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There is a vast menagerie of potentially habitable worlds in the cosmos, which means the Universe could be home to a diversity of life beyond what we can imagine. Creatures built on silicon rather than carbon, or organisms that breathe hydrogen instead of oxygen. But regardless of how strange and wondrous alien life may be, it is still governed by the same chemistry as life on Earth, and that means it needs a chemical solvent.

On Earth that solvent is water (H2O). Water dissolves some molecules into solution, giving organisms access to a range of materials. Since it is a liquid, water also makes it easy for complex molecules to mix together and interact. Terrestrial life isn’t possible without the solvent and fluid properties of water, and since water is a common molecule in the Universe, its central role for life is not surprising. But are there other common molecules that could serve as the solvent of life? Could alien life arise on distant worlds without the need for water? That’s the question studied in a recent article on the arXiv.

The authors begin with four general conditions for life-friendly solvents: they must dissolve some molecules but not all; they must be able to play a role in the metabolism of living things; a wide range of complex organic molecules must be able to survive in the solvent; and it must commonly exist on certain rocky worlds for billions of years.

Of all the known common solvents, only water clearly satisfies all four conditions. Ammonia (NH4) satisfies the first three, but is unlikely to meet the fourth condition because it breaks down readily when exposed to ultraviolet light, and wherever ammonia is likely to survive water is likely as well. So while ammonia can play a role in life on other worlds, it isn’t likely to be the main solvent. There are two molecules, however, that come pretty close to water.

The first is concentrated sulfuric acid (H2SO4). Although it’s extremely dangerous to life on Earth, sulfuric acid satisfies three main conditions. What’s not known is whether a diverse range of organic molecules can exist within it. Like water, it can provide ions for the exchange of electric charge, and it can participate in the interactions of certain compounds such as aromatic molecules. But there is one molecule that comes even closer to the usefulness and abundance of water: carbon dioxide (CO2).

Carbon dioxide is quite common. The atmospheres of both Mars and Venus are composed mostly of CO2, and it is likely that most rocky exoplanets are rich in carbon dioxide. It isn’t a solvent in its gaseous state, so life on warm planets such as Earth would rely upon it. But more distant exoplanets such as a cold Venus might. Liquid CO2 is geologically stable and tolerates a wide range of organic molecules. What isn’t known is whether its solvent properties are suitable for complex metabolism. CO2 is a very benign solvent, so it may not stir the chemical pot enough for life to arise within it. But since it plays well with so many types of molecules, it might work in collaboration with other molecules to become a foundation for life. The authors conclude this is a topic worth further study.

On one level this work confirms what we’ve already known, that water is the most abundant and useful solvent for life. But it also raises interesting questions. Other common molecules come close, and they might work together to form a home for alien life. The seas of Titan, for example, are rich in hydrocarbons and other complex organic molecules. Cold exoplanet moons similar to Titan could have oceans of CO2, NH4, and H2O, each capable of serving part of the role that water does on Earth. There is still much we don’t understand about cryogenic chemistry on cold exoplanets. So while the waters of life are likely in the cosmos, the seas of life on some worlds could be much more exotic.

Reference: Bains, William, Janusz J. Petkowski, and Sara Seager. “Alternative solvents for life: framework for evaluation, current status and future research.” arXiv preprint arXiv:2401.07296 (2024).

The post Life on Earth Uses Water as a Solvent. What are Some Other Options for Life as We Don't Know it? appeared first on Universe Today.

Here’s an eight-minute clip from Bill Maher in which he touts a new rule: 2024 is supposed to be “The Year of Sanity”.

Maher gives several examples of pervasive insanity, the most prominent being the likely reelection of Trump as President.  He also mentions tolerance of shoplifting, pro-Palestinian activists, admiration for the Houthis, frantic rumors that Taylor Swift is gay, claims that men can get pregnant, recent laws preventing abortion of fetuses that won’t live, and sundry other insane things.

After hearing all this, I decided that Maher is right: we need a Year of Sanity. Will we get one? I’m not holding my breath.

h/t: Mary

Interview with Robert Sapolsky; News Items: Betavolt 50 Year Battery, Moon Landing Delayed, Cloned Monkeys, Converting CO2 into Carbon Nanofibers, Bad Fen Shui; Who's That Noisy; From TikTok: Jellyfish UFO; Science or Fiction

Last night we went to an unusual restaurant: Stand Up Kebab, located in South Davis. It’s open only on Friday and Saturday nights, and the rest of the time the owner runs a car-repair garage (attached to the restaurant) as well as a used-car lot.

It’s an unprepossessing place. You order outside and they bring you your food inside.

The long table below had three people who were either tired, drunk, or dead. They may have been workers at the garage, but they eventually returned to life and left.

