science

Startup raises $60 million claiming new particle can dim the Sun

Stardust Solutions says it has a scalable, low-cost aerosol for solar geoengineering but has not revealed the particle and is seeking regulators and governments as customers.

Apr 3rd 2026 · United States

Insights

  • Israel-US firm Stardust Solutions raised $60 million to develop a proprietary aerosol particle for solar geoengineering.
  • The company says the particle is scalable, low cost, and safe but has not disclosed its composition or independent test data.
  • Scientists warn that aerosol-based cooling can cause known harms like acid rain and ozone damage and that long-term effects of new particles are unknown.
  • Critics say a private company selling atmospheric interventions raises urgent transparency and governance questions for governments and publics.
  • Previous geoengineering tests have sparked controversy and regulation, including a 2023 ban in Mexico and halted experiments at universities.