Over the past decade or so, astronomers have speculated about the characteristics of rogue planets in the Milky Way Galaxy. These "free-floating" worlds don't orbit stars, but instead roam the spaceways. They're hard to spot with current technology, but the upcoming Nancy Grace Roman Space Telescope (Roman) will be a perfect instrument to find them and give insights into the history and features they may have in common with Solar System worlds.
One of the unanswered questions in astronomy is just how supermassive black holes grew so big, so quickly. A team of astronomers have tried to answer this question by searching for actively feeding supermassive black holes (aka quasars) as a way to measure how much material material they are actually accumulating. They studied nebulae near the quasars that light up with the quasar is releasing radiation and found that many of the more distant quasars have only been active for a few hundred thousand years, not long enough to grow to the size we see today.
Spring is a miserable season for those with seasonal allergies. There are effective drug- and non-drug measures that can control most symptoms effectively.
The post Breathing Easy: Treating Allergic Rhinitis first appeared on Science-Based Medicine.This is an intriguing idea, and one that I can see becoming critical over the next few decades, or never manifesting – developing a fleet of floating nuclear power plants. One company, Core Power, is working on this technology and plans to have commercially deployable plants by 2035. Company press releases touting their own technology and innovation is hardly an objective and reliable source, but that doesn’t mean the idea does not have merit. So let’s explore the pros and cons.
The first nuclear-powered ship, the USS Nautilus, was deployed in 1955. So in that sense we have had ship-based nuclear reactors operating continuously (collectively, not individually) for the last 70 years. Right now there are about 160 nuclear powered ships in operation, mostly submarines and aircraft carriers. They generally produce several hundred megawatts of electricity, compared to around 1600 for a typical large nuclear reactor. They are, however, in the range of small modular reactors which have been proposed as the next generation of land-based nuclear power. The US has operated nuclear powered ships without incident – a remarkable safety record. There have been a couple of incidents with Soviet ships, but arguably that was a Soviet problem, not an issue with the technology. In any case, that is a very long record of safe and effective operation.
Core Power wants to take this concept and adapt is for commercial energy production. They are designing nuclear power barges – large ships that are designed only to produce nuclear power, so all of their space can be dedicated to this purpose, and they can produce as much electricity as a standard nuclear power plant. They plan on using a Gen IV salt-cooled reactor design, which is inherently safer than older designs and does not require high pressure for operation and cooling.
The potential advantages of this approach are that these nuclear barges can be produced in a centralized manufacturing location, essentially a shipyard, with allows for economies of scale and mass production. They intend to leverage the existing experience and workforce for shipyards to keep costs down and production high. The barges can then be towed to the desired location. Core Power points out that 65% of economic activity occurs in coastal regions, therefore the demand for power there is high, and offshore power could provide some of that demand. Nuclear barges could be towed into port or they could be anchored farther off shore. Maintenance and waste disposal could all be handled centrally. Since there is no site preparation, that is a huge time and cost savings. Further there is no land use, and these barged could be place relatively close to dense urban centers.
There are potential downsides. The first that comes to mind is that there isn’t a pre-existing connection to the grid. One of the advantages of land-based nuclear is that you can decommission a coal plant and then build a nuclear power plant on the same site and use the same grid connections. This of course is not a deal killer, but it will require new infrastructure. A second issue is safety. While ship-based nuclear has a long and safe history, this would be a new design. Further, a radiation leak in a coastal environment could be disastrous and this would need to be studied. I do think this concept is only viable because of the salt-cooled design, but still it will require extensive safety regulation.
And this relates to another potential problem – the mid-2030s is likely ambitious. While I think we should “warp speed” new nuclear to fight climate change, this unfortunately is not likely to happen. New projects like this can get bogged down in regulation. Safety regulation is, in itself, reasonable, and it will likely be a tough sell to speed up or streamline safety. There is a reasonable compromise between speed and safety, and I can only hope we will get close to this optimal compromise, but history tells a different story.
What about the usual complaint of nuclear waste? This is often the reason given for those who are anti-nuclear. I have discussed this before – waste is actually not that big a problem. The highly radioactive waste is short-lived, and the long half-life nuclear waste is very low level (by definition). We just need to put it somewhere. Right now this is purely a political (mostly NIMBY) problem, not a technology problem.
On balance it seems like this is an idea worth exploring. Given the looming reality of climate change, exploring all options is the best way forward. Also, Core Power plans, as a phase 2, to adapt their technology for a commercial fleet of nuclear powered ships. Ocean shipping produces about 3% of global CO2 emissions, which is not insignificant. If our cargo carriers were mostly nuclear powered that could avoid a lot of CO2 release. They are also not the only company working on this technology. A nuclear cargo ship would have more space for cargo, since it doesn’t need to carry a lot of fuel for itself. It would also be able to operate for years without refueling. This means it can be commercially viable for shipping companies.
Maritime nuclear power may turn out to be an important part of the solution to our green house gas problem. The technology seems viable. The determining factor may simply be how much of a priority do we make it. Given the realities of climate change, I don’t see why we shouldn’t make it a high priority.
The post Floating Nuclear Power Plants first appeared on NeuroLogica Blog.
The Fermi Paradox presents us with a striking contradiction: despite the high probability of numerous civilizations existing throughout the Universe, we've encountered no evidence or communication from any alien intelligence. A new paper just published calculates that we should have a 99% chance of detecting at least one signal from another civilisation—assuming they survive for several hundred years and could be distributed anywhere across the Milky Way galaxy. This calculation further deepens the mystery of our apparent cosmic solitude.
On May 7th, the Japanese space exploration company ispace announced that its HAKUTO-R RESILIENCE lander entered lunar orbit after completing a 9-minute thruster burn. It's now in a stable lunar orbit, and operators will spend the next month testing and preparing for its landing attempt on June 5. This is the company's second attempt at landing on the Moon, after the first attempt crashed in 2023. It's carrying a micro-rover and several science experiments.
NASA’s Psyche mission is on its way to explore a metal-rich asteroid in the asteroid belt between Mars and Jupiter. All was going well since its launch in October 2023 until nasa announced a decrease in fuel pressure for the propulsion system. It uses a solar electric propulsion system, generating thrust with four electric ion engines that expel xenon ions, giving the spacecraft a gentle nudge in the opposite direction. It has been firing its thrusters continuously since May 2024, but in April 2025, engineers detected the pressure drop. Thankfully they have redundancy built in but are still troubleshooting the issue.
The most massive stars in the Milky Way contain one hundred times more mass than the Sun, even more in some cases. These O-type stars are extremely hot, luminous, and blue, and often die in supernova explosions. Astrophysicists want to know how they get so big, and a simple household chemical might hold the answer.
When ISS astronauts return home, they have a hot ride back to Earth's surface. It's been that way since the beginning of human spaceflight to orbital space and beyond. The incoming vehicle uses friction with Earth's atmosphere to slow down to a safe landing speed. The "hot ride" part comes because that friction builds up high temperatures on the spacecraft's "skin". Without protection, the searing heat of atmospheric re-entry could destroy it. This same heating happens to incoming meteoroids as they whip through Earth's atmosphere.
If astronomy has a Holy Grail, it's another habitable world. To find one, NASA is working with partners to develop the Habitable Worlds Observatory (HWO). The HWO would be the first telescope built to detect Earth-like planets around Sun-like stars. China is building the Closeby Habitable Exoplanet Survey (CHES), and new research shows that by working together, HWO and CHES would amplify their results.