But the food was good, and here’s what we ate.  Beers first, of course:Persian (Iranian) ones:

We started with an unusual Persian soup called Ash e Reshteh. I discovered the ingredients from Wikipedia:

Ash reshteh or ash-e-reshteh (Persian: آش رشته) is a type of āsh (Iranian thick soup) featuring reshteh (thin noodles) and kashk (a sour dairy product, made from cooked or dried yogurt) commonly made in Iran.

It was absolutely delicious:

This was followed by a typical Iranian meal: kebabs. We had both chicken kebabs and lamb/beef kebabs, served with sauce, pickle, and plenty of rice. I’m not sure why there was a pat of butter on my plate

Lamb and beef kebabs:

And for a postprandial treat, we repaired to a store in downtown Davis that sells boba tea and mochi donuts. We had green-tea donuts; specimen below:

These are photos taken by reader Rosemary, who lives in South Africa near Kruger National Park, and runs an organization (GMFER: Global March for Elephants and Rhinos) that protects the local wildlife by partnering with local communities to raise awareness about trafficking in animals and poaching. GMFER also works to change laws to lessen poaching of elephants and rhinos and, mainly, to end trophy hunting of “iconic” animals.  Finally, they concentrate on educating children and rangers to appreciate local wildlife and the need to protect it, and teaching them to remove snares.

Rosemary has kindly helped me make arrangements for my visit to Kruger and environs in August; these arrangements can be quite complicated.

I’ll be in South Africa (Capetown and the Kruger area) for roughly a month. When I’m not traveling or staying in wildlife camps, I will be putting up in the small town of Hoedspruit near Kruger—in the house of Rosemary’s landlady.  Since the animals roam fairly freely around that area, which is in a fenced wildlife estate, that house is visited daily by common warthogs (Phacochoerus africanus), who come by for handouts of corn.  (Sometimes leopards also appear.)

One of the hogs is a huge and magnificent male whom I’ve named Ozymandias—Ozy for short.  Here he is; isn’t he gorgeous? (Photos by Rosemary).

The “warts” are protuberances formed from cartilage, and are presumably used to protect the animal’s head. They are sexually dimorphic.  The Fresno Chaffee Zoo describes them:

Males have 3 pairs of “warts,” 1 near the eyes, 1 on the snout and 1 pair on the lower jaw. The female’s two pair of warts are smaller, with none on the snout. The eyes are set high on the head. They have a typical pig’s disc-like nose pad.

Warthogs are underrated, and don’t count as one of the “Big Five” animals that tourists come to Africa to see. But they should be, as they are amazing animals.  They have four tusks, which are simply overgrown teeth, and these are used for fighting, excavating their burrows, and digging for roots (warthogs are grazing herbivores).

The lower pair of tusks become razor sharp by rubbing against the upper pair, and, besides digging, are used for fighting, particularly between males.  I would like to pet Ozy when I meet him, but I cannot as there’s a danger of being slashed!

The hogs are poached for their tusks, which are considered analogous to elephant ivory, and are also sometimes hunted as “trophies” (I despise this practice).

Warthogs are fearless animals, and mothers will defend their babies vigorously. Below is a YouTube video showing a family being stalked by wild dogs, but the mother drives them off. Then a single warthog baby gets attacked by lions, and even gets picked up in their mouths, but then recovers, goes to ground, and, despite its tiny size, goes after the lions and drives them off!

Note the speed of the mother, and the fact that warthogs run with their tails held vertically:

And an adult escaping lions, one of their most common predators.

Warthogs can run fast: up to 30 mph (48 kph), and they forage by grazing on their knees, as is in this Wikipedia picture (they drink the same way).

This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.

Here’s Ozy again in all his glory. When he arrives for a snack, all the other warthogs, including smaller males, females, and babies, leave him alone.  With one shake of his head they know they must stay away (photo by Rosemary):

Warthogs like to bathe and wallow in mud to cool themselves. But they also have a unique symbiotic relationship with mongeese. I was stunned when I saw this video of a warthog letting mongeese crawl all over it to remove its ticks. This of course is a symbiotic relationship: the mongeese get a meal and the pig gets cleaned (it’s similar to the cleaner wrasses in the ocean):

Rosemary’s landlady has built a cement pond in her yard for the warthogs to lie in. But a big male like Ozy will drive the other hogs out of the water and mud, so they have to wait for their bath.

Ozy again, photo by Rosemary:

I have made a deal to adopt Ozy. In return for paying a monthly fee to support him as well as other animals in the area, I will ensure that Ozy will get extra food, including vegetables, and I will get photos and a monthly letter from Ozy giving me an update on his doings.

One problem with Ozy is that, according to Rosemary, he is a Republican. He likes Trump because, like Ozy, Trump is a bully. Also, Ozy is keenly aware that there are two sexes, of which he’s one stupendous example, and he doesn’t like the Biden administration’s weakness for the “sex spectrum” argument. Here he is wearing his MAGA hat. But I will help take care of him anyway:

Stay tuned for more on Ozy. He hurt his leg, presumably in a fight with another male, and it is healing, but taking a while to do so.