Key advance in solar sails for the search of extraterrestrial life.

[Exoscientist]

The Parker Solar Probe recently survived its closest flyby of the Sun at only 0.04 AU. 

 This gives confidence that the proposal to achieve high speed of a solar sail using a close flyby of the Sun using the ultralight, but high temperature material aerographite can work:

Interstellar Sails: A New Analysis of Aerographite
by Paul Gilster | Sep 27, 2023 | Sail Concepts |
https://www.centauri-dreams.org/2023/09/27/interstellar-sails-a-new-analysis-of-aerographite

Such a solar sail could reach a speed of 2%c, 6,000 km/s, using this close flyby. At this speed it could reach the solar gravitational lens(SGL) at 550 AU in only 6 months, and ‘Oumuamua in only 11 days(!)

The implications are stunning. Aerographite is an existing material. Then this means we currently have this capability.

Telescopes placed at the solar gravitational lens(SGL) would have the ability to amplify the images of an Earth-sized exoplanet by 100 billion times. It could resolve continent-sized features on such a planet. 

‘Oumuamua is an interstellar object whose unusual motions led some to speculate it could be of artificial origin.

Then we now have the capability to directly observe Earth-sized exoplanets in other star systems and to determine features on an interstellar object that came into our solar system which may have been artificially produced.

  Bob Clark

Edited December 28, 2024 by Exoscientist

[darthgently]

1 hour ago, Exoscientist said:

The Parker Solar Probe recently survived its closest flyby of the Sun at only 0.04 AU. 

 This gives confidence that the proposal to achieve high speed of a solar sail using a close flyby of the Sun using the ultralight, but high temperature material aerographite can work:

Interstellar Sails: A New Analysis of Aerographite
by Paul Gilster | Sep 27, 2023 | Sail Concepts |
https://www.centauri-dreams.org/2023/09/27/interstellar-sails-a-new-analysis-of-aerographite

Such a solar sail could reach a speed of 2%c, 6,000 km/s, using this close flyby. At this speed it could reach the solar gravitational lens(SGL) at 550 AU in only 6 months, and ‘Oumuamua in only 11 days(!)

The implications are stunning. Aerographite is an existing material. Then this means we currently have this capability.

Telescopes placed at the solar gravitational lens(SGL) would have the ability to amplify the images of an Earth-sized exoplanet by 100 billion times. It could resolve continent-sized features on such a planet. 

‘Oumuamua is an interstellar object whose unusual motions led some to speculate it could be of artificial origin.

Then we now have the capability to directly observe Earth-sized exoplanets in other star systems and to determine features on an interstellar object that came into our solar system which may have been artificially produced.

  Bob Clark

Imagine the “refocus” time to move the receivers of a grav lens scope around in the Oort Cloud.  Circular orbital period out there is on the order of 6.3 x 10^8 years.  Nanodegrees per day.

What we’d probably want to do is put millions or billions of cheap sats in a constellation of spherical coverage and then use signal processing technique to determine what is in focus without having to alter any orbits (all sats auto scan around the rim of the sun with a blind blocking the sun?)

What is the power source for these sats where the sunlight is near nothing?  Multiply by a million or a billion.  But I think it is still worth thinking about as there could come a day where all this would be no huge stretch

[Shpaget]

How do you slow down from 2% c and not overshoot your destination?

Edited December 29, 2024 by Shpaget

[darthgently]

32 minutes ago, Shpaget said:

How do you slow down from 2% c and not overshoot your destination?

Can’t use the sail to slow down so it seems like it would only be useful for one shot probes going to the Oort and beyond.

[JoeSchmuckatelli]

11 hours ago, Exoscientist said:

The Parker Solar Probe recently survived its closest flyby of the Sun at only 0.04 AU. 

 This gives confidence that the proposal to achieve high speed of a solar sail using a close flyby of the Sun using the ultralight, but high temperature material aerographite can work:

These two ideas do not match up.

The PSP is dedicatedly built for the expected environment - with considerable shielding.  Just because it has done what it has done does not mean something else with ultralight construction can, with any confidence.

Just sayin.

[magnemoe]

10 hours ago, Shpaget said:

How do you slow down from 2% c and not overshoot your destination?,

You don't with this technology. You might take some incredibly photos passing the lens point photos who show far more than an pale blue dot. 
 

[Exoscientist]

On 12/29/2024 at 12:47 AM, Shpaget said:

How do you slow down from 2% c and not overshoot your destination?

It might be Robert L Forwards idea of reflecting back the light from the main sail to a smaller sail would allow you to slow down the smaller sail to stop at the destination.

 A problem though is Dr. Forward intended this for the case of laser propulsion where the reflected light could be focused onto the receiving sail. This might not work for the non coherent light from the Sun.

