APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

Post a reply


This question is a means of preventing automated form submissions by spambots.
Smilies
:D :) :ssmile: :( :o :shock: :? 8-) :lol2: :x :P :oops: :cry: :evil: :roll: :wink: :!: :?: :idea: :arrow: :| :mrgreen:
View more smilies

BBCode is ON
[img] is ON
[url] is ON
Smilies are ON

Topic review
   

Expand view Topic review: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by rstevenson » Thu Jun 14, 2018 6:38 pm

Chris Peterson wrote: Mon Jun 11, 2018 9:34 pm
BDanielMayfield wrote: Mon Jun 11, 2018 9:06 pm So, hypothetically, if humanity can finally grow up and learn to intelligently manage this gem of a planet in a sustainable way, then doing even very long range projects to keep the Earth in the slowly shifting sweet spot of the Sun's HZ for as long as possible only makes sense.
We can only grow up by two mechanisms: we can evolve a different brain structure, or we can modify our brain structure using technology. The former is too slow. We'll kill ourselves first (or drive ourselves back to a pretechnological society). The latter could work, and we'll soon have the technical capability. But will we use it?
Oh yes, we'll use it. But will we use it well? Pfffft! When have we ever used technology only well? No doubt we'll find ways to subvert to an appalling degree any such technology -- as well as doing good things with it.

Rob

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by MarkBour » Tue Jun 12, 2018 3:44 pm

BDanielMayfield wrote: Mon Jun 11, 2018 9:40 pm Thanks Mark. Interesting ideas about avoiding "the Y5B problem", but don't forget about the Y4B big event:
The Andromeda–Milky Way collision is a galactic collision predicted to occur in about 4 billion years between two galaxies in the Local Group—the Milky Way (which contains the Solar System and Earth) and the Andromeda Galaxy.[1][2][3][4] The stars involved are sufficiently far apart that it is improbable that any of them will individually collide.[5] Some stars will be ejected from the resulting galaxy, nicknamed Milkomeda or Milkdromeda.
Lots of new stars will be formed by this mega merger prior to the Sun's exodus from the main sequence. No one can tell what new opportunities this might open up. This could even provide the Y4B solution. :ssmile:

Bruce
Ah, definitely something else to consider! I'm going to need a bigger computer. No, wait. It's the computers that are going to kill us off. First thing they'll do is "erase" our backups.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by MarkBour » Tue Jun 12, 2018 3:34 pm

BDanielMayfield wrote: Mon Jun 11, 2018 9:06 pm
Chris Peterson wrote: Mon Jun 11, 2018 4:27 pm
soynelson wrote: Mon Jun 11, 2018 1:47 am Hola Chris.
Justamente, como tú dices eso es un promedio, a lo que hay que agregar que el Homo Sapiens tiene la cualidad de incidir activamente en el ambiente y modificarlo en su beneficio. De no tener esa condición, no hubiera evolucionado hasta aquí y se hubiera extinguido tempranamente como sus antecesores homínidos, debido a su relativa debilidad física frente a sus depredadores naturales y las hostilidades del entorno físico.
Por lo que existe una duda razonable de que la especie continúe sobreviviendo indefinidamente superándose a sí mismo, a las adversidades y creando progresivamente condiciones superiores para su desarrollo.
De modo que la información llegará sencillamente trasmitida y enriquecida de generación en generación... salvo que un evento cataclismo nos borre de un golpe.
I'd love to see a translation of soynelson's comment.
Google Translate, Spanish -> English, gives:
Hello Chris.
Just as you say that is an average, to which it must be added that Homo Sapiens has the quality to actively influence the environment and modify it to its benefit. If it did not have that condition, it would not have evolved until now and would have been extinguished early like its hominid ancestors, due to its relative physical weakness in front of its natural predators and the hostilities of the physical environment.
So there is a reasonable doubt that the species continues to survive indefinitely surpassing itself, adversities and progressively creating superior conditions for its development.
So the information will arrive simply transmitted and enriched from generation to generation ... unless a cataclysm event erases us in one fell swoop.
Chris' reply:
It's certainly true that our existence as a highly cultural species sets us apart from all other extant species, and most likely all other species that have ever existed on Earth. We are also the only technological species. My view is that technological species (at least, ones with an evolutionary history like humans) are inherently unstable. I anticipate we will self-destruct, probably not too far in the future, and end up a fairly short-lived species. That seems far more likely than any extinction causing natural catastrophe.
Although I'm ultimately an optimist, I agree with Chris' opinion that the world is headed toward a massive man made collapse. I don't think this will terminate the whole human race however. If survivors and their descendants can eventually learn from the mistakes of the past the long term prospects for humanity could be much longer than the admittedly realistic pessimistic viewpoint predicts.

