The discovery of an Earth-like planet near us.
The search for extraterrestrial intelligent life
The most Earth-like planet yet discovered has been found right in our neighborhood according to a report from the journal Science in the 2014-APR-18 issue of the L.A.Times
By sifting through observations from more than 100,000 distant stars, astronomers say they have discovered the first definitive Earth-sized planet that orbits in a habitable zone where water could exist in liquid form â€" a necessary condition for life as we know it.
Scientists don't know whether the planet has water or a protective atmosphere. But they said the landmark discovery gives astronomers great hope that a bumper crop of Earth-like planets is waiting to be found nearby.
"This is really a tip-of-the-iceberg discovery," said Jason Rowe, an astronomer who spent a year analyzing data gathered by the Kepler space telescope.
The planet is 10% bigger than Earth, and its parent star is a red dwarf, smaller and dimmer than our sun but that is good news because red dwarfs are the most common star in our galaxy
UC Berkeley astronomer Geoffrey Marcy, who discovered the first exoplanet said. "This is the best case for a habitable planet yet found. The results are absolutely rock solid."
The discovery marks a milestone in the quest to find planets that are not just Earth-sized, but truly Earth-like, said Doug Hudgins, NASA's program scientist for the Kepler mission.
Out of 1,800 or so confirmed exoplanets, fewer than two dozen are in a habitable zone, where it's not so hot that water would boil off into space and not so cold that it would remain permanently locked in ice.
Kepler-186f is also relatively close to us, in galaxy terms, since it is about 490 light-years away. It circles its home star, Kepler-186, in just 130 days. Of the five planets in the system, its orbit is furthest out.
The orbit of Kepler-186f would fit inside that of Mercury but since its star gives off less energy than our sun, it is still in the habitable zone.
Some scientists have argued that M-dwarf stars such as Kepler-186 may not be hospitable to life, since they tend to produce more flares and damaging radiation than larger and brighter G-type stars such as our sun. However, that might result in a faster rate of evolution for life forms that live in the water and under the surface of the planet.
"I believe that planets are very diverse and a whole range of them could be habitable," said Sara Seager, an astrophysicist at MIT who was not involved in the study.
That's an encouraging sentiment, given that planets like Kepler-186f could be easier to find than planets exactly like Earth. Before it was hobbled last year by a broken gyroscope that robbed it of its precision-pointing ability, the Kepler telescope stared at a patch of roughly 150,000 stars and watched for dips in the starlight as planets passed in front.
Based on how frequently such dips in starlight appear, scientists can calculate how quickly a planet is circling â€" and thus, how close to its star it must be. They can estimate a planet's size by measuring the depth of the shadow it casts on its star.
Close-in planets with shorter orbits complete these transits more often, which makes them easier to find. Around our sun, those planets would be baked. But around a red dwarf like Kepler-186, the climate could still be mild.
Such planets are also easier to find because they block relatively more of their stars' light. And given that M-dwarf stars account for 70% of the stars in the Milky Way, there could be billions of Earth-sized planets in the galaxy waiting to be discovered.
Assuming that 10% of M-dwarfs within 100 light-years of us have an Earth-sized planet in a habitable zone, there could be 10 to 20 in that relatively close range, Rowe said.
I predicted, in a book about the Jewish mystical tradition, that I wrote more that 30 years ago that based on statements from the Kabbalah, we would find evidence of extra-terrestrial life during my life time, and encounter extra-terrestrial intelligent lifeforms within the next century or two.
At that time we had not one extra-solar planet had been discovered and some scientists claimed that solar systems were exceedingly rare.
They were wrong. The hunt for planets outside of our own Solar System has made remarkable advances in recent years.
The first was found just 20 years ago; now, nearly 2,000 have been spotted - many by the Kepler telescope.
Now scientists estimate that most stars have planets, although very very few are habitable.
The SETI Institute is dedicated to the search for intelligent life on other planets, and identifying potentially Earth-like planets closer to home would mean that the radio signals our civilization sends into the universe could reach our theoretical neighbors in a matter of decades, Rowe said. If humans ever develop high-speed interstellar travel those Earth-like planets would probably be the best ones to visit.
My book on Jewish mysticism contained a chapter on ETIL (extraterrestrial intelligent life). There I explained the formula of Professor Drake, a founder of the SETI Institute, for estimating the probability of ETIL in our galaxy.
The first of seven factors in the Drake equation was the percentage of stars with planets. I conservatively estimated that 10% of stars like out sun would have a least one planet. The most recent scientific estimate (2012) is that each star of the 100+ billion in our Milky Way Galaxy is estimated to host "on average ... at least 1.6 planets."
Of course, some stars have 3, 4, or more, planets and some have no planets; but it is very likely that a majority of main sequence stars do have planets. This supports my assertion, based on Kabbalistic teachings, that God didnâ€™t create a galaxy with over 100 billion stars, and then leave it devoid of intelligent, spiritually aware lifeforms, with only one exception.
I now believe the first earth size planet, at the right distance to support an atmosphere and carbon based life, (the second factor) will be discovered in the next few years. Then within the next generation scientists will discover life bearing planets (factor three).
But our discovery of ETIL extraterrestrial intelligent life will depend not on our scientists, but on our own moral efforts, because the last -- and most important factor, is primarily a spiritual and moral factor.
The vast distances of interstellar space means that even at the speed of light (186,000 miles a second), communication between advanced intelligent lifeforms is more likely to occur over many generations, rather than decades.
But even that is not the key factor. The last and most important of the factors, the spiritual or moral factor is: how long will an intelligent technologically advanced civilization survive.
If the lifetime of technologically advanced societies is only measured in centuries rather than millenniums, the chance that any two would be living in the same area, and in the same era, are extremely remote.
The answer depends on each species achieving on its own planet a world wide state of peace and global harmony; rather than destroying their own world through war or some type of pollution.
If self destruction is the norm, the chance that any two intelligent species will be alive in the same era becomes exceedingly remote.
If the Divinely inspired prophets of the Hebrew Bible, who spoke of an eventual Messianic Age are correct for us here on planet Earth, (and thus for all ETIL; God is the God of the entire universe), then contact with ETIL is inevitable.