This has been in the news all week. Scientists have found exoplanet around Alpha Centauri-B. This planet is in highly close orbit around Alpha Centauri-B. While this planet it self does not support life in any form. It opens up the possiblity that Alpha Centauri-A and B might have planets with life on them. Earth has life and is not so unique in my view.
This also makes Alpha Centauri A and B prime targets for searching alien civilizations close to our own solar system. But Alpha Centauri is just 4.37 light years away from Earth. But that means any radio signals are just 4.37 months reaching Earth (give or take). This also makes for a better signal detection at this short distance. If there is any civilization on Alpha Centauri A or B we have no way of knowing it state of technical levels. They might be more advanced then us, or they might be less advanced then us. Or they might still be in caves and really primitive. There is no way to know for sure. There is also a possibility that just life might exist in Alpha Centauri A-B system. But without any civilization at all. There is also chance if there was a civilization in the Alpha Centauri A-B solar system that it is long gone for one reason or other. Whatever the case actually is. This planet is a good hope that more planets might exist just 4.37 light years away from Earth.
But one thing is clear. We are never going to know without science studies in that direction. It is also my view that we need to study our closest star better then we already do. This applies mostly to the stars that are close to our own sun in size and brightness. Since the chance of finding planets like our Earth is highest around such stars. Rather then larger and heavier stars. Like blue giants and such. In that case. I think there might be planets around Sirius (8.6 light years away). But I do not think any such planet is likely to have any life on them. But I might be totally wrong in this estimate. But the only way to find out for sure is to study space, as it is human race most important step into the future.
News about this discovery
Next Door Neighbors? Earth-Sized Planet Discovered in Nearest Star System to Us (Universe Today)
Exoplanet around Alpha Centauri is nearest-ever (BBC News)
Alpha Centauri 3 (Solstation)
Sirius 2 (Solstation)
Alpha Centauri (Wikipedia)
This is a simple question. With no simple answer. Currently there are no evidence what so ever that aliens have ever visited planet Earth. But given how primitive human civilization is. It is not hard to imagine that aliens going past our solar system to ignore us, or just take long range scans. Be that from far away from the Earth or in a high orbit above the Earth where we can not detect them.
But as mysteries goes. This one is going to be solved one day. I not know yet if I am going to see that day. But one can hope do so.
The question can we hear aliens has an other side to it. That side is do alien hear our radio signals. This question has been asked and little bit answered also. It has been calculated how far out the radio signals go out from Earth in every direction. As the technology goes it does not look good for radio signal from Earth. Given the bandwidth that radio signal has to have to use in order to carry signals, as picture and audio to be detected.
In terms or radius on where our radio signals can be detected. I would not be surprised that common radio signals are not detected outside our own moon. The strongest one might be detected on Mars or even Jupiter. But beyond that they are not going to be detected in my option. So if aliens detect our radio signals, they are going to get rather close to Earth to do so.
This is might also be the reason why we here on Earth are not detecting any signals from other civilization. The transmission used on those worlds, if they are there to start with are not strong enough to reach our solar system. Our only chance of detecting alien signals might be to look for narrow band signals that can travel an long distance in interstellar space. But for us to find alien radio signals. We have to go out there and look for them the hard way.
There most likely is an alien civilization close to our own solar system. But we are just unaware of it due to the fact that we are unable to detect its radio signals due to distance. If they are present to start with. As not all alien civilization might be using radio signals, or be on that technical level yet.
Section – F.06 How far away could we detect radio transmissions?
During the night there was an M9 solar flare on the sun. This is almost an X-flare according to spacewatch.com. There is also an solar radiation storm heading it’s way to Earth at this moment. It is expected to be S3 in size. But that means that computer might reboot, mobile phones might get weaker signals and so on. A CME is expected to hit Earth tomorrow around 14:18 UTC.
More information on this can be found on Spaceweather.com. Both the progress of this solar radiation storm and updates on the CME. Solar storm weather scales can be viewed here.
I have found that in all the debate about possible life and possibility of an civilization out there. The main problems is that we do not know if the civilization out there is using any radio technology. Even if they do. The question also remains if we get any of there signals to Earth. As the laws of physics say, radio signals can only go so far given certain amount of signal strength in any given radius. This is the complex way of saying that we might not be getting any signals because we are outside the coverage area of the civilization that we are looking at. Some civilization out there might not even be on the radio level technology at current moment. Even if we are there at present time.
I do not know if SETI or related areas have looked at the stars (solstation.com) in less then 20 light years distance from Earth. There have been some speculations on the distance on how far away the signals need to be so they can be detected. But one thing is for sure in my mind. It is almost impossible to detect an radio signal from other civilization if they are using anything remote close to our own technology.
The question on passing ships is an big one. But then an one-off signal should be expected and it might not repeat at all. It is also impossible to know how and often alien ship would travel trough our own solar system.
This is all just questions that are going to be answered one day. But it might take few more decades until it this questions are answered.
Blog post updated at 01:53 UTC on 11.01.2012.