So, hypothetically, if humanity can finally grow up and learn to intelligently manage this gem of a planet in a sustainable way, then doing even very long range projects to keep the Earth in the slowly shifting sweet spot of the Sun's HZ for as long as possible only makes sense.

Bruce
One of humanity's ideas for how to cheat death is in the creation of what amount to "backups". Will this idea alter the outcome?

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by BDanielMayfield » Mon Jun 11, 2018 9:40 pm

MarkBour wrote: Mon Jun 11, 2018 4:18 pm
BDanielMayfield wrote: Sun Jun 10, 2018 1:07 pm
MarkBour wrote: Sun Jun 10, 2018 8:42 am I think the Y5B problem is going to be a lot worse than the Y2K problem.
Yeah, that's a tough one, but at least a solution to the Y1B problem has already been worked out:
Astronomical engineering: a strategy for modifying planetary orbits

D. G. Korycansky, Gregory Laughlin, Fred C. Adams
(Submitted on 7 Feb 2001)
The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this paper, we explore the feasibility of engineering such a migration over a long time period. The basic mechanism uses gravitational assists to (in effect) transfer orbital energy from Jupiter to the Earth, and thereby enlarges the orbital radius of Earth. This transfer is accomplished by a suitable intermediate body, either a Kuiper Belt object or a main belt asteroid. The object first encounters Earth during an inward pass on its initial highly elliptical orbit of large (~ 300 AU) semimajor axis. The encounter transfers energy from the object to the Earth in standard gravity-assist fashion by passing close to the leading limb of the planet. The resulting outbound trajectory of the object must cross the orbit of Jupiter; with proper timing, the outbound object encounters Jupiter and picks up the energy it lost to Earth. With small corrections to the trajectory, or additional planetary encounters (e.g., with Saturn), the object can repeat this process over many encounters. To maintain its present flux of solar energy, the Earth must experience roughly one encounter every 6000 years (for an object mass of 1E22 g). We develop the details of this scheme and discuss its ramifications.
Thanks for sharing that, Bruce, it is a beautiful idea. I like getting closer to Jupiter for this one, because it makes it easier for my idea for the Y5B problem. In that idea, you need two gas giants and you need the Earth to get close to them and the 3 bodies to be gravitationally bound together. Then use one gas giant for propulsion and the other for light & heat, while the three bodies are made to migrate to another star.

My other reaction to this idea of Korycansky, Laughlin, and Adams that you shared, is that it gives a possible clue in the hunt for intelligent life. It might be helpful to look for planetary systems where the central star is over 5 billion years old and the natural order of planetary distributions has been altered. I don't think we have enough information about the natural possibilities in solar system formations yet to know what would be a sign that "something was not natural", but perhaps one day we will. For instance, suppose we did cause the Earth to migrate out past the orbit of Mars. Would a clever species looking at our solar system know that this was not where she began or belonged? Or are the possibilities in natural development just too wide open to ever say that something was altered? (Short of finding some utterly fantastic structure.)
Thanks Mark. Interesting ideas about avoiding "the Y5B problem", but don't forget about the Y4B big event:
The Andromeda–Milky Way collision is a galactic collision predicted to occur in about 4 billion years between two galaxies in the Local Group—the Milky Way (which contains the Solar System and Earth) and the Andromeda Galaxy.[1][2][3][4] The stars involved are sufficiently far apart that it is improbable that any of them will individually collide.[5] Some stars will be ejected from the resulting galaxy, nicknamed Milkomeda or Milkdromeda.
Lots of new stars will be formed by this mega merger prior to the Sun's exodus from the main sequence. No one can tell what new opportunities this might open up. This could even provide the Y4B solution. :ssmile:

