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• Comment Link Tuesday, 22 April 2025 10:43 AndrePat

  Lunar clockwork
  What scientists know for certain is that they need to get precision timekeeping instruments to the moon.
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  Exactly who pays for lunar clocks, which type of clocks will go, and where they’ll be positioned are all questions that remain up in the air, Gramling said.
  
  “We have to work all of this out,” she said. “I don’t think we know yet. I think it will be an amalgamation of several different things.”
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  Atomic clocks, Gramling noted, are great for long-term stability, and crystal oscillators have an advantage for short-term stability.
  “You never trust one clock,” Gramling added. “And you never trust two clocks.”
  
  Clocks of various types could be placed inside satellites that orbit the moon or perhaps at the precise locations on the lunar surface that astronauts will one day visit.
  
  As for price, an atomic clock worthy of space travel could cost around a few million dollars, according Gramling, with crystal oscillators coming in substantially cheaper.
  
  But, Patla said, you get what you pay for.
  
  “The very cheap oscillators may be off by milliseconds or even 10s of milliseconds,” he added. “And that is important because for navigation purposes — we need to have the clocks synchronized to 10s of nanoseconds.”
  
  A network of clocks on the moon could work in concert to inform the new lunar time scale, just as atomic clocks do for UTC on Earth.
  
  (There will not, Gramling added, be different time zones on the moon. “There have been conversations about creating different zones, with the answer: ‘No,’” she said. “But that could change in the future.”)
• Comment Link Tuesday, 22 April 2025 09:33 GordonCar

  ‘A whole different mindset’
  Accurate clockwork is one matter. But how future astronauts living and working on the lunar surface will experience time is a different question entirely.
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  On Earth, our sense of one day is governed by the fact that the planet completes one rotation every 24 hours, giving most locations a consistent cycle of daylight and darkened nights. On the moon, however, the equator receives roughly 14 days of sunlight followed by 14 days of darkness.
  
  “It’s just a very, very different concept” on the moon, Betts said. “And (NASA is) talking about landing astronauts in the very interesting south polar region (of the moon), where you have permanently lit and permanently shadowed areas. So, that’s a whole other set of confusion.”
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  “It’ll be challenging” for those astronauts, Betts added. “It’s so different than Earth, and it’s just a whole different mindset.”
  
  That will be true no matter what time is displayed on the astronauts’ watches.
  
  Still, precision timekeeping matters — not just for the sake of scientifically understanding the passage of time on the moon but also for setting up all the infrastructure necessary to carry out missions.
  
  The beauty of creating a time scale from scratch, Gramling said, is that scientists can take everything they have learned about timekeeping on Earth and apply it to a new system on the moon.
  
  And if scientists can get it right on the moon, she added, they can get it right later down the road if NASA fulfills its goal of sending astronauts deeper into the solar system.
  
  “We are very much looking at executing this on the moon, learning what we can learn,” Gramling said, “so that we are prepared to do the same thing on Mars or other future bodies.”
• Comment Link Tuesday, 22 April 2025 08:49 Cbwazg

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• Comment Link Tuesday, 22 April 2025 07:13 JeffreyLex

  Lunar clockwork
  What scientists know for certain is that they need to get precision timekeeping instruments to the moon.
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  Exactly who pays for lunar clocks, which type of clocks will go, and where they’ll be positioned are all questions that remain up in the air, Gramling said.
  
  “We have to work all of this out,” she said. “I don’t think we know yet. I think it will be an amalgamation of several different things.”
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  Atomic clocks, Gramling noted, are great for long-term stability, and crystal oscillators have an advantage for short-term stability.
  “You never trust one clock,” Gramling added. “And you never trust two clocks.”
  
  Clocks of various types could be placed inside satellites that orbit the moon or perhaps at the precise locations on the lunar surface that astronauts will one day visit.
  
  As for price, an atomic clock worthy of space travel could cost around a few million dollars, according Gramling, with crystal oscillators coming in substantially cheaper.
  
  But, Patla said, you get what you pay for.
  
