
Direct Imaging and Spectroscopy of an Exoplanet with a Solar Gravity Lens - wooster
https://arxiv.org/abs/1802.08421
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sanxiyn
For a more critical look at this concept, I recommend "Mission to the
Gravitational Focus of the Sun: A Critical Analysis".

[https://arxiv.org/abs/1604.06351](https://arxiv.org/abs/1604.06351)

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nategri
This is insanely cool. I had no idea this was possible.

If I'm reading right the spacecraft would have to be placed at about 600-850
AU from the sun to take advantage of the solar gravity lens. For reference,
Pluto's orbit is located at (roughly) 40 AU.

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nerfhammer
could we use New Horizons to do it? ...I suppose not, it's taken 10 years for
it to go 40AU so for it to go to 400AU it would take 100 years...

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rbanffy
You'd probably need to pack a multi-mode propulsion system. Launch it so it
can get a gravity assist from the Sun, deploy a solar sail after closest
approach (or when safe) and ride the light pressure from the Sun to get as
much delta-v as you can, then ditch the sail and fire up nuclear-powered
electric thrusters for the rest of the trip. Dropping the solar sail part may
be a good idea if its weight could be better used as propellant for the ion
drive.

Then you have a hope of making the trip in a couple decades

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londons_explore
Presumably when you get to the right distance, you'd want to circularise your
orbit so you can use your new solar lens to look in many different directions.

Even more dV and time required to do that...

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rbanffy
Yes... There will be a lot of braking involved, but we may start doing
observations well before it reaches the intended circular orbit. I wonder how
much such a mission would cost.

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coldnose
This sounds like moonshot-level complexity. It invokes solar sails, laser
communication at 550 AU, as well as "advanced propulsion, lightweight
telescopes, membrane mirrors, inflatable/rigidizeable structures, and novel
coronagraphic techniques." All that for a telescope you can't aim...

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IntronExon
Moonshot x Manhattan Project with a dash of Star Trek. Basically we need the
next few generations of novel materials, and controlled fusion reactions.
Assuming no major setbacks for humans, we’d need more than a century before
considering this kind of project. It would be a worthy project, although I
wonder if some other tech might not supersede it by the time this was ready?
Gravitational astronomy is just getting started after all, and who knows,
maybe the dream of neutrino astronomy could happen.

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skew
Interesting that you mention neutrino astronomy - if you mean imaging, I don't
know of anything but gravity that could focus neutrinos.

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curtis
I've wondered for a while if this could be done. I guess now I know. The
potential for exploiting the Sun as a gravitation lens comes up on Centauri
Dreams from from time to time (see
[https://www.google.com/search?q=%22gravitational+lens%22+sit...](https://www.google.com/search?q=%22gravitational+lens%22+site%3Acentauri-
dreams.org)).

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mturmon
This is the workshop where some of these ideas were discussed:
[http://kiss.caltech.edu/workshops/ism/ism.html](http://kiss.caltech.edu/workshops/ism/ism.html)
There appear to be several groups working on related designs for gravity-based
imagers.

One of the three organizers of the workshop is Ed Stone, who is the Voyager
PI.

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cromwellian
NASA's WFIRST mission is trying to do gravitional microlensing observations,
but Trump's latest budget kills it.

[https://en.wikipedia.org/wiki/Wide_Field_Infrared_Survey_Tel...](https://en.wikipedia.org/wiki/Wide_Field_Infrared_Survey_Telescope)

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sanxiyn
Note that gravitational microlensing is a completely different technique from
solar gravitational lensing discussed in the linked paper.

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loxias
Is there anyone who's sufficiently qualified in astronomy/astrophysics who
could point out what advances in HPC/modelling/signal processing will be
necessary to accelerate things like this?

I don't know telescopes but I know enough about DSP to make me suspect this is
gonna need all sorts of fun high performance deconvolution algorithms....

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pizza
Related projects [0]

Imaging With Nature: Planet Sized Sensors (July 24th, 2010)

Imaging With Nature: A Cloud Based Sun Imager (July 25th, 2010)

A Galaxy Wide Single Pixel Camera (November 6th, 2010)

[0]
[https://sites.google.com/site/igorcarron/thesetechdonotexist](https://sites.google.com/site/igorcarron/thesetechdonotexist)

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Scaevolus
Using the sun as a gravitational lens is our current best option for
interstellar communications, presuming we settled a planet within a hundred
light years:

[https://www.centauri-dreams.org/2009/11/06/the-
gravitational...](https://www.centauri-dreams.org/2009/11/06/the-
gravitational-lens-and-communications/)

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jagger27
While forming a complete image is no doubt very cool, just a few fragments of
light spectrum would give us incredible insight on its own.

I'm wondering now if with BFR we could pre-place fuel in the slingshot path to
get it there quicker and depend less on the Sun gravity slingshot.

