Seeing an Earth-like planet around a Sun-like star isn’t possible with current telescopes. The difference in brightness is just too big. But future space telescopes will have multiple tricks up their sleeve specifically for that. Which ones? Finding out in this interview.

🟣 Guest: Dr Bertrand Mennesson

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00:00 Intro
01:16 Resolving Earth-size world around a Sun-like star
08:13 Coronagraphs and Adaptive optics
21:10 Other ideas
34:59 Nulling
39:00 Nancy Grace Roman
43:19 Unlimited budget telescope
49:58 Current obsessions
53:33 Final thoughts

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  • @DCexpat

    Wonderful interview!!!

  • @Martin_Hermann

    NASA – Never a straight answer. Fascinating interview, Fraser!

  • @Robbadobbsoldier

    Great video Fraser. I hope you are having a great summer

  • @gary3808

    At the pace of technological advance it must be very frustrating to plan a project 10-15 yrs out.

  • @richardmarkham8369

    Another great interview. These can never be too long or too technical! Bertrand was brilliant.

  • @robertcatanzaro2982

    As a very amateur thought could their not be a retractable LCD screen on the telescope to activate pixels to block out the unwanted sun light and any background light?

  • @eruiluvatar236

    I'd like to know if things would be easier if they had a magical camera that has something crazy like 40 bits per pixel (single channel gray scale) such that it has enough dynamic range to see the one part in 10 billion without needing to occlude the billion.

    I know that such magical camera doesn't exist but I have reasons to believe that if you needed very few pixels (ideally 2 to 4) and it doesn't need to be fast, with some custom silicon it might be possible. So it wouldn't really be a camera but something built for this purpose.

    Of course I don't know if there is enough angular resolution to separate the star and planet light in two pixels or if this makes any sense for this problem.

  • @Jenab7

    How do you keep an external star shade on the line-of-sight between the telescope and the star? Differential orbital motions and light pressure will tend to drag the star shade away from that line.

  • @hughmccracken7916

    Or could our moon itself be used to suppress starlight with an orbiting observatory?

  • @hughmccracken7916

    Could there be advantages in positioning the Giant segmented screen and telescope in the moons shadow to remove solar heating effects?

  • @YousufAhmad0

    Why is skirting around how the corrections are physically actuated? Around 17:00

  • @kristinaF54

    For all the PhD's given out and intelligent people working in professional astronomy for decades and decades, it beggars belief that these astronomers are only now, in 2024, proposing to build the most important and potentially life/perception-altering telescope to identify Earth-like exoplanets orbiting around Sun-like distant stars, where such "Goldilocks planets" could host lifeforms perhaps equal (but different) to those on Earth. What took them so long to propose it? That's crazy!

  • @mikemontgomery8407

    Can't understand half of what your guest is saying.

  • @kennethpaulcalangi4122

    i think it will be a difficult task to be able to view the earth-like planet. has NASA thought of sending maybe one or couple of scientists to maybe do the exploration? i understand it would be a risk and probably a one way travel. maybe we just need a reliable but small shuttle to carry 1 or a few astronauts. and some extra fuel or booster rockets to reach a destination.

  • @caerdwyn7467

    So given that the diffraction limit is related to the wavelength in question, why not hunt in far UV?

    Shorter wavelength. For the same diameter objective, more waves, therefore a finer diffraction limit.
    Less blinding light. Stars of interest put out much less UV than visible or IR, but still enough to illuminate a planet. Less light of the appropriate wavelength to dazzle the sensor.

    What am I missing?

  • @acmelka

    Thanks for this video. I keep seeing comments and content that appears to assume we currently have the capability to detect earth-like planets around sun-like stars. Many of the 'Fermi Paradox' solutions that opine on the fantastic rarity of Earth just ignore the fact we have a sample of one on which to base our science

  • @user-sf3dw2sm3b

    We can only prove we are not alone.

  • @johnmackay3136

    Another great Interview.

    Thanks Fraser.

  • @PhonicallyPsychotic

    what about using perspective, instead of 1 large star shade send 5, 10 etc smaller shades but space them out overlapping

  • @everettputerbaugh3996

    Does the technology exist to cast a large mirror on the Moon? Would the geographic North pole of the Moon be a good place to build a large observatory using such a mirror? A slow rotation can be used to create the proper curve while the mirror blank cools…

  • @zakeller

    This was marvelous in the depth with which you talked through the details.

    My answer for what do you do if money is no object: all of the above in the biggest way possible… physically. Do an independent system with each one of these leading technologies. Specifically for the star shade concept, a few central telescopes in a Dyson-swarm-like cloud of mobile star shades, so repositioning doesn’t take nearly so long, and there’s redundancy against hardware failures and fuel limitations.

  • @ThalanorThornhale

    What about using existing structures as lenses? The sun, Jupyter or earth? By using the gravity or atmosphere to bend the light?

  • @TheJimtanker

    That and Breakthrough Starshot.

  • @myselfandi67097

    Great interview, thanks! Just to answer your question, yes we are alone. Never bet against Fermi, you'll lose every time.

  • @myselfandi67097

    Why exactly does the shield need to be star shaped? Why not just a disk, or pacman shaped or something else?

  • @Wolf-Spirit_Alpha-Sigma

    Loved this interview! He has a very good English, strong French accent, and is very smart. Perfect.

  • @MrCoxmic

    another great interview

  • @bovanshi6564

    Maybe it's selfish and entitled, but I wish you made shortened edited version/summaries of these interviews. Feels like there is a lot of interesting stuff in them but this format isn't my cup of tea at least.

  • @GRILL332

    Great great interview. Thanks

  • @Selwyndrea

    Amazing! You see what happens when people unite

  • @franciscooyarzun2637

    Would it be of use to send a coronagraph into geostationary orbit,
    that a ground telescope could look at (around), and the satellite had a
    “gentle nudge” mechanism?

  • @revmsj

    He’s right! He now has an obligation to the children to promptly show a positive bio signatures indicative of extraterrestrial life…😃👍🏾

  • @leoncorns1450

    Do planets cast a shadow in their starlight and could we identify planets using the shadow cast by a planet with a chronograph device for those face on orbital solar systems?

  • @mm-dw4rr

    Where's Prof Kipping when you need him?

  • @SpongeBob-DK

    Great interview – really informative. Thx

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