  “The very cheap oscillators may be off by milliseconds or even 10s of milliseconds,” he added. “And that is important because for navigation purposes — we need to have the clocks synchronized to 10s of nanoseconds.”
  
  A network of clocks on the moon could work in concert to inform the new lunar time scale, just as atomic clocks do for UTC on Earth.
  
  (There will not, Gramling added, be different time zones on the moon. “There have been conversations about creating different zones, with the answer: ‘No,’” she said. “But that could change in the future.”)
• Comment Link Tuesday, 22 April 2025 07:13 VirgilAlimi

  Space, time: The continual question
  If time moves differently on the peaks of mountains than the shores of the ocean, you can imagine that things get even more bizarre the farther away from Earth you travel.
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  To add more complication: Time also passes slower the faster a person or spacecraft is moving, according to Einstein’s theory of special relativity.
  
  Astronauts on the International Space Station, for example, are lucky, said Dr. Bijunath Patla, a theoretical physicist with the US National Institute of Standards and Technology, in a phone interview. Though the space station orbits about 200 miles (322 kilometers) above Earth’s surface, it also travels at high speeds — looping the planet 16 times per day — so the effects of relativity somewhat cancel each other out, Patla said. For that reason, astronauts on the orbiting laboratory can easily use Earth time to stay on schedule.
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  For other missions — it’s not so simple.
  
  Fortunately, scientists already have decades of experience contending with the complexities.
  
  Spacecraft, for example, are equipped with their own clocks called oscillators, Gramling said.
  
  “They maintain their own time,” Gramling said. “And most of our operations for spacecraft — even spacecraft that are all the way out at Pluto, or the Kuiper Belt, like New Horizons — (rely on) ground stations that are back on Earth. So everything they’re doing has to correlate with UTC.”
  But those spacecraft also rely on their own kept time, Gramling said. Vehicles exploring deep into the solar system, for example, have to know — based on their own time scale — when they are approaching a planet in case the spacecraft needs to use that planetary body for navigational purposes, she added.
  
  For 50 years, scientists have also been able to observe atomic clocks that are tucked aboard GPS satellites, which orbit Earth about 12,550 miles (20,200 kilometers) away — or about one-nineteenth the distance between our planet and the moon.
  
  Studying those clocks has given scientists a great starting point to begin extrapolating further as they set out to establish a new time scale for the moon, Patla said.
  
  “We can easily compare (GPS) clocks to clocks on the ground,” Patla said, adding that scientists have found a way to gently slow GPS clocks down, making them tick more in-line with Earth-bound clocks. “Obviously, it’s not as easy as it sounds, but it’s easier than making a mess.”
• Comment Link Tuesday, 22 April 2025 06:58 GabrielElapy

  Axolotl problems
  As Mexico City grew and became more industrialized, the need for water brought pumps and pipes to the lake, and eventually, “it was like a bad, smelly pond with rotten water,” Zambrano said. “All of our aquatic animals suffer with bad water quality, but amphibians suffer more because they have to breathe with the skin.”
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  To add to the axolotls’ problems, invasive fish species such as carp and tilapia were introduced to the lake, where they feed on axolotl eggs. And a 1985 earthquake in Mexico City displaced thousands of people, who found new homes in the area around the lake, further contributing to the destruction of the axolotls’ habitat.
  
  These combined threats have devastated axolotl populations. According to the International Union for Conservation of Nature, there are fewer than 100 adult axolotls left in the wild. The species is considered critically endangered.
  While the wild axolotls of Lake Xochimilco have dwindled to near-extinction, countless axolotls have been bred for scientific laboratories and the pet trade. “The axolotl essentially helped establish the field of experimental zoology,” Voss said.
  
  In 1864, a French army officer brought live axolotls back to Europe, where scientists were surprised to learn that the seemingly juvenile aquatic salamanders were capable of reproduction. Since then, scientists around the world have studied axolotls and their DNA to learn about the salamanders’ unusual metamorphosis (or lack thereof) as well as their ability to regrow injured body parts.
  In addition to their role in labs, axolotls have become popular in the exotic pet trade (though they are illegal to own in California, Maine, New Jersey and Washington, DC). However, the axolotls you might find at a pet shop are different from their wild relatives in Lake Xochimilco. Most wild axolotls are a dark grayish brown. The famous pink axolotls, as well as other color variants such as white, blue, yellow and black, are genetic anomalies that are rare in the wild but selectively bred for in the pet trade.
  