Bruce

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Chris Peterson » Mon Jun 11, 2018 9:34 pm

BDanielMayfield wrote: Mon Jun 11, 2018 9:06 pm So, hypothetically, if humanity can finally grow up and learn to intelligently manage this gem of a planet in a sustainable way, then doing even very long range projects to keep the Earth in the slowly shifting sweet spot of the Sun's HZ for as long as possible only makes sense.
We can only grow up by two mechanisms: we can evolve a different brain structure, or we can modify our brain structure using technology. The former is too slow. We'll kill ourselves first (or drive ourselves back to a pretechnological society). The latter could work, and we'll soon have the technical capability. But will we use it?

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by BDanielMayfield » Mon Jun 11, 2018 9:06 pm

Chris Peterson wrote: Mon Jun 11, 2018 4:27 pm
soynelson wrote: Mon Jun 11, 2018 1:47 am Hola Chris.
Justamente, como tú dices eso es un promedio, a lo que hay que agregar que el Homo Sapiens tiene la cualidad de incidir activamente en el ambiente y modificarlo en su beneficio. De no tener esa condición, no hubiera evolucionado hasta aquí y se hubiera extinguido tempranamente como sus antecesores homínidos, debido a su relativa debilidad física frente a sus depredadores naturales y las hostilidades del entorno físico.
Por lo que existe una duda razonable de que la especie continúe sobreviviendo indefinidamente superándose a sí mismo, a las adversidades y creando progresivamente condiciones superiores para su desarrollo.
De modo que la información llegará sencillamente trasmitida y enriquecida de generación en generación... salvo que un evento cataclismo nos borre de un golpe.
I'd love to see a translation of soynelson's comment. Chris' reply:
It's certainly true that our existence as a highly cultural species sets us apart from all other extant species, and most likely all other species that have ever existed on Earth. We are also the only technological species. My view is that technological species (at least, ones with an evolutionary history like humans) are inherently unstable. I anticipate we will self-destruct, probably not too far in the future, and end up a fairly short-lived species. That seems far more likely than any extinction causing natural catastrophe.
Although I'm ultimately an optimist, I agree with Chris' opinion that the world is headed toward a massive man made collapse. I don't think this will terminate the whole human race however. If survivors and their descendants can eventually learn from the mistakes of the past the long term prospects for humanity could be much longer than the admittedly realistic pessimistic viewpoint predicts.

So, hypothetically, if humanity can finally grow up and learn to intelligently manage this gem of a planet in a sustainable way, then doing even very long range projects to keep the Earth in the slowly shifting sweet spot of the Sun's HZ for as long as possible only makes sense.

Bruce

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by neufer » Mon Jun 11, 2018 7:03 pm

Click to play embedded YouTube video.
.
.
Chris Peterson wrote: Mon Jun 11, 2018 4:27 pm
It's certainly true that our existence as a highly cultural species sets us apart from all other extant species, and most likely all other species that have ever existed on Earth. We are also the only technological species. My view is that technological species (at least, ones with an evolutionary history like humans) are inherently unstable. I anticipate we will self-destruct, probably not too far in the future, and end up a fairly short-lived species. That seems far more likely than any extinction causing natural catastrophe.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Chris Peterson » Mon Jun 11, 2018 4:27 pm

soynelson wrote: Mon Jun 11, 2018 1:47 am Hola Chris.
Justamente, como tú dices eso es un promedio, a lo que hay que agregar que el Homo Sapiens tiene la cualidad de incidir activamente en el ambiente y modificarlo en su beneficio. De no tener esa condición, no hubiera evolucionado hasta aquí y se hubiera extinguido tempranamente como sus antecesores homínidos, debido a su relativa debilidad física frente a sus depredadores naturales y las hostilidades del entorno físico.
Por lo que existe una duda razonable de que la especie continúe sobreviviendo indefinidamente superándose a sí mismo, a las adversidades y creando progresivamente condiciones superiores para su desarrollo.
De modo que la información llegará sencillamente trasmitida y enriquecida de generación en generación... salvo que un evento cataclismo nos borre de un golpe.
It's certainly true that our existence as a highly cultural species sets us apart from all other extant species, and most likely all other species that have ever existed on Earth. We are also the only technological species. My view is that technological species (at least, ones with an evolutionary history like humans) are inherently unstable. I anticipate we will self-destruct, probably not too far in the future, and end up a fairly short-lived species. That seems far more likely than any extinction causing natural catastrophe.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by MarkBour » Mon Jun 11, 2018 4:18 pm