 However, actually for the solar gravitational lens it still works as long as you are on a line extending out from the SGL so you may not need to slow down for that case.

 

  Bob Clark

Edited December 31, 2024 by Exoscientist

[Superfluous J]

On 12/29/2024 at 12:47 AM, Shpaget said:

How do you slow down from 2% c and not overshoot your destination?

The same way many probes over the past decades have slowed down after reaching their destination.

You don't.

Edited December 31, 2024 by Superfluous J

[JoeSchmuckatelli]

9 minutes ago, Superfluous J said:

 

You don't

Welllll... 

There is the time honored method of impacting the target

Jus sayin 

[darthgently]

1 hour ago, JoeSchmuckatelli said:

Welllll... 

There is the time honored method of impacting the target

Jus sayin 

We should put an Apple ID tag on every belt and Oort object to keep track of them.  Impact justified

[AckSed]

2 hours ago, JoeSchmuckatelli said:

Welllll... 

There is the time honored method of impacting the target

Jus' sayin'.

Impacting at 2% c, though... that's when solid matter stops being matter and begins to approach plasma. Maybe even fusion fuel.

No idea how you make a crasher stage for that.

But to bring it back, the key here is to send a train of the presumably mass-produced probes, passing through the focal point one after the other.

[darthgently]

1 hour ago, AckSed said:

Impacting at 2% c, though... that's when solid matter stops being matter and begins to approach plasma. Maybe even fusion fuel.

No idea how you make a crasher stage for that.

But to bring it back, the key here is to send a train of the presumably mass-produced probes, passing through the focal point one after the other.

At 2% c the post processing would have to adjust for the additional red shift quite a bit

[Nuke]

9 hours ago, JoeSchmuckatelli said:

Welllll... 

There is the time honored method of impacting the target

Jus sayin 

i wonder if we could hack evolution. sent a very large number of bio engineered tardigrade-esque critters implanted with a dna repository of every life form on earth via a gene drive. after a certain number of generations a rapid evolution program executes. mutations are replaced with planned genetic insertions in the right order to create an entire ecosystem. even if steps are needed say, convert the atmosphere to oxygen, you can just evolve the proper organism to do the job (you would have a number of bio-engineered terraforming germs in the tool box). you do need a robust seed organism though, and maybe more than one type to account for a wide range of extremities. you dont even have to go there, some point in the distant future a human civilization will exist on that target. if you can also somehow also encode the sum of human knowledge in the genome, so much the better.

[darthgently]

5 hours ago, Nuke said:

i wonder if we could hack evolution. sent a very large number of bio engineered tardigrade-esque critters implanted with a dna repository of every life form on earth via a gene drive. after a certain number of generations a rapid evolution program executes. mutations are replaced with planned genetic insertions in the right order to create an entire ecosystem. even if steps are needed say, convert the atmosphere to oxygen, you can just evolve the proper organism to do the job (you would have a number of bio-engineered terraforming germs in the tool box). you do need a robust seed organism though, and maybe more than one type to account for a wide range of extremities. you dont even have to go there, some point in the distant future a human civilization will exist on that target. if you can also somehow also encode the sum of human knowledge in the genome, so much the better.

A Star Trek Genesis Bomb

[Nuke]

1 hour ago, darthgently said:

A Star Trek Genesis Bomb

i guess. but its more like a cannon than a bomb. a great shotgun in space really. its sort of like shooting birdshot at a moose.

[darthgently]

54 minutes ago, Nuke said:

i guess. but its more like a cannon than a bomb. a great shotgun in space really. its sort of like shooting birdshot at a moose.

I was just making a movie reference.  But you bring up a good point, I think they called it the Genesis Device in the movie and the bad guys wanted to use it as a bomb of sorts on an already living world.  Iirc, been a very long since I watched it.  I recall it worked on a much more fundamental level than tardigrades.

 Lichens are also a really good candidate and are a favored biome for tardigrades so nice dovetail

Edited January 1 by darthgently

[Nuke]

i was origninally thinking protomolecule. but i think the genesis device is more accurate. especially the fine line between being a terraforming tool and a potential bioweapon if used on an already inhabited world. it could have a failsafe implemented that will halt the rapid evolution process if it detects a functional biosphere. it is something you want to shotgun around though. you might have a success rate of 1 in 100. so hit em all. and converting a biosphere is something that will take almost as long as the transit time, so instant results are not expected. but millions of years of seeding colonies, followed by those colonies sending out their own seed colonies, your interstellar war might have humans (or some offshoot) fighting eachother.

[Iapetus7342]

On 12/31/2024 at 11:22 PM, JoeSchmuckatelli said:

Welllll... 

