NASA study reveals Venus crust surprise

Original Article ↗ Hacker News Discussion ↗

Terraforming concepts and atmosphere removal

  • Multiple speculative schemes discussed:
    • Sunshade at Venus to end the runaway greenhouse, possibly freezing out the atmosphere and then ejecting CO₂ with mass drivers.
    • Using asteroids to “nick” the atmosphere and knock gas into space, or angled impacts to add rotational momentum.
    • Mega-scale “vacuuming” concepts (space elevators or “MegaMaid”-style devices) to blow atmosphere into space or the Sun, with concerns about enormous energy cost and perturbing Venus’s orbit.
    • Shipping excess Venusian CO₂ to Mars, though noted this would wildly over-pressurize Mars if done in full.
  • Some prefer in‑situ management of carbon to keep it available for organics, rather than ejecting it from the system.
  • Mars’s lack of a magnetosphere is raised: added atmosphere would be stripped over ~100k–million-year timescales. Ideas include an artificial magnetic shield at a Mars Lagrange point.

Water, hydrogen loss, and climate feedbacks

  • One line of discussion: Venus’s catastrophe started with water-vapor greenhouse (H₂O ~10× more potent than CO₂), which then liberated CO₂ from rocks.
  • Others emphasize that Venus is now extremely dry: lighter gases and water vapor were blown away by the solar wind; most hydrogen has escaped.
  • Debate whether adding water now would help or just “pour petrol on the fire.” One view: water is mainly an amplifier; if CO₂ is removed, equilibrium water levels could be safe.

Rotation and extreme geoengineering

  • Venus’s retrograde day is longer than its year, seen as a major habitability problem even beyond the atmosphere.
  • Proposals include using nukes or cleverly angled asteroid impacts to change rotation; one commenter jokingly suggests vaporizing Venus and rebuilding it.

Floating habitats vs full terraforming

  • Strong advocacy for high-altitude habitats at ~50 km:
    • Pressure ~1 bar and temperatures compatible with human life.
    • Venus’s CO₂–N₂ atmosphere makes Earth air a lifting gas, enabling floating cities.
    • High gravity (~0.9 g) and atmospheric shielding make it arguably the best post‑Earth environment if used as‑is.
  • Counterpoints:
    • Psychological discomfort with living on balloons and extreme consequences of failure.
    • Acknowledgment that everything about Venus settlement is science fiction for now, and likely harder than Moon or orbital habitats.

Comet‑based “humidification” plan

  • A stepwise proposal:
    1. Redirect tens of thousands of Oort-cloud comets to add water and create a reflective cloud envelope, cooling the planet.
    2. Form oceans once temperatures drop.
    3. Split CO₂; oxygen oxidizes surface iron, carbon is sequestered under oceans (a “carboniferous” era).
    4. End state: mostly N₂ atmosphere (~3 bar), possibly breathable later.
  • Claimed timescale: 2,000–5,000 years, using thermonuclear devices to nudge comets. Others question whether this really avoids “exotic-level” engineering.

NASA Venus missions and budget politics

  • The DAVINCI mission is noted as cited in the article but asserted to be canceled in the latest U.S. budget proposal, amid claims that ~50% of NASA science funding is slated for cuts.
  • Some urge contacting Congress to oppose cuts; others are cynical that calls matter given party-line voting and prior experiences.
  • Clarifications:
    • The presidential budget is only a proposal; Congress ultimately sets the budget, so nothing is definitively canceled yet.
    • References to wider context: possible future cancellation of SLS, concurrent growth of commercial launch; concern that U.S. science leadership may shift to China.

Geology, craters, and resurfacing

  • Commenters are struck by the abundance of volcanoes and relative paucity of craters, implying frequent resurfacing.
  • One suggests the thick atmosphere itself filters out many impactors, so crater counts might understate bombardment.

Two-habitable-planets speculation

  • Regret expressed that slightly different evolution could have left both Earth and Venus as water worlds; Mars is seen as too small for long-term habitability.
  • Thought experiment: two intelligent civilizations on neighboring planets.
    • Skepticism that two human-level intelligences would overlap in time, given long evolutionary timescales versus rapid tech development.
    • Others argue we set anthropocentric “intelligence” criteria and might miss different forms.
  • Debate over when cross-planet communication could begin:
    • Some think early telescopic observers could quickly attempt visual signaling via large-scale patterns of light/dark or fires.
    • Others argue practical resolution limits and engineering scale make this nontrivial.

Miscellaneous and humor

  • Numerous food puns on “Venus Crust Surprise,” plus jokes about “gastronomy vs astronomy.”
  • Side discussion of planetary mass factoids (Earth vs inner solar system; Venus ~80% Earth’s mass; Sun’s dominance).
  • Reference to a 1995 NOVA episode on Venus; the new crust thickness estimate (~25–40 miles) prompts questions about whether this is “thick” or “thin,” with no clear consensus in the thread.