Number of candidate exo-Earths reduced by Gaia data
Worlds without end: The number of candidate exo-Earths identified by Kepler has now been reduced based on data from Europe’s Gaia telescope.
To date, NASA’s prolific Kepler space telescope has discovered about 30 roughly Earth-size exoplanets in their host stars’ “habitable zone” — the range of orbital distances at which liquid water can likely exist on a world’s surface.
Or so researchers had thought. New observations by the European Space Agency’s (ESA) Gaia spacecraft suggest that the actual number is probably significantly smaller — perhaps between two and 12, NASA officials said today.
Gaia launched in December of 2013 to create an ultraprecise 3D map of the Milky Way. So far, this map includes position information for about 1.7 billion stars and distance data for about 1.3 billion stars, according to NASA officials. Gaia’s observations suggest that some of the Kepler host stars are brighter and bigger than previously believed, the officials added. Planets orbiting such stars are therefore likely larger and hotter than previously thought.
Being hotter and larger, the habitable zone for these stars shifts outward, placing the exoEarth’s outside the habitable zone.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Worlds without end: The number of candidate exo-Earths identified by Kepler has now been reduced based on data from Europe’s Gaia telescope.
To date, NASA’s prolific Kepler space telescope has discovered about 30 roughly Earth-size exoplanets in their host stars’ “habitable zone” — the range of orbital distances at which liquid water can likely exist on a world’s surface.
Or so researchers had thought. New observations by the European Space Agency’s (ESA) Gaia spacecraft suggest that the actual number is probably significantly smaller — perhaps between two and 12, NASA officials said today.
Gaia launched in December of 2013 to create an ultraprecise 3D map of the Milky Way. So far, this map includes position information for about 1.7 billion stars and distance data for about 1.3 billion stars, according to NASA officials. Gaia’s observations suggest that some of the Kepler host stars are brighter and bigger than previously believed, the officials added. Planets orbiting such stars are therefore likely larger and hotter than previously thought.
Being hotter and larger, the habitable zone for these stars shifts outward, placing the exoEarth’s outside the habitable zone.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
However, how many planets that were previously thought to be too far and cool for life are now in the habitable zone?
Unfortunately, the detection method used by Kepler is less useful for finding planets in farther/longer orbits so this is probably an unknown.
Just for fun while talking about other earth like planets throw this into the calculation, the Zman I am certain will love it.
https://youtu.be/qRqgQ5FD2uI
I had heard of this documentary before but just finished watching it this morning. We have all heard of the phenomenon but its a bit different when you sit down and examine some of the evidence and hear the testimony of the people on the scene. It is by any measure very strange at the minimum.
There is some stuff that goes on on this planet and that is observable and documentable to a certain extent that is just plain inconceivable and very difficult to figure into the reality that we “know” exists. There is plainly something else going on. CIA? Government activities? Why? Does not make sense, but there it all is.
I like to try to know what is what and why things are the way that they are, this throws a big monkey wrench out there.
Think about this: Its much more likely that their are other intelligent life forms on one or more of these exo planets in this galaxy / universe and it is reasonable that they might be 1 million and even 1 billion or more years older and unimaginably more advanced than we are because almost 8 billion years has passed before our solar system and the planet earth even existed in this universe which we exist in which is estimated to be about 13.7 billion years old.
Think about that for a while.
The further the planet is from the star, the more unlikely it will be detected or cause much dimming during it’s transit. A slower orbital time will dim the star so gradually as to be undetectable from the variables.
“Being hotter and larger, the habitable zone for these stars shifts outward, placing the exoEarth’s outside the habitable zone.”
I find it incredible that they think that they can judge what alien life would find acceptable for their “Alien” life form.
They can, of course, only judge by what they know. They can’t be expected to know what they don’t know.
The issue I take is that their assumptions are not based upon hard science. More of an exaggeration of a “sounds” good “let’s go with that idea” instead of looking up the facts of how things work in the “cause and affect” to determine reality over imaginary.
For example, they referred to Earth being in the “Goldilocks zone” the “green zone” and yet, the moon at only 200,000 miles away has an average temperature of 50° below zero!
100° colder than we are. Even though our atmosphere withholds 150° (Out of 250°) from ever reaching the ground.
Article refers to Venus as an example of a runaway greenhouse. Having an average temperature of 860°, because it’s too close to the sun, while ignoring that Mercury is even closer to the sun with the maximum temperature of 800° and an average temperature of less than 200°.
Yes, mercury is much colder than Venus.
Quite literally, the only planets that are not too hot for life in our solar system is earth and Mars. (Pluto gets an honorable mention)
Because heat is largely a function of air pressure (all heat is friction) it is not relevant where the planets position is near a star. It is relevant for photosynthesis which requires plentiful sunlight. (Some life does not require sunlight to grow)
Something for you all to chew on…
Max:
What are the implications for life, even advanced intelligent life, given the fact that 8 billion years had passed before our solar system even existed?
Cotour:
The chances for life are very small considering how many chance “must happens” must coincide with perfect timing.