There is the time honored method of impacting the target

Jus sayin 

B O I

The probe is going 2% Lightspeed, if it hits something then it's going to be vapourised on impact

[darthgently]

2 hours ago, Iapetus7342 said:

B O I

The probe is going 2% Lightspeed, if it hits something then it's going to be vapourised on impact

Triple layers of NASA grade Captan™️ based bubble wrap should do the trick

[JoeSchmuckatelli]

4 hours ago, Iapetus7342 said:

B O I

The probe is going 2% Lightspeed, if it hits something then it's going to be vapourised on impact

Yep. 

 

https://www.google.com/search?q=What+would+happen+if+a+2000+pound+probe+at+2%+light+speed+hits+planet&client=ms-android-samsung-ss&sca_esv=a11fe0c8493c2c3e&ei=MVt3Z6nmEdWXwbkPwqDRyQk&oq=What+would+happen+if+a+2000+pound+probe+at+2%+light+speed+hits+planet&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIkVXaGF0IHdvdWxkIGhhcHBlbiBpZiBhIDIwMDAgcG91bmQgcHJvYmUgYXQgMiUgbGlnaHQgc3BlZWQgaGl0cyBwbGFuZXRI7PQBUIxWWO3uAXABeAGQAQKYAaYCoAG1HaoBBjAuMTYuNrgBA8gBAPgBAZgCB6AC7QfCAgoQABiwAxjWBBhHwgIEEB4YCsICBBAhGAqYAwCIBgGQBgiSBwUxLjUuMaAH-SA&sclient=mobile-gws-wiz-serp

See nice short form link to AI 'answer', which to my knuckle dragging jar head brain equates to 'stopping' the probe 

[darthgently]

40 minutes ago, JoeSchmuckatelli said:

equates to 'stopping' the probe 

I ran your question by grok and it agrees:

(I wish this forum formatted the eqns as nice as they look before the copy pasta operation)

Spoiler

If a 2000-pound probe traveling at 2% of the speed of light (approximately 6,000 km/s or 3,728 miles per second) were to hit a planet, here are some potential outcomes:

- **Impact Energy:** The kinetic energy of the probe would be immense. Using the formula for kinetic energy, \(E = \frac{1}{2}mv^2\), where \(m\) is mass and \(v\) is velocity, the energy would be:

  \[
  E = \frac{1}{2} \times 907.185 \text{ kg} \times (6000000 \text{ m/s})^2 \approx 1.63 \times 10^{16} \text{ J}
  \]

  This energy release is equivalent to about 3.9 megatons of TNT, far exceeding the energy yield of most nuclear warheads.

- **Crater Formation:** The probe would create a significant impact crater. The exact size would depend on various factors like the composition of the planet's surface, but it would likely be in the range of kilometers in diameter. This impact would vaporize a large amount of material at the point of contact, sending shockwaves through the planet's crust.

- **Atmospheric Effects:** If the planet has an atmosphere, the probe would likely create a massive shockwave, potentially leading to a fireball, atmospheric heating, and possibly altering atmospheric chemistry. There could be significant atmospheric loss if the impact were strong enough.

- **Seismic Waves:** The impact would generate seismic waves, potentially causing quakes or even tsunamis if the impact site were near or under water.

- **Global Consequences:** Depending on the planet's size and composition, this could lead to climate changes due to the amount of dust and debris thrown into the atmosphere, potentially blocking sunlight and leading to a cooling effect similar to what's hypothesized after large asteroid impacts on Earth.

- **Biological Impact:** If there's life on the planet, the effects could be catastrophic, ranging from immediate destruction in the impact zone to longer-term ecological disruptions or even mass extinctions, depending on the scale of the environmental changes.

This scenario assumes an unimpeded path through space or atmosphere. In reality, interactions with the planet's magnetic field, atmosphere, or other cosmic phenomena could slightly alter these outcomes. However, the basic premise remains that such an event would be cataclysmic on a planetary scale.

[magnemoe]

2 hours ago, darthgently said:

I ran your question by grok and it agrees:

(I wish this forum formatted the eqns as nice as they look before the copy pasta operation)

  Reveal hidden contents

If a 2000-pound probe traveling at 2% of the speed of light (approximately 6,000 km/s or 3,728 miles per second) were to hit a planet, here are some potential outcomes:

- **Impact Energy:** The kinetic energy of the probe would be immense. Using the formula for kinetic energy, \(E = \frac{1}{2}mv^2\), where \(m\) is mass and \(v\) is velocity, the energy would be:

  \[
  E = \frac{1}{2} \times 907.185 \text{ kg} \times (6000000 \text{ m/s})^2 \approx 1.63 \times 10^{16} \text{ J}
  \]

  This energy release is equivalent to about 3.9 megatons of TNT, far exceeding the energy yield of most nuclear warheads.

