Upcoming Interviews this week. Got questions?
Hey Patrons (and free members), we wanted to try out a new experiment and see if you wanted to participate in any of my upcoming interviews. These are the interviews I have scheduled for next week (Nov 11 - 15). I'll do my regular interviews and then include a few questions from the patrons. I'm going to give you my upcoming schedule of interviews this week, and just go ahead and put any questions you might have in the comments to this post:
Free members (sorry for the resend, I messed up the categorization).
Dr. Sebastian Rabien - Max Planck Institute
Membrane Space Telescope: Active Surface Control with Radiative Adaptive Optics
https://arxiv.org/pdf/2410.07741
A strategy for building a thin flexible membrane telescope mirror that could be tens of meters across, and then using lasers to change its shape in space. They've tested the concept in the lab and it seems to work.
Dr. Pekka Janhunen - Aurora Propulsion Technologies
Launching mass from the Moon helped by lunar gravity anomalies
https://arxiv.org/abs/2410.09616
The Moon is difficult to orbit because of its lumpy, bumpy gravitational field. But you could use an electromagnetic launcher to loft payloads off the Moon from very specific locations and use these gravitational anomalies for your advantage. Dr. Janhunen is the mind behind several topics I've reported on in the past, including electric sails.
Dr. Joshua Krissansen-Totton - University of Washington
The erosion of large primary atmospheres typically leaves behind substantial secondary atmospheres on temperate rocky planets
https://www.nature.com/articles/s41467-024-52642-6
It's believed that red dwarf stars will blast away the atmospheres from their planets. But there could be secondary methods of atmosphere generation that will replenish those worlds after the killer flares die down and the star settles into its trillion+ year lifespan.
Eshan Raul - University of Wisconsin–Madison
JWST Sees a Steam World
https://news.umich.edu/jwst-finds-first-exotic-steam-world-shrouded-in-water-vapor/
Astronomers have found an exoplanet with an atmosphere almost entirely comprised of water vapor - a steam world, surrounding a metallic planet. What are the implications for the search for habitable worlds?
Comments (15)
Dr. Joshua Krissansen-Totton: This idea about Secondary Atmospheres around Red Dwarfs is fascinating! It will be interesting to see if they are right about the unannounced TRAPPIST Worlds. Would this Secondary Atmosphere form before Plate Tectonics stopped on the planets? Isn’t that important for sustainability?
Aurora Propulsion Technologies, Dr. Janhunen: Could this be used to send material from one point on the Moon to another? Nine days seems like a reasonable amount of time to wait if you want to transport something from the Far Side of the Moon to the Near Side, or vice versa.
Membrane Space Telescope, Dr. Rabien: Would the laser actuators always be on, or would they only be needed when the telescope is unfurled, or if the telescope moves(assuming that would cause unintended deformation)? And could reflected light from the operation of this telescope affect other space telescopes negatively? Thank you!
Membrane Space Telescope, Dr. Rabien: Would these have to be in Deep Space (like at a Lagrange Point) to work best because of the fragile nature of the foil? I am assuming being further from Earth’s gravity and atmosphere would be best for it. Also, could the Sunlight affect the reading of the deformable surface? Meaning the telescope would have to face a certain direction to work properly.
How will a very thin flexible mirror cope with mitcometoride impacts. The bigger the mirror the bigger the area for impact. Will just the size of the mirror allow for degradation of the image small enough regards of impact damage, like a 6mm hole in the sattleite recently announced?
Furthermore, if the Foil fails can it be replaced? I'd imagine the Foil would be pretty cheap to launch. I am also assuming that the Machinery would be functional for much more time than the Membrane.
Re Steam Worlds. Are these expected to be rare since we've only just found our first one, or are we expecting many already-discovered exoplanets to be revealed to be steam worlds as they are studied in more detail? What is the expected life cycle of a steam world and does this have implications for the chances of finding objects in the Super-Earth / Mini Neptune mass gap?
@Dr. Sebastian Rabien Can a various natural lasers that emit visible light or other wavelength light, coming from universe, cause some changes of the shape to the membrane?
Dr. Joshua, if red dwarf stars take trillions of years to settle down, how much time will life need to start? Also, what exactly happens to red dwarf stars after they “die”?
For Dr. Sebastian Rabien: If not already covered in the main interview; Can the control mechanisms be fine tuned once up in space or must the controls be optimized as much as possible to the nearest possible version of their expected space environment in a lab? Also, which Lagrange point would be good or inversely not good for it’s deployment? Cheers
@Dr. Krissansen-Totton: Do you believe that this result has an impact on the estimated numerical limits of the Drake equation?
@Dr. Sebastian Rabien: If the telescope needs to do a short burn to stay in position, would the membrane be able to cope with it? And would the time to develop and build such a telescope differ compared to a „conventional“ space telescope?
@Eshan Paul: Why is probing atmospheres with heavier molecules difficult, and how does the spectral analysis method differ from what is usually done with the light of stars or nebulae?
For Dr. Rabien: To get resolution we need a mirror as large in diameter as possible, but in space this is limited by launch vehicle fairing dimensions. Is there any reason we couldn't make use of a non-circular mirror? Consider a mirror intended for optical and near-optical wavelengths that unfolds/unrolls into, say, a rectangle 3 meters wide but 100 meters long, in 10 segments of 3x10 meters each (with, of course, each segment properly curved in X and Y axes). What are the benefits and limitations of such a telescope? Call it "Mjollnir" because the final shape, including the boom for the instruments at the focus, would resemble the "Thor's Hammer" pendants worn by Viking cultures and LARP enthusiasts...
Membrane telescopes sounds really cool! Can't wait to hear the interview. If they can be adjusted using laser and they are very thin, how sensitive are they from micrometeorites, space dust and solar radiation?