You’ve heard of examples like walking across a desert and coming across a “pocket watch” keeping perfect time, or a Buick that assembled it self together spontaneously complete with fuel…
It is said that life may have happened when a pool of amino acids was hit by lightning? If so, why did it not die immediately? What would it eat being the first one? What protects it from the elements? With no immune system how did avoid chemical contamination or just getting washed away by rain? All conditions must be perfectly right to even survive, let alone divided self and become multiple organisms. (The chances of this happening go way up when spontaneous crystal growth that occurs in the pattern of the Fibonacci sequence occurs spontaneously in nature)
The beauty of all of this is that it only has to happen “once” somewhere in the universe. After only one intelligent life form grows advanced enough to leave it’s own solar system, it will spread the life through out it’s location which in turn (with self replicating DNA/RNA and improving itself through natural selection as well as the genetic engineering of higher lifeforms) will form intelligent life of its own and spread again.
99% of the advanced life that developed here on earth are extinct, giving way to the most resilient forms that are present now. This all occurred since Pangea half a billion years ago. (There was life before Pangea but we are uncertain because of the complete destruction of our world when it collided with the moon)
This concept of life is very old and has been the subject matter of many books.
Like “Star Trek the next generation” had an episode to explain why so many similar humanoids existed throughout the galaxy answering the great mystery of the original life.
Prometheus also had the same theme of the engineers who’s entire existence was to spread life. Then to destroy it.
I’ve often put forth the oversimplified answer to what god is (not “God”) as an advanced life form like a British TV series time lord “Doctor Who” that live in a dimension formed by a black hole that has slow time relative to our universe. They can exit their time/space anywhere, anytime to perform experiments and surveying the galaxy emptying their sewer tank, like Prometheus, starting new life terraforming young planets in the distant past. Then racing forward a few million years to see what happened… Tweaking the results at selective moments for a predetermined outcome with little effort from precise timing. (for example, the flood of Noah. Observing a natural disaster, help was given to build an ark (a large shelter on the side of a mountain) to preserve the best results of the experiment)(The world being covered with water, think “Ice Age” not “Water-world”)
The Bible refers to them as the nepheline. (The Neflin would procreate with the daughters of men creating the Giants of renown)
Yes, even the Bible has stories of advanced aliens/angels involving them selves in our evolution in the not so distant past.
Like the “up lift Series” there may be extremely old civilization’s out there whos dominant position in the galaxy depend on those whom they help advance. Good sci-fi.
Cotour, I am an optimist, full of hope. As Carl Sagan one said, that if there was no life out there… what a big waste of space…
I exist, therefore I am. I’m not the first, not by a long shot. I am fairly certain that we will not be the last. look out universe… Here we come.
Great response.
Its just the pure numbers to me. We are here as the result of aprox. 4 billion years, and there has been over 8 billion years that have passed before our sun and its planets coalesced.
It seems a lock to me that some form of life is more likely to exist than not as evidenced by our own existence over 4 billion years. And if that life did or does exist and it is able to develop a high intelligence and technology it is highly likely that they are at least millions of years more advanced, maybe even billions of years and there in lies the conundrum, we probably will not be able to detect them at all. Any detection would be at their absolute pleasure and not ours.
How do you detect something that is undetectable unless they allow detection? And this is what leads to all of those great mind experiments in imagination attempting to imagine what the reality might in deed be.
Max,
You wrote: “Because heat is largely a function of air pressure (all heat is friction) it is not relevant where the planets position is near a star.”
Be careful about the cause and effect between temperature (heat) and pressure. It is true that as air descends in our atmosphere, such as a breeze down a mountain, that it increases in temperature as it increases in pressure. However, Pluto demonstrates that the heat of the sun provides the energy and temperature necessary to create the pressure in the first place. As Pluto gets farther from the sun, in its current part of its orbit, heat input is reduced, temperature falls, and the atmosphere condenses onto the surface, reducing Pluto’s atmospheric pressure.
There is some relevance to a planet’s distance from the star.
Clouds also have an effect on a planet’s temperature. Venus is completely covered in clouds, and they help to hold in heat energy. Mars has few clouds, so there is not much to hold in heat; it radiates away to space every night. Earth has some cloudy nights and some cloudless nights; cloudless nights tend to be colder, because the surface can radiate directly to space, but cloudy nights are warmer, because the clouds trap that radiation from escaping to space.
“I find it incredible that they think that they can judge what alien life would find acceptable for their “Alien” life form.
They can, of course, only judge by what they know.”
One of the quests at the SETI Institute is to explore what other life could exist in other environments. Hopefully, this research will increase what we know.
https://www.seti.org/research/Astrobiology
“It is said that life may have happened when a pool of amino acids was hit by lightning? If so, why did it not die immediately? What would it eat being the first one? What protects it from the elements? With no immune system how did avoid chemical contamination or just getting washed away by rain? All conditions must be perfectly right to even survive, let alone divided self and become multiple organisms.”
Most likely, all that lightning created precursor molecules that were capable of eventually turning into self-replicating systems of molecules, such as DNA and protein (combined is a nucleosome). The food would be the other precursor molecules that were floating around.
https://www.youtube.com/watch?v=yqESR7E4b_8 (8 minutes, DNA replication)
Because of various difficulties that you mention, such replication and evolution into better forms of life took quite some time. Eventually they evolved protective shells and the first cells started to form and survive better. It was a couple of billion years before multi-celled organisms formed. Once things got to be that efficient and effective, life really took off and diversified into even better forms.
If life on Earth came from elsewhere, then a process similar to this would have had to happen elsewhere in order to create life in the universe. Since the big bang was not conducive to the existence of atoms, much less molecules, life did not exist at that time and must have formed later.
Are we the first intelligent life in the universe? Maybe. Someone has to be, and maybe that is why we have yet to detect any other signs of intelligent life. This would mean that SETI is futile.