2,000 nearby stars found that see the Earth cross in front of the Sun
Astronomers have identified 2,134 nearby stars that at some point in the past, present, or future are properly positioned along the solar system’s ecliptic so that the Earth can be seen transiting in front of the Sun.
From their paper’s abstract:
[W]e report that 1,715 stars within 100 parsecs from the Sun are in the right position to have spotted life on a transiting Earth since early human civilization (about 5,000 years ago), with an additional 319 stars entering this special vantage point in the next 5,000 years. Among these stars are seven known exoplanet hosts, including Ross-128, which saw Earth transit the Sun in the past, and Teegarden’s Star and Trappist-1, which will start to see it in 29 and 1,642 years, respectively. We found that human-made radio waves have already swept over 75 of the closest stars on our list. [emphasis mine]
I like the detail highlighted. Of the stars that could definitely identify the Earth by transits, 75 are also now close enough to have also heard our radio broadcasts. Should any of those stars also have a sufficiently advanced alien civilization, they could know of our existence. These same stars in turn make for very good targets of study for us to see if there is alien life there.
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 print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
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
Astronomers have identified 2,134 nearby stars that at some point in the past, present, or future are properly positioned along the solar system’s ecliptic so that the Earth can be seen transiting in front of the Sun.
From their paper’s abstract:
[W]e report that 1,715 stars within 100 parsecs from the Sun are in the right position to have spotted life on a transiting Earth since early human civilization (about 5,000 years ago), with an additional 319 stars entering this special vantage point in the next 5,000 years. Among these stars are seven known exoplanet hosts, including Ross-128, which saw Earth transit the Sun in the past, and Teegarden’s Star and Trappist-1, which will start to see it in 29 and 1,642 years, respectively. We found that human-made radio waves have already swept over 75 of the closest stars on our list. [emphasis mine]
I like the detail highlighted. Of the stars that could definitely identify the Earth by transits, 75 are also now close enough to have also heard our radio broadcasts. Should any of those stars also have a sufficiently advanced alien civilization, they could know of our existence. These same stars in turn make for very good targets of study for us to see if there is alien life there.
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 print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. 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
I’ve written a bit before about interstellar communications (or at least my back of the envelope picture of what would be necessary to carry them off.) It isn’t necessarily so that just because our radio signals have reached a given distance that they are detectable at that distance. It seems to me that practical interstellar communication is necessarily a directional affair. The Aricebo message might get somewhere, but anything omnidirectional is going to peter out fast.
My repost of a post of mine on another blog: https://www.amssolarempire.com/Blog/?p=679
Wonder if they can expand to include the transit of Jupiter, which is larger and more noticeable, even though it’s five times further from the sun. It transitions slower, allowing more time to be noticed. Saturn with its rings would be confusing for them as a mystery? Only during its South Pole/N. Pole facing the sun phase.
” Only during its South Pole/N. Pole facing the sun phase.”
That’s Uranus, not Saturn.
1) Alien reaction “Radio? How crude and backwards”
2) ” It isn’t necessarily so that just because our radio signals have reached a given distance that they are detectable at that distance. It seems to me that practical interstellar communication is necessarily a directional affair. The Aricebo message might get somewhere, but anything omnidirectional is going to peter out fast.”
It’s called the inverse square law
Oh boy. The paper bases ONLY the fact that radio transmissions have been going on for ~100 years for the statement that 75 stars have already been in the radio “sphere”. Not a very hard assessment.
They did not even consider anything about the omnidirectional signals these 100 years of signals had (as MadRocketSci stated). This is a real problem. How big does the antenna have to be to receive it? The size of a solar system? Plus there is noise that would baffle the observer.
Directional signals would be more likely to get there, but its hard to have a transmitter signal point long enough to be seen directly at a possible target, and have the target be able to aim a receiver at this signal long enough to hear it. Everything is rotating or revolving so unless receiver and transmitter is in space, pointing is a challenge. So, relying on spurious directional signals seem highly unlikely to be seen or repeatedly seen.
The best thing the report implies is that one might be able to detect atmospheric products indicative of life or civilization. Maybe not definitive, but pretty good.
I admire the innovative thinking that turned the stellar occultation phenomenon on its head. What other opportunities might there be that we have not thought of?
… and we cannot even carry on a decent conversation amongst ourselves without arguing ?
Let alone the local universe?
Pitiful.
Now what is my neighbor doing now ….. ??
Yup, regular leakage of signals will be very weak at interstellar distances. Somewhere I read that military radars are some of few emissions that would be powerful enough to be readily detectable. With both planets rotating and orbiting, and the radar beam presumably narrow, it might not be a periodic and predictable detection window for them. Makes you wonder about some of the unexplained transient signals we’ve detected.
Saturn appears smaller when rings are viewed edge on. Equinox.
WLW’s 500,000 Watt Transmitter
Mason, Ohio (2013)
https://youtu.be/CbHjcwIoTiY
31:43
I look at it this way.
We as a people can now look out and see other planets. Or at least extrapolate them very well if not actually view them yet.
Couldn’t a people a hundred years or so ahead of us tech wise not do the same thing in our direction?
And if so couldn’t they see that this planet is very populated with a very wide variety of life. Someplace quite likely to be habitable to them.
They could at least be getting ready to send a colony fleet right now. Are we going to be ready?
Earth vs the Flying Saucers (1956)
https://youtu.be/NQNvJdqetMA
3:23
Earth vs the Flying Saucers (1956)
https://youtu.be/NQNvJdqetMA
3:23
Pzatchok, , Why should they care about some backwards creatures that still use radio? That’s one assumption of the UFO crowd that I have always found amusing, that as a species we are so endlessly fascinating, that aliens would find us worth traveling to. And that they have have found some way of violating physics as we know it to travel greater than the speed of light. Even traveling at an appreciable fraction of the speed of light is way beyond our capabilities. Just because they may have been around longer doesn’t mean they’ve solved the problem (a Whiggish doctrine of continual improvement in capabilities). We may have to bow eventually to the idea that interstellar travel is impossible. Even interstellar communication remains doubtful. A question-response rate of 150 years? And since we don’t know how to communicate except on the most basic level (“Sit” “Heel”, etc) with other species on our home planet – species that share our line of descent from a common ancestor – why should we be able to communicate to beings totally alien?
“Whiggish – of, relating to, or characterized by a view which holds that history follows a path of inevitable progression and improvement and which judges the past in light of the present” – Merriam-Webster
Col Beausabre
I fully agree with you.
Any species that has the capability of actually getting to us would have the capability of hiding from us in some way.
Why would they find it necessary to fly around in plain sight teasing us?
But also they might not have the capability to come close to the speed of light and at this moment could be building a generation ship with the sole purpose of colonizing this planet. They would not be able to see any advanced industrialization until they get far closer to us and by then they might not be able to turn around.
How would or could a colony ship of 10,000 people with a tech level only a little above our own invade us?
If their tech is too far above ours we stand no chance at all. Turning us into slaves would be our best outcome at that point.
” Turning us into slaves would be our best outcome at that point.”
Remember the sci-fi story when the title of an alien document was decoded,- “To Serve Mankind”
Worldwide relief ensues
Turns out it was a cookbook.
In the Balance
(Worldwar #1)
by Harry Turtledove
Its a pretty good series of Sci-fi books.
Aliens invade during WWII. With just one problem. They didn’t know mankind had entered the industrial age and thought they would only face horse riding speermen.