  What’s more, “most of the animals in the pet trade have a very small genetic variance,” Zambrano said. Pet axolotls tend to be inbred and lack the wide flow of different genes that makes up a healthy population in the wild. That means that the axolotl extinction crisis can’t simply be solved by dumping pet axolotls into Lake Xochimilco. (Plus, the pet axolotls likely wouldn’t fare well with the poor habitat conditions in the lake.)
  
  Fame and misfortune
  The difficulties that axolotls face in the wild are almost diametrically opposed to the fame they’ve found in recent years. Axolotls have captured the human imagination for centuries, as evidenced by their roles in Aztec religion and stories, but the early 21st century seems to be a high point for them. An axolotl graces the 50 peso bill. There are axolotl-inspired Pokemon, and Reddit commenters have noted that the character Toothless from the “How to Train Your Dragon” movie series is distinctly axolotl-like.
  
  The introduction of axolotls to Minecraft in 2021 neatly mapped onto an uptick in Google searches for the animals, and social media makes it easy for people to gain access to photos and videos of the salamanders, particularly the photogenic pink ones often kept as pets.
  
  The axolotl pet trade probably doesn’t directly harm the wild populations since wild salamanders aren’t being poached or taken from Lake Xochimilco. However, Zambrano said, axolotls’ ubiquity in pop culture and pet stores might make people assume that because axolotls “live in all the tanks around the world, they are not in danger.”
• Comment Link Tuesday, 22 April 2025 06:52 Gghlfj

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• Comment Link Tuesday, 22 April 2025 06:12 AllanBes

  Why axolotls seem to be everywhere — except in the one lake they call home
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  Scientist Dr. Randal Voss gets the occasional reminder that he’s working with a kind of superstar. When he does outreach events with his laboratory, he encounters people who are keen to meet his research subjects: aquatic salamanders called axolotls.
  
  The amphibians’ fans tell Voss that they know the animals from the internet, or from caricatures or stuffed animals, exclaiming, “‘They’re so adorable, we love them,’” said Voss, a professor of neuroscience at the University of Kentucky College of Medicine. “People are drawn to them.”
  
  Take one look at an axolotl, and it’s easy to see why it’s so popular. With their wide eyes, upturned mouths and pastel pink coloring, axolotls look cheerful and vaguely Muppet-like.
  
  They’ve skyrocketed in pop culture fame, in part thanks to the addition of axolotls to the video game Minecraft in 2021. These unusual salamanders are now found everywhere from Girl Scout patches to hot water bottles. But there’s more to axolotls than meets the eye: Their story is one of scientific discovery, exploitation of the natural world, and the work to rebuild humans’ connection with nature.
  
  A scientific mystery
  Axolotl is a word from Nahuatl, the Indigenous Mexican language spoken by the Aztecs and an estimated 1.5 million people today. The animals are named for the Aztec god Xolotl, who was said to transform into a salamander. The original Nahuatl pronunciation is “AH-show-LOAT”; in English, “ACK-suh-LAHT-uhl” is commonly used.
  Axolotls are members of a class of animals called amphibians, which also includes frogs. Amphibians lay their jelly-like eggs in water, and the eggs hatch into water-dwelling larval states. (In frogs, these larvae are called tadpoles.)
  
  Most amphibians, once they reach adulthood, are able to move to land. Since they breathe, in part, by absorbing oxygen through their moist skin, they tend to stay near water.
  
  Axolotls, however, never complete the metamorphosis to a land-dwelling adult form and spend their whole lives in the water.
  
  “They maintain their juvenile look throughout the course of their life,” Voss said. “They’re teenagers, at least in appearance, until they die.”
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• Comment Link Tuesday, 22 April 2025 04:56 BillyTub

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