BDanielMayfield wrote: Sun Jun 10, 2018 1:07 pm
MarkBour wrote: Sun Jun 10, 2018 8:42 am I think the Y5B problem is going to be a lot worse than the Y2K problem.
Yeah, that's a tough one, but at least a solution to the Y1B problem has already been worked out:
Astronomical engineering: a strategy for modifying planetary orbits

D. G. Korycansky, Gregory Laughlin, Fred C. Adams
(Submitted on 7 Feb 2001)
The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this paper, we explore the feasibility of engineering such a migration over a long time period. The basic mechanism uses gravitational assists to (in effect) transfer orbital energy from Jupiter to the Earth, and thereby enlarges the orbital radius of Earth. This transfer is accomplished by a suitable intermediate body, either a Kuiper Belt object or a main belt asteroid. The object first encounters Earth during an inward pass on its initial highly elliptical orbit of large (~ 300 AU) semimajor axis. The encounter transfers energy from the object to the Earth in standard gravity-assist fashion by passing close to the leading limb of the planet. The resulting outbound trajectory of the object must cross the orbit of Jupiter; with proper timing, the outbound object encounters Jupiter and picks up the energy it lost to Earth. With small corrections to the trajectory, or additional planetary encounters (e.g., with Saturn), the object can repeat this process over many encounters. To maintain its present flux of solar energy, the Earth must experience roughly one encounter every 6000 years (for an object mass of 1E22 g). We develop the details of this scheme and discuss its ramifications.
Thanks for sharing that, Bruce, it is a beautiful idea. I like getting closer to Jupiter for this one, because it makes it easier for my idea for the Y5B problem. In that idea, you need two gas giants and you need the Earth to get close to them and the 3 bodies to be gravitationally bound together. Then use one gas giant for propulsion and the other for light & heat, while the three bodies are made to migrate to another star.

My other reaction to this idea of Korycansky, Laughlin, and Adams that you shared, is that it gives a possible clue in the hunt for intelligent life. It might be helpful to look for planetary systems where the central star is over 5 billion years old and the natural order of planetary distributions has been altered. I don't think we have enough information about the natural possibilities in solar system formations yet to know what would be a sign that "something was not natural", but perhaps one day we will. For instance, suppose we did cause the Earth to migrate out past the orbit of Mars. Would a clever species looking at our solar system know that this was not where she began or belonged? Or are the possibilities in natural development just too wide open to ever say that something was altered? (Short of finding some utterly fantastic structure.)

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by soynelson » Mon Jun 11, 2018 1:47 am

Chris Peterson wrote: Sun Jun 10, 2018 1:20 pm
BDanielMayfield wrote: Sun Jun 10, 2018 1:07 pm
MarkBour wrote: Sun Jun 10, 2018 8:42 am I think the Y5B problem is going to be a lot worse than the Y2K problem.
Yeah, that's a tough one, but at least a solution to the Y1B problem has already been worked out:
Astronomical engineering: a strategy for modifying planetary orbits

