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Nice gravitational lens observation! We're hoping to use the same technique with the Sun to observe exoplanets by launching a fleet of small satellites to 547 A

Nice gravitational lens observation! We're hoping to use the same technique with the Sun to observe exoplanets by launching a fleet of small satellites to 547 AU (80 billion km / ~3 light days). The craft would sample the distorted Einstein ring around our Sun from that vantage point, then combine and reconstruct an image of the disk of an Earth-like exoplanet up to 100 light-years beyond, at a resolution of 25 kilometers / pixel. https://orbitalindex.com/archive/2020-07-08-Issue-72/#more-on-that-solar-gravity-lens-focus-mission https://orbitalindex.com/archive/2020-07-08-Issue-72/#more-o...

sandworm101 6y ago
Not the same technique, but there are similar architectures that could be implemented far sooner. Earth's atmosphere as a refractive telescope: https://www.scientificamerican.com/article/earth-could-be-a-lens-for-a-revolutionary-space-telescope/ https://www.scientificamerican.com/article/earth-could-be-a-...
- tectonic 6y ago
  Not nearly as powerful, though.
  - sandworm101 6y ago
    That depends on the planet used. If it works for earth, the next step might be Jupiter or Saturn, something that might be possible by only repositioning the spacecraft. It may even be possible to use the sun's atmosphere, the transparent part, as a lens.
trimbo 6y ago
> it’d still take 25 to 30 years for them to reach a vantage point .... > mission designers would have to pick carefully because they could observe only a single target It will take 30 years to get in position but then we can only look at one target? While it sounds very neat, I'd rather fund something we can use more than once, and sooner.
- freeqaz 6y ago
  Still valuable as a way to observe a potentially habitable planet in more detail. If we wanted to launch a probe there, it would take a lot more time!
- mrfusion 6y ago
  We should build one for each target we want to observe. Starship is going to open so many opportunities.
- augusto-moura 6y ago
  You CAN use for more than 1 target, you just need to reposition the telescope a bit. See [1], is a great great video on the subject. I can't recommend enough [1]: https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI
- pas 6y ago
  The whole concept is that we should launch a fleet of them every few months. Very lightweight semi-autonomous smart lightsails with some optics. The first fleet helps targeting the second, and all those who come after them. https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI (already linked by a sibling comment, but yes, can't recommend this enough!)
skykooler 6y ago
25 kilometers per pixel is incredible resolution for something that far away!
- biotinker 6y ago
  That would be tremendous. Earth is 12700 km in diameter, so such an image would be a bit more than 500px across. Here is a picture of the Earth that is about 500px in diameter: https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg
  - andy_ppp 6y ago
    Do we only get a ring or do we get the whole thing? If we only get a ring why is that? Is the thing we are bending light around in the way?
    - aasasd 6y ago
      Your question seems to be sorta answered in this thread: https://news.ycombinator.com/item?id=24425595 https://news.ycombinator.com/item?id=24425595
s1dev 6y ago
How do you propose to power a fleet of spacecraft at 550AU? Would you be able to acquire enough RTGs? What about DSN time for the downlink?
- PopeDotNinja 6y ago
  And how would you get them out to, and stop at, 550 AU? Voyager 1 and 2 are nuclear powered with RTGs and they are respectively about 150 AU and 125 AU from the sun, and they are going really fast. The Voyager RTGs are also fairly depleted at this point. I’m guessing these spacecraft would need a faster, more efficient mode of propulsion, like a nuclear thruster or ion drive (or Epstein drive?!). One could also get a lot more fuel for the journey if the the probes didn’t have to launch fully fueled from the Earth’s surface.
  - rini17 6y ago
    No need to stop at 550AU, the gravitational lens keeps working beyond that(theoretically all the way to infinity). As for how to get there, yes, innovative propulsion is required. My idea is that the probe would dive close to Sun and use solar energy (sail? electric propulsion?) to accelerate itself out to hundreds of km/s.
  - 205guy 6y ago
    I was wondering how fast myself and found this: https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/ Voyager-1 is the fastest at 38,000 mph (61000 km/h) with respect to the Sun, but currently about 90,000 mph (144000 km/h) relative to earth (I guess this fluctuates annually).
  - pas 6y ago
    Sun slingshot, solar sail https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI
- pvarangot 6y ago
  That webpage says a tech demo is due 2024, with launch in 2034 and the constellation would reach 550AU by 2064, so probably a lot of how this will work is still WIP.
z92 6y ago
> 547 AU For comparison Voyager-1 is now at a distance of 40 AU only.
- dmead 6y ago
  Is that number correct? Why not just launch at those starts at that point?
  - lpghatguy 6y ago
    For comparison, the nearest star to us is 268,770 AU away, or around 491 times further away. It would take quite a bit longer to get there!
    - dmead 6y ago
      i guess i was thinking more about the complexity of arranging a constellation of telescopes around sol versus just sending one much closer to a target star.
- onlyrealcuzzo 6y ago
  Is Voyager-1 still accelerating?
  - saagarjha 6y ago
    Nope, both are slowly decelerating as they leave the solar system: https://upload.wikimedia.org/wikipedia/commons/0/0c/Voyager_speed_and_distance_from_Sun.svg https://upload.wikimedia.org/wikipedia/commons/0/0c/Voyager_...
- hashtagmarkup 6y ago
  That is not correct... it is 150 AU away from earth. https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
- cgriswald 6y ago
  That is incorrect. It's approximately at 150 AU[0]. For reference, that's about three times the distance of Pluto at aphelion. 547 AU is about 11 times the distance of Pluto at perihelion. [0] - https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
networkimprov 6y ago
It's not a new idea... I first heard of it in the intro segment of this Cool Worlds Lab vid https://www.youtube.com/watch?v=jgOTZe07eHA https://www.youtube.com/watch?v=jgOTZe07eHA
lordnacho 6y ago
How does the lensing work? Why doesn't the galaxy in the middle between us and the faraway galaxy pollute the image with its own light? It it separated by frequency or some trick?
- sp332 6y ago
  The light bends around the galaxy. You're right that looking straight at the galaxy wouldn't work, but looking just a tiny bit to the sides does.
plasticchris 6y ago
Your link suggests the satellites word need to be around 2000 AU to avoid the corona, though I suppose the delta v requirements would be pretty small for such a large change so far from the sun (but my only source for the intuition is kerbal so take it with a grain of salt).
ckosidows 6y ago
20 AU per year is a tremendous distance. Pluto is apparently right around 25 AU. Is this speed actually feasible even with solar sails? Big layman here. I only skimmed this link but this stood out to me.
mensetmanusman 6y ago
Wow.
anigbrowl 6y ago
That's really cool. If it's good enough to detect geographic features, will it be possible to photograph the same planet from the night side later in its orbit?
marsokod 6y ago
That's completely mad! I'd love to be part of that.
not2b 6y ago
That's four times as far away as Voyager 1 is. I see from the link that it would take 25 to 30 years to reach that distance, and only one target could be observed: we would have to have one particular exoplanet we want to image and go to the right point for the sun to focus the image to.
interfixus 6y ago
If that can be done, it means the light and the info is there. Meaning here. The lensing and the 550 AU are just ways to catch it. I should be highly surprised if we do not - long before 2064 - have optical and computational trickery to catch such resolution with snapshots from somewhere very close to home.

