An Israeli tech company founded by former nuclear physicists is preparing to release millions of tons of microscopic particles into the Earth’s upper atmosphere to reflect sunlight back into space, and they say they’ll be ready to test it outdoors very soon. The company, Stardust Solutions, has raised $75 million from Silicon Valley investors and European holding companies, applied for a patent, and is already in conversations with governments about who gets to set the rules. The particles, long kept secret under nondisclosure agreements, turn out to be amorphous silica, a common food additive, and calcium carbonate, the stuff of eggshells and limestone. Benign ingredients, or so they claim, but some worry it will have planetary consequences.
The project’s ambitions are staggering: disperse 10 million tons of particles across the stratosphere over several years, cool the Earth by 1.5 degrees Celsius, and do it for roughly $10 billion. “This is a very powerful tool that will be ready for testing very soon, and we want policymakers to start thinking seriously, ‘What will it take in practice?'” CEO Yanai Yedvab told the New York Times.
The prophet Joel did not frame a darkened sun as a technological achievement, but, rather, as an end-of-days warning from God: “And I will shew wonders in the heavens and in the earth, blood, and fire, and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the great and terrible day of the LORD come” (Joel 2:30–31). The darkening of the sun in Scripture is a sign of Divine judgment, not a startup deliverable.
Stardust Solutions, registered as a US company with an Israeli subsidiary and a laboratory in Ness Ziona, south of Tel Aviv, was founded in 2023 by two nuclear physicists who previously worked for the Israeli government. The company’s plan is to mimic the natural cooling effect of massive volcanic eruptions. When Mount Pinatubo erupted in the Philippines in 1991, the second-largest eruption of the 20th century, global temperatures dropped by roughly 0.9 degrees Fahrenheit for two to three years. Stardust wants to replicate that effect indefinitely, on demand, without the volcano.
The company claims its particles are biodegradable, harmless to people and animals, and will not accumulate in soil or oceans. Unlike the sulfur particles that volcanoes eject, which damage the ozone layer and cause acid rain, Stardust says its silica-and-carbonate formula is inert. The plan is to disperse the particles at roughly 11 miles above sea level in the stratosphere. Controlled outdoor experiments, releasing particles from a modified aircraft, were planned to begin as early as April.
The scientific community is not reassured. More than 600 scientists and academics have signed a petition calling for an international ban on solar geoengineering projects. Tennessee and Florida have already enacted state-level bans. Mexico banned solar geoengineering experiments entirely after an unauthorized 2023 test in Baja California. A test backed by Bill Gates over Sweden was canceled in 2021 after public opposition.
Prakash Kashwan, a professor of environmental studies at Brandeis University, has warned that solar geoengineering could disrupt the annual monsoon patterns on which billions of people depend for their food supply. “There’s this social risk for at least two billion people that is directly connected to the lack of scientific understanding about how interfering with the global temperature thermostat is going to interfere with the monsoon formation,” Kashwan told the Times. “We don’t have a solution for those kinds of risks.”
Gernot Wagner, a climate economist at Columbia Business School and author of Geoengineering: The Gamble, told Politico bluntly that Stardust’s business model does not hold up. “They have convinced Silicon Valley venture capitalists to give them a lot of money, and I would say that they shouldn’t have,” Wagner said. “I don’t think it is a reasonable path to suggest that there’s going to be somebody, the U.S. government, another government, whoever buys Stardust, buys the intellectual property for a billion bucks and makes the VC investors gazillions.”
Scientists are also concerned about what they call “termination shock.” If a solar geoengineering program were suddenly discontinued due to funding collapse, political instability, or war, global temperatures would spike rapidly, creating a thermal crisis for generations who never agreed to the experiment in the first place. The entire architecture of the program rests on the assumption that it will be maintained indefinitely by governments that cooperate across borders and across political cycles. History offers no precedent for that kind of sustained international coordination.
The Sages teach that the generation that built the Tower of Babel possessed remarkable knowledge and engineering capabilities. Their sin was not stupidity; it was the conviction that their power placed them beyond accountability to the Creator. They sought to plant themselves in the heavens. The result was the dissolution of their unity and the scattering of their civilization.
Stardust Solutions’ investors include Silicon Valley’s Lowercarbon Capital, Exor—the Agnelli family holding company that controls Ferrari, Stellantis, and Juventus —and former Facebook executive Matt Cohler, among ten other venture capital firms stretching from San Francisco to Berlin. These are not reckless actors by the standards of their world. They are sophisticated, well-resourced, and convinced they are solving a problem. That is precisely what makes the project alarming. The Tower of Babel was not built by fools.
The Biden administration funded geoengineering research, despite public denials. The UK’s Advanced Research and Invention Agency has set aside $66.5 million for similar work. Some scientists have even proposed redirecting moon dust toward Earth as a solar shield. The direction of travel is clear: the technology is advancing, the money is flowing, and the regulatory frameworks are not keeping pace.
Joel’s warning stands. A darkened sun is not a climate solution. In Scripture, it is the signature of the Day of the Lord. Those who accelerate its conditions through human technology are not averting judgment. They are rehearsing it.