D. G. Korycansky, Gregory Laughlin, Fred C. Adams
(Submitted on 7 Feb 2001)
The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this paper, we explore the feasibility of engineering such a migration over a long time period. The basic mechanism uses gravitational assists to (in effect) transfer orbital energy from Jupiter to the Earth, and thereby enlarges the orbital radius of Earth. This transfer is accomplished by a suitable intermediate body, either a Kuiper Belt object or a main belt asteroid. The object first encounters Earth during an inward pass on its initial highly elliptical orbit of large (~ 300 AU) semimajor axis. The encounter transfers energy from the object to the Earth in standard gravity-assist fashion by passing close to the leading limb of the planet. The resulting outbound trajectory of the object must cross the orbit of Jupiter; with proper timing, the outbound object encounters Jupiter and picks up the energy it lost to Earth. With small corrections to the trajectory, or additional planetary encounters (e.g., with Saturn), the object can repeat this process over many encounters. To maintain its present flux of solar energy, the Earth must experience roughly one encounter every 6000 years (for an object mass of 1E22 g). We develop the details of this scheme and discuss its ramifications.
However, since on average species exist for only a few hundred thousand years, I wonder how we can transmit this information to whatever technological species is present on Earth (if any) when this becomes a relevant issue?
Hola Chris.
Justamente, como tú dices eso es un promedio, a lo que hay que agregar que el Homo Sapiens tiene la cualidad de incidir activamente en el ambiente y modificarlo en su beneficio. De no tener esa condición, no hubiera evolucionado hasta aquí y se hubiera extinguido tempranamente como sus antecesores homínidos, debido a su relativa debilidad física frente a sus depredadores naturales y las hostilidades del entorno físico.
Por lo que existe una duda razonable de que la especie continúe sobreviviendo indefinidamente superándose a sí mismo, a las adversidades y creando progresivamente condiciones superiores para su desarrollo.
De modo que la información llegará sencillamente trasmitida y enriquecida de generación en generación... salvo que un evento cataclismo nos borre de un golpe.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Ann » Sun Jun 10, 2018 10:58 pm

Chris Peterson wrote: Sun Jun 10, 2018 4:35 pm
sillyworm2 wrote: Sun Jun 10, 2018 4:29 pm Just sad to know that there WILL be an end someday.
Why? It is an ending which gives meaning to what comes before.
Many years ago, I read a sci-fi novella whose name I have totally forgotten, where science had cured all diseases and managed to prevent the human body from aging. So it had become possible for people to live indefinitely, or at least until the Earth or the Universe became totally inhospitable.

But in this world, people could still die from accidents or from attacks. This had led to everyone being totally terrified of dying, just because eternal life was a possibility but not a given thing. People barricaded themselves in their fortress-like homes and viewed everyone else with the utmost fear and suspicion. It was quite a fascinating premise (and no, I don't remember how the story ended).

But it struck me, after I had read at least the beginning of it (I may or may not have finished it), that most people really live without being totally hung up on death, just because we know that death is an absolute certainty and we have to live life while we are alive, in the here and now.

Ann

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by neufer » Sun Jun 10, 2018 5:59 pm

Chris Peterson wrote: Sun Jun 10, 2018 4:35 pm
sillyworm2 wrote: Sun Jun 10, 2018 4:29 pm
Just sad to know that there WILL be an end someday.
Why? It is an ending which gives meaning to what comes before.
https://i.pinimg.com/originals/76/52/f9 ... f88a5f.jpg

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Chris Peterson » Sun Jun 10, 2018 4:35 pm

sillyworm2 wrote: Sun Jun 10, 2018 4:29 pm Just sad to know that there WILL be an end someday.
Why? It is an ending which gives meaning to what comes before.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by sillyworm2 » Sun Jun 10, 2018 4:29 pm

Just sad to know that there WILL be an end someday.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Sa Ji Tario » Sun Jun 10, 2018 2:08 pm

What is seen in the Cat's Eye Nebula is a symmetric process of EMC and modified by the binary wind particles. In addition, a few rarefactions and densifications of the environment of the same materials that travel with the pair in its celestial orbit forming shells well visible in the image and auction a radial emissions of plasma that accentuate the beauty of the whole in the vicinity. If we observe a radius several thousand times greater, we will see a chaos of materials that lose speed and that resemble an octopus hunting with its body deployed

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Chris Peterson » Sun Jun 10, 2018 1:20 pm

BDanielMayfield wrote: Sun Jun 10, 2018 1:07 pm
MarkBour wrote: Sun Jun 10, 2018 8:42 am I think the Y5B problem is going to be a lot worse than the Y2K problem.
Yeah, that's a tough one, but at least a solution to the Y1B problem has already been worked out:
Astronomical engineering: a strategy for modifying planetary orbits