- **Crater Formation:** The probe would create a significant impact crater. The exact size would depend on various factors like the composition of the planet's surface, but it would likely be in the range of kilometers in diameter. This impact would vaporize a large amount of material at the point of contact, sending shockwaves through the planet's crust.

- **Atmospheric Effects:** If the planet has an atmosphere, the probe would likely create a massive shockwave, potentially leading to a fireball, atmospheric heating, and possibly altering atmospheric chemistry. There could be significant atmospheric loss if the impact were strong enough.

- **Seismic Waves:** The impact would generate seismic waves, potentially causing quakes or even tsunamis if the impact site were near or under water.

- **Global Consequences:** Depending on the planet's size and composition, this could lead to climate changes due to the amount of dust and debris thrown into the atmosphere, potentially blocking sunlight and leading to a cooling effect similar to what's hypothesized after large asteroid impacts on Earth.

- **Biological Impact:** If there's life on the planet, the effects could be catastrophic, ranging from immediate destruction in the impact zone to longer-term ecological disruptions or even mass extinctions, depending on the scale of the environmental changes.

This scenario assumes an unimpeded path through space or atmosphere. In reality, interactions with the planet's magnetic field, atmosphere, or other cosmic phenomena could slightly alter these outcomes. However, the basic premise remains that such an event would be cataclysmic on a planetary scale.

So a bit like the impact in Siberia over 100 yeas ago.  I guess it would be less surface effects however.
Reasoning, I assume meteoroids  air burst because they start break up because drag and heating, who increases drag and heating who increase rate of breaking up and so on. 
An 2% of c probe wile more sturdy than an snowball will get significant heating higher up in the atmosphere. 

[Superfluous J]

Long before I understood all this (which frankly I still don't but I get the math now ) I wrote a story where the bad guys loaded a space ship full of antimatter with the attempt (thwarted at the last second by the good guys of course) to smash it into a planet at 0.1 c.

I calculated they'd need some ridiculous amount of antimatter (20 or so cubic meters of solid antimatter lead, iirc, which had its own problems). Who knew all they needed was to let the ship just hit the planet with no cargo at all.

Edited January 3 by Superfluous J

[Exoscientist]

On 12/31/2024 at 12:05 PM, Exoscientist said:

It might be Robert L Forwards idea of reflecting back the light from the main sail to a smaller sail would allow you to slow down the smaller sail to stop at the destination.

 A problem though is Dr. Forward intended this for the case of laser propulsion where the reflected light could be focused onto the receiving sail. This might not work for the non coherent light from the Sun.

 However, actually for the solar gravitational lens it still works as long as you are on a line extending out from the SGL so you may not need to slow down for that case.

 

 

In that Robert L. Forward conception of using reflected light from the main sail to slow down a smaller sail at the destination, he also included the possibility of using the same method to actually *return* from the far destination. Imagine getting returned samples from ‘Oumuamua, the Jovian and Saturnian moons, and Pluto! 

 However, there is a sticking point in using this method in the case we’re considering here. Forward was imagining it for laser propelled propulsion. In that case you can focus the reflected light that is coherent and collimated. But for our scenario we’re using solar light which will be non coherent and uncollimated. It may not be possible to get the highly focused light at long distances in this scenario. It might be we can carry a laser to do it but that may be too heavy. There may be other light weight methods to do it.

 An intriguing possibility: IF  it did work, then could it be used to do staging by sending focused light from the main sail *forward* to a smaller sail ahead of it? Then we could increase the speed multiple times by doing multiple staging.

   Bob Clark

[darthgently]

26 minutes ago, Exoscientist said:

 

In that Robert L. Forward conception of using reflected light from the main sail to slow down a smaller sail at the destination, he also included the possibility of using the same method to actually *return* from the far destination. Imagine getting returned samples from ‘Oumuamua, the Jovian and Saturnian moons, and Pluto! 

 However, there is a sticking point in using this method in the case we’re considering here. Forward was imagining it for laser propelled propulsion. In that case you can focus the reflected light that is coherent and collimated. But for our scenario we’re using solar light which will be non coherent and uncollimated. It may not be possible to get the highly focused light at long distances in this scenario. It might be we can carry a laser to do it but that may be too heavy. There may be other light weight methods to do it.

 An intriguing possibility: IF  it did work, then could it be used to do staging by sending focused light from the main sail *forward* to a smaller sail ahead of it? Then we could increase the speed multiple times by doing multiple staging.

   Bob Clark

I’m not seeing how the forces on both sails don’t cancel out in deceleration mode.  What am I missing?