Have you ever wished we could peek at all these exoplanets that have been recently discovered? We aren’t likely to visit anytime soon, but it would be possible to build a truly giant telescope that could take a look at something like that. At least according to [SciShow Space] in a recent video you can see below.
The idea put forth in a recent scientific paper is to deliberately create the conditions that naturally form gravitational lenses. If you recall, scientists have used these naturally-occurring lenses to image the oldest star ever observed. These natural super-telescopes have paid off many times, but you can’t pick what you want to look at. It is all a function of the distance to the star creating the lens and the direction a line between us points.
But what if you could create your own gravity lens? Granted, we probably aren’t going to do that in our garages. However, a recent paper talks about launching an optical detector that you could maneuver so that it was on a line that would pass through the object you want to see and our own sun. We clearly have the technology to do this. After all, we have several nice space telescopes, and several probes operating far away from the sun.
That is one of the biggest catches, though. This new telescope will need to be some 550 AU from the sun to get good results. For the record, the Earth is 1 AU (about 8 light minutes) out. Pluto — maybe not a planet anymore, but still a signpost on the way out of the solar system — is a scant 39 AU out. Voyager I, which has been racing away from the sun since 1977 is only about 156 AU out.
Because the craft would be so far out, it would be practically a one-shot mission. You also have to have something reliable enough to go the 17 years it would take with today’s technology to get in place. You also need a way to get the data back over that distance. All doable, but non-trivial.
The paper simulates what the Earth would look like using this technique from a nearby star. The images are shockingly good, especially after a bit of post-processing. Meanwhile, we may have to settle for more modest images. You might not see detail, but it is possible to find exoplanets with reasonably modest equipment.
20 thoughts on “Truly Giant Telescope Could Image Exoplanets”
I’d want to goof around closer to home first, like maybe trying to use Earth and Venus together as a synthetic aperture ‘scope. would likely need three compnents buzzing around the solar system like gas was free though.
Not sure smaller planets would work. The lower mass means they don’t bend light as much, and less lensing means the focal point is further away.
Pre-coffee I was thinking smaller diameter, closer convergence, and rocky planet dense, make shiny packets more swervy than gaseous body.
You’d also only get one target, no aiming unless you can move around the sun when 156 AU out.
Just send more. A couple hundred thousand aught to do it. Do us theoreticians have to solve all your problems?
Also the delta-v required to change orbit would be much much lower at 550 AU
Actually, not as much lower as I thought! A circular orbit would have a velocity of about 1.3 km/s vs. 29.8 at 1 AU.
“no aiming unless you can move around the sun when 156 AU out.”
You better be moving around the Sun! Otherwise you ain’t gonna stay 156 AU out very long.
This keeps rejecting my great comments.
With our luck, we would get everything set up perfect for a target planet just in time for them to experience a century of continuous cloudy weather!
But what if you accidently pointed it at the sun?
Death star, actual?
I skimmed bits of the paper.
They talk about an integration time of 1 year.
Surely the rotation and orbital motion of the planet would throw a bit of a spanner in the works there?
An integration time of 1 year means the planet/object will just look like a blurry mess anyways. We have better odds at imaging a planet using optical interferometry, but post event processing. Current technology needs the photon beam to go two different ways, where in theory you would capture the object from two different points with critically precise timing to infer the data like we are using a lens the size of the diameter between earth and the moon.
Put a huge optical telescope in orbit around every planet and moon in the solar system, also some of the larger asteroids. Put a bunch into solar orbits. That’s one huge synthetic aperture telescope.
Synchronizing their operations when there’s up to several hours light speed lag between them would be a bit of a problem to work out. The system would definitely need high speed laser data links in a mesh network. A benefit of that is it would enable getting much more data back to earth in the same time it takes to trickle data back directly from the outer reaches via radio. The laser “bucket brigade” would be more reliable, especially if the same data was sent via two or more paths.
Synthetic aperture doesn’t really work at optical wavelengths; we don’t have electronics fast enough to record phase information for optical photons. The only way to do it is via direct interferometry, which at those distances will reduce your light-gathering capability way below what you’d need to make an image.
When they show planet earth why do they never show the hole in the North Pole ?
The hole is a processing artifact. Since the earth is flat, they mathematically fold it up into a curve and the hole is where the edge was. So you can just fuzz it over.
And besides, Groth-Golka gets really annoyed at having its doorway location advertised and that’s not someone you want to upset, so that’s another good reason to fuzz it over.
There is no hole at the North Pole, unless you are referring to the one the Pole sticks out of!
Please be kind and respectful to help make the comments section excellent. (Comment Policy)