D. G. Korycansky, Gregory Laughlin, Fred C. Adams
(Submitted on 7 Feb 2001)
The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this paper, we explore the feasibility of engineering such a migration over a long time period. The basic mechanism uses gravitational assists to (in effect) transfer orbital energy from Jupiter to the Earth, and thereby enlarges the orbital radius of Earth. This transfer is accomplished by a suitable intermediate body, either a Kuiper Belt object or a main belt asteroid. The object first encounters Earth during an inward pass on its initial highly elliptical orbit of large (~ 300 AU) semimajor axis. The encounter transfers energy from the object to the Earth in standard gravity-assist fashion by passing close to the leading limb of the planet. The resulting outbound trajectory of the object must cross the orbit of Jupiter; with proper timing, the outbound object encounters Jupiter and picks up the energy it lost to Earth. With small corrections to the trajectory, or additional planetary encounters (e.g., with Saturn), the object can repeat this process over many encounters. To maintain its present flux of solar energy, the Earth must experience roughly one encounter every 6000 years (for an object mass of 1E22 g). We develop the details of this scheme and discuss its ramifications.
However, since on average species exist for only a few hundred thousand years, I wonder how we can transmit this information to whatever technological species is present on Earth (if any) when this becomes a relevant issue?

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by BDanielMayfield » Sun Jun 10, 2018 1:07 pm

MarkBour wrote: Sun Jun 10, 2018 8:42 am I think the Y5B problem is going to be a lot worse than the Y2K problem.
Yeah, that's a tough one, but at least a solution to the Y1B problem has already been worked out:
Astronomical engineering: a strategy for modifying planetary orbits

D. G. Korycansky, Gregory Laughlin, Fred C. Adams
(Submitted on 7 Feb 2001)
The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this paper, we explore the feasibility of engineering such a migration over a long time period. The basic mechanism uses gravitational assists to (in effect) transfer orbital energy from Jupiter to the Earth, and thereby enlarges the orbital radius of Earth. This transfer is accomplished by a suitable intermediate body, either a Kuiper Belt object or a main belt asteroid. The object first encounters Earth during an inward pass on its initial highly elliptical orbit of large (~ 300 AU) semimajor axis. The encounter transfers energy from the object to the Earth in standard gravity-assist fashion by passing close to the leading limb of the planet. The resulting outbound trajectory of the object must cross the orbit of Jupiter; with proper timing, the outbound object encounters Jupiter and picks up the energy it lost to Earth. With small corrections to the trajectory, or additional planetary encounters (e.g., with Saturn), the object can repeat this process over many encounters. To maintain its present flux of solar energy, the Earth must experience roughly one encounter every 6000 years (for an object mass of 1E22 g). We develop the details of this scheme and discuss its ramifications.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by MarkBour » Sun Jun 10, 2018 8:42 am

I think the Y5B problem is going to be a lot worse than the Y2K problem.

Re: APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by Boomer12k » Sun Jun 10, 2018 7:32 am

Very nice Hubble Image...my Cat's Eye is fuzzy, I did not have good focus, and I think the color saturation was set too high in a lot of my earlier work...about the best I could get, even with my 10" Meade LX 200 scope.

:---[===] *
Attachments
cat eye_1.jpg

APOD: The Cat's Eye Nebula from Hubble (2018 Jun 10)

by APOD Robot » Sun Jun 10, 2018 4:08 am

Image The Cat's Eye Nebula from Hubble

Explanation: To some, it may look like a cat's eye. The alluring Cat's Eye nebula, however, lies three thousand light-years from Earth across interstellar space. A classic planetary nebula, the Cat's Eye (NGC 6543) represents a final, brief yet glorious phase in the life of a sun-like star. This nebula's dying central star may have produced the simple, outer pattern of dusty concentric shells by shrugging off outer layers in a series of regular convulsions. But the formation of the beautiful, more complex inner structures is not well understood. Seen so clearly in this digitally sharpened Hubble Space Telescope image, the truly cosmic eye is over half a light-year across. Of course, gazing into this Cat's Eye, astronomers may well be seeing the fate of our sun, destined to enter its own planetary nebula phase of evolution ... in about 5 billion years.

<< Previous APOD This Day in APOD Next APOD >>

Top