17th century scientist Christiaan Huygens set his sights on faraway Saturn, but he may have been nearsighted.

Huygens is known, in part, for discovering Saturn’s largest moon, Titan, and deducing the shape of the planet’s rings. But by some accounts, the Dutch scientist’s telescopes produced fuzzier views than others of the time despite having well-crafted lenses.

That may be because Huygens needed glasses, astronomer Alexander Pietrow proposes March 1 in Notes and Records: the Royal Society Journal of the History of Science.

To make his telescopes, Huygens combined two lenses, an objective and an eyepiece, positioned at either end of the telescope. Huygens experimented with different lenses to find combinations that, to his eye, created a sharp image, eventually creating a table to keep track of which combinations to use to obtain a given magnification. But when compared with modern-day knowledge of optics, Huygens’ calculations were a bit off, says Pietrow, of the Leibniz Institute for Astrophysics Potsdam in Germany.

One possible explanation: Huygens selected lenses based on his flawed vision. Historical records indicate that Huygens’ father was nearsighted, so it wouldn’t be surprising if Christiaan Huygens also suffered from the often-hereditary affliction.

Assuming that’s the reason for the mismatch, Pietrow calculates that Huygens had 20/70 vision: What someone with normal vision could read from 70 feet away, Huygens could read only from 20 feet. If so, that could be why Huygens’ telescopes never quite reached their potential.

Aled Roberts and Nigel Scrutton used simulated Martian soil mixed with potato starch and a pinch of salt to create the material that is twice as strong as ordinary concrete and is perfectly suited for construction work in extraterrestrial environments. Image credit: Aled Roberts & Nigel Scrutton, doi: 10.1515/eng-2022-0390.

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A sustained human presence on the lunar and Martian surfaces will require habitats with thick walls and ceilings for protection against radiation exposure and meteor strikes.

Due to the high cost of transporting mass from Earth to space, bulk construction materials will be produced from locally available resources — a concept known as in situ resource utilization.

The stabilization of loose, unconsolidated regolith (i.e., dust and soil) into a solid concrete-like material would not only provide radiation- and micrometeoroid-shielding, but could also allow the deployment of relatively lightweight, inflatable habitats by countering the extreme thermal and pressure differences between indoor and outdoor environments.

Although there have been several proposed solutions to the stabilization of regolith for extraterrestrial construction, most have major drawbacks such as extremely high energy or water use, or the need for additional high-mass mining, transportation, processing or fabrication equipment which would add to the cost and complexity of any mission.

One potential solution is the use of naturally occurring biopolymers as regolith binding agents to produce extraterrestrial regolith biocomposites.

Starch is an abundant plant-based carbohydrate and is the main source of calories in the human diet.

In addition to food, starch is also employed industrially as an adhesive/binder for various applications — including paper, cardboard, and textile manufacture.

Starch has been extensively investigated as a binder for plant fiber-based biocomposite materials; however, relatively poor mechanical properties and moisture sensitivity limit their applicability.

In the new research, University of Manchester scientists Aled Roberts and Nigel Scrutton demonstrated that starch can act as a binder when mixed with simulated Mars dust to produce a concrete-like material.

When tested, StarCrete had a compressive strength of 72 Megapascals (MPa), which is over twice as strong as the 32 MPa seen in ordinary concrete.

StarCrete made from the lunar dust was even stronger at over 91 MPa.

“Current building technologies still need many years of development and require considerable energy and additional heavy processing equipment which all adds cost and complexity to a mission,” Dr. Roberts said.

“StarCrete doesn’t need any of this and so it simplifies the mission and makes it cheaper and more feasible.”

“And anyway, astronauts probably don’t want to be living in houses made from scabs and urine!”

The researchers calculated that a sack (25 Kg) of dehydrated potatoes (crisps) contain enough starch to produce almost half a ton of StarCrete, which is equivalent to over 213 brick’s worth of material. For comparison, a 3-bedroom house takes roughly 7,500 bricks to build.

Additionally, they discovered that a common salt, magnesium chloride, obtainable from the Martian surface or from the tears of astronauts, significantly improved the strength of StarCrete.

The next stages of this project are to translate StarCrete from the lab to application.

“It is worth noting that since cement and concrete account for about 8% of global carbon dioxide emissions, further development of StarCrete could result in a relatively sustainable alternative for Earth-based construction,” the scientists said.

“For this to be achieved, the moisture-sensitivity of starch binder needs to be overcome.”

“This could be achieved through the incorporation of covalent crosslinking agents, heat-induced crosslinking, or other biopolymer additives such as proteins, waxes, or terpene-based resins.”

Their work was published in the journal Open Engineering.

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Aled D. Roberts & Nigel S. Scrutton. 2023. StarCrete: A starch-based biocomposite for off-world construction. Open Engineering 13 (1); doi: 10.1515/eng-2022-0390

THE WOODLANDS, TEXAS — Martian dirt may have all the necessary nutrients for growing rice, one of humankind’s most important foods, planetary scientist Abhilash Ramachandran reported March 13 at the Lunar and Planetary Science Conference. However, the plant may need a bit of help to survive amid perchlorate, a chemical that can be toxic to plants and has been detected on Mars’ surface (SN: 11/18/20).

“We want to send humans to Mars … but we cannot take everything there. It’s going to be expensive,” says Ramachandran, of the University of Arkansas in Fayetteville. Growing rice there would be ideal, because it’s easy to prepare, he says. “You just peel off the husk and start boiling.”

Ramachandran and his colleagues grew rice plants in a Martian soil simulant made of Mojave Desert basalt. They also grew rice in pure potting mix as well as several mixtures of the potting mix and soil simulant. All pots were watered once or twice a day.

Rice plants did grow in the synthetic Mars dirt, the team found. However, the plants developed slighter shoots and wispier roots than the plants that sprouted from the potting mix and hybrid soils. Even replacing just 25 percent of the simulant with potting mix helped heaps, they found.

The researchers also tried growing rice in soil with added perchlorate. They sourced one wild rice variety and two cultivars with a genetic mutation — modified for resilience against environmental stressors like drought — and grew them in Mars-like dirt with and without perchlorate (SN: 9/24/21).

No rice plants grew amid a concentration of 3 grams of perchlorate per kilogram of soil. But when the concentration was just 1 gram per kilogram, one of the mutant lines grew both a shoot and a root, while the wild variety managed to grow a root.

The findings suggest that by tinkering with the successful mutant’s modified gene, SnRK1a, humans might eventually be able to develop a rice cultivar suitable for Mars.