 

NASA Floats Idea for Titan probe

A Submarine on Titan!

“We propose to develop a conceptual design of a submersible autonomous vehicle (submarine) to explore extraterrestrial seas. Specifically, to send a submarine to Titan’s largest northern sea, Kraken Mare.

This craft will autonomously carry out detailed scientific investigations under the surface of Kraken Mare, providing unprecedented knowledge of an extraterrestrial sea and expanding NASA’s existing capabilities in planetary exploration to include in situ nautical operations.

Sprawling over some 1000 km, with depths estimated at 300 m, Kraken Mare is comparable in size to the Great Lakes and represents an opportunity for an unprecedented planetary exploration mission.

This mission would be a logical follow-on to a Titan surface mission such as TiME (Titan Mare Explorer) or even a component of a flagship mission of multiple vehicles.

The mission concept we propose to study will investigate a full spectrum of oceanographic phenomena: chemical composition of the liquid, surface and subsurface currents, mixing and layering in the “water” column, tides, wind and waves, bathymetry, and bottom features and composition.

Measurements of all these aspects of Titan’s hydrocarbon ocean environment can only be made through focused in situ exploration with a well-instrumented craft.

This investigation represents a significant advancement in our understanding of the history and evolution of organic compounds in the solar system, and hence a critical step along the path to understanding the evolution of life here on Earth and potential life elsewhere in the galaxy.

Titan Submarine, or Titan Sub for short, will be a fully autonomous, highly capable science craft that will allow a complete exploration of what exists beneath the waves on another world.

http://www.nasa.gov/content/titan-submarine-exploring-the-depths-of-kraken/

Slim chance for life on Mars

3065b81600000578-3409278-image-a-16_1453331177007What Antarctica tells us about hope for life on Mars

We tend to assume that every sample of surface soil on planet Earth should be crawling with microbes, but in a corner of Antarctica (University Valley), not only one of the driest and coldest (-9 °F mean year-round) spots on Earth, but also high in elevation, scientists have failed to find life (i.e. microbial activity).

Now this would be a big “whoopie-doo!” from most quarters until you realize that these conditions in University Valley would be considered to be utterly luxurious in any place on Mars.

It was a big surprise for NASA. University Valley was specifically chosen to simulate the conditions around the Mars Rover.

Lyle Whyte, McGill university professor, said that if there is indeed no life here, which is what this study indicates, then the likelihood of finding life on Mars, where conditions are even colder and drier, is slim indeed.

“If we cannot detect activity on Earth, in an environment which is teeming with microorganisms, it will be extremely unlikely and difficult to detect such activity on Mars.”

Alien life will be discovered soon – NASA

http://www.nasa.gov/content/finding-life-beyond-earth-is-within-reach/
NASA in 2014 announced that discovering life on another planet is within our reach within 20 years. Mark your calendar now

NASA astronomer Kevin Hand suggested that the moon of Jupiter, Europa, could prove to have a form of life.
Now, that’s kind of a rash statement for a scientist to make, since all we know is that Europa has some form of water. Certainly frozen, with a possibly liquid form deep under that icy crust. That is VERY speculative.

Unless you’ve been pointed to that satellite by someone with more advanced technology.

Maybe that 20 years is not the time frame for the technology to be developed (although we will have powerful exoplanet-hunting telescopes on orbit by that time), but a period for humanity to be become accustomed to the idea that we are not alone.

James Webb observatory

Centauri?

Obviously we have seen evidence of “tidal heating” in some of the satellites of Jupiter and Saturn. So if there are any “Super-Earths” that are orbiting outside of a star’s “Goldilocks zone” then they still might be worth checking out.

This article misses the fact that our planet-finding capabilities are currently weighted towards finding very large planets in very close orbit around very small stars. Using these current techniques, we would not be able to find Earth from Alpha Centauri.

So, we cannot assume that there are NO Earth-sized planets there.

http://astrobiology.nasa.gov/articles/2014/3/18/super-habitable-world-may-exist-near-earth/

Earth is the only known example of an inhabited planet in the Universe, so the search for alien life has focused on Earth-like worlds. But what if there are alien worlds that are even more habitable than Earth-like planets?

A recent paper in the journal Astrobiology examines the potential for so-called “superhabitable” worlds. One such planet might even exist around the stellar system closest to Earth: Alpha Centauri B.

The study was authored by René Heller of McMaster University in Ontario, Canada, and John Armstrong of Weber State University in Ogden, Utah, USA. According to the authors, their collaboration was “inspired by a question John Armstrong asked online during an AbGradCon talk in 2012.”

The Astrobiology Graduate Conference (AbGradCon) is supported by the NASA Astrobiology Institute, and is organized by graduate students and post docs in fields related to astrobiology. AbGradCon provides early career researchers with the chance to discuss research, network and collaborate. AbGradCon 2014 will be held at the Rensselaer Polytechnic Institute (RPI) in Troy, New York. For more information, visit: http://www.abgradcon.org/index.html

To be habitable, a world (planet or moon) does not need to be located in the stellar habitable zone (HZ), and worlds in the HZ are not necessarily habitable. Here, we illustrate how tidal heating can render terrestrial or icy worlds habitable beyond the stellar HZ. Scientists have developed a language that neglects the possible existence of worlds that offer more benign environments to life than Earth does. We call these objects “superhabitable” and discuss in which contexts this term could be used, that is to say, which worlds tend to be more habitable than Earth. In an appendix, we show why the principle of mediocracy cannot be used to logically explain why Earth should be a particularly habitable planet or why other inhabited worlds should be Earth-like.

Superhabitable worlds must be considered for future follow-up observations of signs of extraterrestrial life. Considering a range of physical effects, we conclude that they will tend to be slightly older and more massive than Earth and that their host stars will likely be K dwarfs. This makes Alpha Centauri B, which is a member of the closest stellar system to the Sun and is supposed to host an Earth-mass planet, an ideal target for searches for a superhabitable world. Key Words: Extrasolar terrestrial planets—Extraterrestrial life—Habitability—Planetary environments—Tides. Astrobiology 14, 50–66.

Mirage Men

It’s interesting to see UFO “sightings” given a pass because the alleged witness is with the government. Suddenly employees of the government are reliable and trustworthy!

Not so fast, sunshine.

Here’s a thought for you: Consider whether the UFO phenomenon is nothing more than a psychological operation, courtesy of the U.S. intelligence establishment, developed during the Cold War with the U.S.S.R., with the express intent of hiding the development of advanced (human-developed) weapon platforms – with the desirable side-effect of convincing the enemy that we might have our hands on invincible alien technology.

They wouldn’t do such a thing, you say. Bollocks, they have done much worse. This would cost much less. Their denials simply serve to stir up the crazies even more.