Talks to Watch

The REAL Possibility of Mapping Alien Planets!

778K views · Oct 12, 2022 · 21:15 · 4 HN recommenders · 7 mentions · discussed 2023–2024

PBS Space Time explains the proposal to use the Sun's gravity as a giant lens, sending a train of small light-sail spacecraft to the focal point roughly 550 AU out. It covers how such a telescope could image exoplanets in surprising detail and the engineering challenges involved.

Why Hacker News points people here: It is the go-to explanation whenever a thread touches on imaging exoplanets or solar gravitational lens telescopes.

“Pretty good explanation of the technique and challenges involved”HN comment, 2023

What Hacker News said 7

Strongly recommendslasc4rJun 2023

“If you think LISA is mad this will blow your mind.”

Mind-blowing Space Time episode

Full comment

I feel like you need to see _this_ spacetime video: this video If you think LISA is mad this will blow your mind.

in “Monster gravitational waves spotted for first time” · view on HN
RecommendsnkriscJan 2023

“Pretty good explanation of the technique and challenges involved”

Explains imaging exoplanets with solar gravitational lens and its challenges

Full comment

Pretty good explanation of the technique and challenges involved: this video One figure that stands out, the probe would need to be about 550 AU from the sun. Voyager 1 is about 150 AU away from the sun right now, for comparison.

in “Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star” · view on HN
RecommendsGalaxeblafferMar 2023

“good old Space Time has a pretty good video on this”

Space Time video on gravitational lens telescopes

Full comment

good old Space Time has a pretty good video on this this video and it might even be possible and more feasible to use planets link and even earth link as lenses

in “JWST gets best view yet of planet in hotly pursued star system” · view on HN
RecommendstzsJan 2024

“Here's a PBS Space Time episode [1] that talks about this general topic”

Covers gravitational lens telescope and swarm of small light-sail telescopes

Full comment

That's one approach to use the sun as a gravitational lens for looking at exoplanets. There's another approach that instead of one big telescope sends a series of much smaller telescopes, small enough that light sails would be effective for getting them to where they need to go. Here's a PBS Space Time episode [1] that talks about this general topic, and then about the series of smaller telescopes approach. [1] this video

in “Rumors Circulating That James Webb Has Discovered Life on Another World” · view on HN
RecommendstzsFeb 2024

“Here's a PBS Space Time episode that talks about the proposals for building a Sun based gravity lens telescope [1].”

Proposals for a Sun-based gravity lens telescope

Full comment

Yes, it is possible. Briefly, you use your solar system's star as a gravitational lens. There are currently a couple proposals working their way through the system to do that here in our solar system. It doesn't require technology much beyond what we already have, nor is it much more expensive than other unmanned deep space missions. We wouldn't be able to see pyramid sized objects on alien planets that way because the Sun is only about 1.4 million km diameter, and from other comments it would take a few million km. But for aliens with a bigger star? No problem. Here's a PBS Space Time episode that talks about the proposals for building a Sun based gravity lens telescope [1]. [1] this video

in “Are we visible to advanced alien civilizations?” · view on HN
RecommendstzsOct 2024

“It starts getting into the specifics of those approaches at 7 minutes in”

Different proposals for solar gravitational lens, specifics from 7 minutes

Full comment

Here's a PBS Space Time episode [1] from a couple years ago that describes a couple different proposals for how to do this that take quite different approaches. It starts getting into the specifics of those approaches at 7 minutes in if you don't need the introductory material. [1] this video

in “A solar gravitational lens will be humanity's most powerful telescope (2022)” · view on HN
Cites ithackerlightJan 2024

“presumably advanced alien technology can go further. See for example[2].”

Advanced technology could detect planets from farther away

Full comment

Right, human technology can detect up to hundreds of light years[1], but presumably advanced alien technology can go further. See for example[2]. Hard to say how far. [1] link [2] this video

in “Are we stuck with the Zoo Hypothesis?” · view on HN