"In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters."
Our planet Earth is a tiny speck in one in the very peripheral in one of the spiral arms of the galaxy 'The Milky Way". If the center of our galaxy is "down town", then we live far out on the country side. Will we ever be able to go there or find out what's going on?
According to ESO the chances are that we are not alone in universe. A new result from ESO’s HARPS planet finder shows that rocky planets not much bigger than Earth are very common in the habitable zones around faint red stars. The international team estimates that there are tens of billions of such planets in the Milky Way galaxy alone, and probably about one hundred in the Sun’s immediate neighborhood.
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| Rocky planets not much bigger than Earth are very common in the habitable zones around faint red stars |
Now, when ESO talks about the 'immediate neighborhood' they mean within a distance of 10 Parsec, which is equal to 32.6 light years, i.e. the distance light itself travels in that time. Read the whole article "Many Billions of Rocky Planets in the Habitable Zones around Red Dwarfs in the Milky Way".
In order to escape Earth's gravitation at 9,000 km altitude in "space" an interplanetary rocket needs a speed of slightly less than 7.1 km/s, which is about 6 times the muzzle velocity of a rifle bullet. The moon rockets sent to the moon during the Apollo program all had a speed slightly less than the Earth's escape velocity. This speed put them into an elongated elliptical Earth orbit, to a point where the Moon's gravity would capture them. It took three days to reach the moon. Unless somebody comes up with a new type of rocket drive that allows people to travel faster in space and keep accelerating even after escaping the gravitional force we will not even be close to reach our nearest known star, Proxima Centauri which is 1.29 parsecs away. A mere speed of 10 km/s would require 126 years of travel time. So, it seems we are pretty much stuck here.
Planets with a mass between one and ten times that of the Earth (aka super-Earths) appear to be very common around other stars in the Milky Way. Discoveries of such planets in the habitable zones around stars are very exciting because — if the planet were rocky and had water, like Earth — they could potentially be an abode of life.
“Our new observations with HARPS mean that about 40% of all red dwarf stars have a super-Earth orbiting in the habitable zone where liquid water can exist on the surface of the planet,” says Xavier Bonfils (IPAG, Observatoire des Sciences de l'Univers de Grenoble, France), the leader of the HARPS team at ESO. “Because red dwarfs are so common — there are about 160 billion of them in the Milky Way — this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone.”
Let's say that only one super-Earth in a million carries some kind of advanced life forms. Let's be careful and put the number of super-Earths to only 16 billion, i.e. reduce the 40% probability to only 10%. This still means that there are around 16 million super-Earths only in our galaxy that are abodes of advanced life forms! And why not? After all we can conclude that we have life on Earth, so why wouldn't it be possible that there should be life on other planets in the universe?
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| The search for extraterrestrial intelligence. |
We have come a far way from the old times when Earth was considered the center of the universe with the sun orbiting around us. Copernicus changed that, even if he just replaced Earth with the Sun to be the center of the universe in his heliocentric model. Copernicus started the astronomical revolution that later turned out discoveries that our sun was only one star out of many in a galaxy. Even later on we found out that our galaxy was only one out of many galaxies. What will be the next? Will we find other life forms, or will the mere distance kill such initiatives.
The distance from us to the center of the Milky Way is 8,000 Parsec, approx. 26,000 light years. Unless there are "worm holes" in the space-fabric there is no way we will ever get there. Even when we study the night sky and turn our binoculars towards the center of the Milky Way we will only see what happened there 26,000 years ago. The same applies to radio signals. The search for extraterrestrial intelligence (SETI) is the collective name for a number of activities people undertake to search for intelligent extraterrestrial life, but whatever signs of advanced life forms with the capability of sending out strong radio signals the time and distance will never allow us to connect to each other.
Chances are, however, that if we still hang around here in a distant future from now, we will get closer to a whole set of new potential life carrying planets! The nearest galaxy to the Milky Way is the Andromeda Galaxy. It has long been known that these two galaxies have been heading in the general direction of each other. They are separated by about 800,000 Parsec (2.5 million light-years), but are converging at something like 400,000 km/h, or 111 km/s. The new Hubble data provides fresh insight on when and how a union is likely to unfold, as you can read more about in the article "Hubble times Milky Way and Andromeda galaxy pile-up". The two galaxies are being pulled together by their mutual gravity and the scientists expect them to begin to merge in about four billion years' time. A further two billion years on and they will appear as a single entity. So what will happen to us? Well, the good news is that our Sun's position will be disturbed, but the star and its planets are in little danger of being destroyed.
Above I have only mentioned the Milky Way and the Andromeda galaxy. Today we know there are probably more than 170 billion galaxies in the observable universe. Most of these are 1,000 to 100,000 parsecs in diameter (the Milky Way is approx 30,000 parsec wide) and usually separated by distances on the order of millions of parsecs.
Now, consider the number of potential super-Earths if you multiply the conservative assumption of 16 million super-Earths per galaxy with the total number of 170 billion galaxies in the observable universe...
The universe is bigger and more complicated than we ever could imagine.
Upon talking about stars; perhaps of all the Church Fathers, none shone so brightly as St. Augustine (351-430).
St. Augustine problably hit the nail when he coined the expression 'Deus semper major', that contains the insight that God always transcends our notions and ideas of what God is, e.g. similar to the multiplication of super-Earths in the universe.
Scribes in the old days often wrote DSM in the margin whenever they wanted to point out this fact in a scripture. We should take note of that...
Why should God limit himself to just one single Earth when he took the trouble to create a whole universe? My personal conclusion is that there are, there has been, and there will be, millions and millions of intelligent and advanced life forms out there on different planets.
Just like ESO concludes - the chances are that we are not alone in universe.
The question is; will we ever meet with one of those other civilizations?
Problably not.
Genesis 3-4:
"And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness."