sandworm101 6y ago

Not the same technique, but there are similar architectures that could be implemented far sooner. Earth's atmosphere as a refractive telescope: https://www.scientificamerican.com/article/earth-could-be-a-lens-for-a-revolutionary-space-telescope/ https://www.scientificamerican.com/article/earth-could-be-a-...

tectonic 6y ago
Not nearly as powerful, though.
- sandworm101 6y ago
  That depends on the planet used. If it works for earth, the next step might be Jupiter or Saturn, something that might be possible by only repositioning the spacecraft. It may even be possible to use the sun's atmosphere, the transparent part, as a lens.

trimbo 6y ago

> it’d still take 25 to 30 years for them to reach a vantage point .... > mission designers would have to pick carefully because they could observe only a single target It will take 30 years to get in position but then we can only look at one target? While it sounds very neat, I'd rather fund something we can use more than once, and sooner.

freeqaz 6y ago
Still valuable as a way to observe a potentially habitable planet in more detail. If we wanted to launch a probe there, it would take a lot more time!
mrfusion 6y ago
We should build one for each target we want to observe. Starship is going to open so many opportunities.
augusto-moura 6y ago
You CAN use for more than 1 target, you just need to reposition the telescope a bit. See [1], is a great great video on the subject. I can't recommend enough [1]: https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI
pas 6y ago
The whole concept is that we should launch a fleet of them every few months. Very lightweight semi-autonomous smart lightsails with some optics. The first fleet helps targeting the second, and all those who come after them. https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI (already linked by a sibling comment, but yes, can't recommend this enough!)

skykooler 6y ago

25 kilometers per pixel is incredible resolution for something that far away!

biotinker 6y ago
That would be tremendous. Earth is 12700 km in diameter, so such an image would be a bit more than 500px across. Here is a picture of the Earth that is about 500px in diameter: https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg
- andy_ppp 6y ago
  Do we only get a ring or do we get the whole thing? If we only get a ring why is that? Is the thing we are bending light around in the way?
  - aasasd 6y ago
    Your question seems to be sorta answered in this thread: https://news.ycombinator.com/item?id=24425595 https://news.ycombinator.com/item?id=24425595

s1dev 6y ago

How do you propose to power a fleet of spacecraft at 550AU? Would you be able to acquire enough RTGs? What about DSN time for the downlink?

