Libro de Visitas

Kevinblape

11 Apr 2025 - 10:41 pm

A long time in the making
Curiosity landed in Gale Crater on August 6, 2012. More than 12 years later, the rover has driven over 21 miles (34 kilometers) to ascend Mount Sharp, which is within the crater. The feature’s many layers preserve millions of years of geological history on Mars, showing how it shifted from a wet to a dry environment.
cbridge
Perhaps one of the most valuable samples Curiosity has gathered on its mission to understand whether Mars was ever habitable was collected in May 2013.

The rover drilled the Cumberland sample from an area within a crater called Yellowknife Bay, which resembled an ancient lake bed. The rocks from Yellowknife Bay so intrigued Curiosity’s science team that it had the rover drive in the opposite direction to collect samples from the area before heading to Mount Sharp.
Since collecting the Cumberland sample, Curiosity has used SAM to study it in a variety of ways, revealing that Yellowknife Bay was once the site of an ancient lake where clay minerals formed in water. The mudstone created an environment that could concentrate and preserve organic molecules and trapped them inside the fine grains of the sedimentary rock.

Freissinet helped lead a research team in 2015 that was able to identify organic molecules within the Cumberland sample.

The instrument detected an abundance of sulfur, which can be used to preserve organic molecules; nitrates, which are essential for plant and animal health on Earth; and methane composed of a type of carbon associated with biological processes on Earth.

“There is evidence that liquid water existed in Gale Crater for millions of years and probably much longer, which means there was enough time for life-forming chemistry to happen in these crater-lake environments on Mars,” said study coauthor Daniel Glavin, senior scientist for sample return at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.

Johnniefup

11 Apr 2025 - 10:04 pm

Curiosity rover makes ‘arguably the most exciting organic detection to date on Mars’
bungee exchange

The NASA Curiosity rover has detected the largest organic molecules found to date on Mars, opening a window into the red planet’s past. The newly detected compounds suggest complex organic chemistry may have occurred in the planet’s past — the kind necessary for the origin of life, according to new research.

The organic compounds, which include decane, undecane and dodecane, came to light after the rover analyzed a pulverized 3.7 billion-year-old rock sample using its onboard mini lab called SAM, short for Sample Analysis at Mars.

Scientists believe the long chains of molecules could be fragments of fatty acids, which are organic molecules that are chemical building blocks of life on Earth and help form cell membranes. But such compounds can also be formed without the presence of life, created when water interacts with minerals in hydrothermal vents.

The molecules cannot currently be confirmed as evidence of past life on the red planet, but they add to the growing list of compounds that robotic explorers have discovered on Mars in recent years. A study detailing the findings was published Monday in the journal Proceedings of the National Academy of Sciences.
The detection of the fragile molecules also encourages astrobiologists that if any biosignatures, or past signs of life, ever existed on Mars, they are likely still detectable despite the harsh solar radiation that has bombarded the planet for tens of millions of years.

“Ancient life, if it happened on Mars, it would have released some complex and fragile molecules,” said lead study author Dr. Caroline Freissinet, research scientist at the French National Centre for Scientific Research in the Laboratory for Atmospheres, Observations, and Space in Guyancourt, France. “And because now we know that Mars can preserve these complex and fragile molecules, it means that we could detect ancient life on Mars.”

Leonarditasp

11 Apr 2025 - 10:01 pm

Everyone is talking about Greenland. Here’s what it’s like to visit
cow swap

A few months ago, Greenland was quietly getting on with winter, as the territory slid deeper into the darkness that envelops the world’s northerly reaches at this time of year.

But President Donald Trump’s musings about America taking over this island of 56,000 largely Inuit people, halfway between New York and Moscow, has seen Greenland shaken from its frozen Arctic anonymity.

Denmark, for whom Greenland is an autonomous crown dependency, has protested it’s not for sale. Officials in Greenland, meanwhile, have sought to assert the territory’s right to independence.

The conversation continues to intensify. A contentious March 28 visit to a US military installation by Usha Vance, the second lady, accompanied by her husband, Vice President JD Vance, was the latest in a series of events to focus attention on Trump’s ambitions for Greenland.

The visit was originally planned as a cultural exchange, but was shortened following complaints from Greenland Prime Minister Mute B. Egede.

Had the Vances prolonged their scheduled brief visit, they would’ve discovered a ruggedly pristine wildernesses steeped in rich Indigenous culture.

An inhospitable icecap several miles deep covers 80% of Greenland, forcing the Inuit to dwell along the shorelines in brightly painted communities. Here, they spend brutally cold winters hunting seals on ice under the northern lights in near perpetual darkness. Although these days, they can also rely on community stores.

The problem for travelers over the years has been getting to Greenland via time-consuming indirect flights. That’s changing. Late in 2024, the capital Nuuk opened a long-delayed international airport. From June 2025, United Airlines will be operating a twice-weekly direct service from Newark to Nuuk.

Two further international airports are due to open by 2026 — Qaqortoq in South Greenland and more significantly in Ilulissat, the island’s only real tourism hotspot.

Jasoncax

11 Apr 2025 - 08:13 pm

Arctic auroras
ethena
For getting around during winter, the Inuit here nowadays prefer snowmobiles, although they still keep their sled dogs. During winter they’ll offer intrepid visitors, wrapped up warm against the deep-freeze temperatures, dog-sledding jaunts. These can last either an hour or be part of expeditions over several days, sometimes with the added experience of learning how to build an igloo. Sisimiut on the west coast and Tasilaq in the southeast are active winter centers for dog sledding.

Winter’s most stellar attraction, though, is northern lights watching. With little urban light pollution, Greenland is a dark canvas for spectacular displays, and aurora borealis-watching vacations are becoming more popular.

Staying outdoors, Greenland is developing a reputation among adventure enthusiasts: from long-distance skiing expeditions and heliskiing on the icecap to hiking the 100-mile-long Arctic Circle Trail from Kangerslussuaq, where firearms need to be carried for warning shots in case of polar bear encounters.

Life is definitely changing here. The climate crisis is eating away at its icecap and Greenland may well end up as a pawn in a game of geopolitical chess. But for now, the bright glare of international attention should shine a favorable light on one of the wildest travel destinations on Earth.

Travel writer Mark Stratton is an Arctic specialist who has traveled to Greenland six times and counting. He’s marveled at the aurora borealis, sailed to Disko Island, dog-sledded with the Inuit, and once got stuck in an icefloe.

Robertcef

11 Apr 2025 - 05:06 pm

‘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.”

Alonzowet

11 Apr 2025 - 05:03 pm

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.
kra cc
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.”

Andrereoge

11 Apr 2025 - 05:02 pm

Lunar clockwork
What scientists know for certain is that they need to get precision timekeeping instruments to the moon.
kra31cc
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.”)

Alonzostabs

11 Apr 2025 - 04:31 pm

Lunar clockwork
What scientists know for certain is that they need to get precision timekeeping instruments to the moon.
kraken даркнет
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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kraken зеркало
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.”)

Darnelldearo

11 Apr 2025 - 04:29 pm

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.
kraken тор
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.
https://kra30c.cc
kraken tor
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.”

Frankkeync

11 Apr 2025 - 03:14 pm

Lunar clockwork
What scientists know for certain is that they need to get precision timekeeping instruments to the moon.
кракен онион
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.”
https://kra30c.cc
кракен ссылка
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.”)