Adam Frank - How We Will Use The Sun As A Telescope To Image Alien Cities?

• Key Takeaways
  
  • Exoplanets are the hottest topic in astronomy right now. But if we really want to know what is happening on planets many light-years away, we need to image them.
  • According to Einstein’s general theory of relativity, massive objects bend spacetime in such a way that they can act like giant lenses.
  • By the 2060s, we might begin to record images of alien planets, revealing alien river systems, alien mountain ranges, strings of alien islands, alien deserts, alien peninsulas — and perhaps alien cities.

Episode Transcript

(00:01):
How to use the Sun as atelescope to wimage alien cities. Big think.
Exoplanets are the hottest topic in astronomyright now. After the discovery of
the first planet orbiting a sunlike starin nineteen ninety five, the field exploded,
revealing that nearly every star in thesky hosts a family of worlds.

(00:25):
Powerful advances in technology are just nowstarting to give us the capacities to detect
biological or even technological markers in theatmospheres of these alien worlds. That is
all very exciting, but if wereally want to know what is happening on
planets many light years away, weneed to image them. High resolution images

(00:46):
of green pocked continents could reveal thepresence of life. High resolution images of
those same continents at night, dottedwith the lights of cities could reveal the
presence of civilizations. Unfortunately, welack the ability to create such images.
They have been nothing more than apipe dream for astronomers, but that is

(01:07):
changing now. Allow me to introduceyou to the solar gravitational lens telescope using
the Sun to focus on exoplanets.Resolution depends on the size of your telescope.
It takes a very large telescope.Indeed, to directly resolve surface features
on even the closest exoplanets. Toachieve a resolution of one meter on an

(01:30):
exoplanet would require a telescope the sizeof Earth's orbit. Good luck getting funding
for that, even if it werepossible to build one. Luckily, there
is another way to gather light ona large scale. According to Einstein's general
theory of relativity, a massive objectbends spacetime in such a way that it

(01:51):
can act like a giant lens,collecting and focusing the passing light waves.
The use of such gravitational lenses isnow standard practice in cosmology. Four ground
galaxy clusters produce images of background objects, such as more distant galaxies. Since
telescopes work by collecting and focusing passinglight waves, couldn't we use the sun,

(02:15):
our local great collection of mass asa very very big telescope. This
is one of those ideas that seemskind of crazy, even though it may
be plausible in theory. But thanksto a team of researchers, including Slavatori
Chev, a scientist at NASA's JetPropulsion Laboratory JPL, we know the idea

(02:36):
may actually be practical, and wecould use it to procure images of exoplanets
with resolutions of just tens of kilometers. That's close enough to see cities on
the surface of an alien world.A forty year plan to image alien cities.
Hey race How it works. Asthe light from a distant object passes

(02:57):
the Sun, its mass distort spacetime such that the light rays focus onto
a line that begins about five hundredand fifty astronomical units away. An astronomical
unit, or a U is thedistance from the Sun to the Earth.
At that distance, light from anexoplanet would form a ring around the Sun.
If you could get a telescope outthat far, it could collect the

(03:21):
light in the ring and use itto reconstruct an image of the exoplanet.
There are still problems that need tobe dealt with, such as the influence
of light from the Sun and itscorona, but Tuurischev and his collaborators have
already shown these challenges can be dealtwith In an amazing sequence of work.
They have demonstrated from an imaging technologyperspective that a telescope at five hundred and

(03:45):
fifty Australian dollars could indeed produce ultrahigh resolution images of alien planets. So
sure, all you have to dois get a telescope five hundred and fifty
Australian dollars from the Sun. Thefarthest we have ever gotten from the Sun
is the Voyager one probe, whichafter flying for more than forty years,

(04:06):
is only about one hundred to sixtyAustralian dollars away. Two. Rischev's team
has a radical plan for getting tofive hundred and fifty Australian dollars in just
about twenty years. The idea isto use a new kind of highly maneuverable
solar sale that will use solar photonsto reach incredible speeds. The mission design

(04:28):
calls for clusters of sail powered spacecraftto be launched every year or so,
forming a flotilla making its way outof the Solar System. By first diving
close to the Sun where the lightis most intense, each spacecraft cluster can
establish a fast trajectory out to thesolar focus line. Once the clusters of
spacecraft reach their destination, they willuse artificial intelligence to self assemble into a

(04:55):
telescope. Then they will begin collectingclose up images of distant worlds. The
idea is so audacious that it seemslike science fiction, but it is not.
The j p L team has beensteadily working their way through the nas
emission concept process. They have demonstratedthe feasibility of all the key components of

(05:15):
their solar gravitational lens telescope, andare continuing to work It. All seems
to be both possible and feasible,at least so far. If things continue
to work out, we might seethe first launches in a decade. By
the twenty sixties, we might beginto record images of alien planets, revealing
alien river systems, alien mountain ranges, strings of alien islands, alien deserts,

(05:43):
and alien peninsulas. Somewhere in allthat detail, we might even get
the evidence we need to know thatalien life is down there too,