PopeDotNinja 6y ago
And how would you get them out to, and stop at, 550 AU? Voyager 1 and 2 are nuclear powered with RTGs and they are respectively about 150 AU and 125 AU from the sun, and they are going really fast. The Voyager RTGs are also fairly depleted at this point. I’m guessing these spacecraft would need a faster, more efficient mode of propulsion, like a nuclear thruster or ion drive (or Epstein drive?!). One could also get a lot more fuel for the journey if the the probes didn’t have to launch fully fueled from the Earth’s surface.
- rini17 6y ago
  No need to stop at 550AU, the gravitational lens keeps working beyond that(theoretically all the way to infinity). As for how to get there, yes, innovative propulsion is required. My idea is that the probe would dive close to Sun and use solar energy (sail? electric propulsion?) to accelerate itself out to hundreds of km/s.
- 205guy 6y ago
  I was wondering how fast myself and found this: https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/ Voyager-1 is the fastest at 38,000 mph (61000 km/h) with respect to the Sun, but currently about 90,000 mph (144000 km/h) relative to earth (I guess this fluctuates annually).
- pas 6y ago
  Sun slingshot, solar sail https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI
pvarangot 6y ago
That webpage says a tech demo is due 2024, with launch in 2034 and the constellation would reach 550AU by 2064, so probably a lot of how this will work is still WIP.

z92 6y ago

> 547 AU For comparison Voyager-1 is now at a distance of 40 AU only.

dmead 6y ago
Is that number correct? Why not just launch at those starts at that point?
- lpghatguy 6y ago
  For comparison, the nearest star to us is 268,770 AU away, or around 491 times further away. It would take quite a bit longer to get there!
  - dmead 6y ago
    i guess i was thinking more about the complexity of arranging a constellation of telescopes around sol versus just sending one much closer to a target star.
onlyrealcuzzo 6y ago
Is Voyager-1 still accelerating?
- saagarjha 6y ago
  Nope, both are slowly decelerating as they leave the solar system: https://upload.wikimedia.org/wikipedia/commons/0/0c/Voyager_speed_and_distance_from_Sun.svg https://upload.wikimedia.org/wikipedia/commons/0/0c/Voyager_...
hashtagmarkup 6y ago
That is not correct... it is 150 AU away from earth. https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
cgriswald 6y ago
That is incorrect. It's approximately at 150 AU[0]. For reference, that's about three times the distance of Pluto at aphelion. 547 AU is about 11 times the distance of Pluto at perihelion. [0] - https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/

networkimprov 6y ago

It's not a new idea... I first heard of it in the intro segment of this Cool Worlds Lab vid https://www.youtube.com/watch?v=jgOTZe07eHA https://www.youtube.com/watch?v=jgOTZe07eHA

lordnacho 6y ago

How does the lensing work? Why doesn't the galaxy in the middle between us and the faraway galaxy pollute the image with its own light? It it separated by frequency or some trick?

sp332 6y ago
The light bends around the galaxy. You're right that looking straight at the galaxy wouldn't work, but looking just a tiny bit to the sides does.

plasticchris 6y ago

Your link suggests the satellites word need to be around 2000 AU to avoid the corona, though I suppose the delta v requirements would be pretty small for such a large change so far from the sun (but my only source for the intuition is kerbal so take it with a grain of salt).

ckosidows 6y ago

20 AU per year is a tremendous distance. Pluto is apparently right around 25 AU. Is this speed actually feasible even with solar sails? Big layman here. I only skimmed this link but this stood out to me.

mensetmanusman 6y ago

Wow.

anigbrowl 6y ago

That's really cool. If it's good enough to detect geographic features, will it be possible to photograph the same planet from the night side later in its orbit?

marsokod 6y ago

That's completely mad! I'd love to be part of that.

not2b 6y ago

That's four times as far away as Voyager 1 is. I see from the link that it would take 25 to 30 years to reach that distance, and only one target could be observed: we would have to have one particular exoplanet we want to image and go to the right point for the sun to focus the image to.

interfixus 6y ago

If that can be done, it means the light and the info is there. Meaning here. The lensing and the 550 AU are just ways to catch it. I should be highly surprised if we do not - long before 2064 - have optical and computational trickery to catch such resolution with snapshots from somewhere very close to home.