Earth’s Temporary Moon

Earth has acquired a temporary moon. It has been tagging along with us for about 60 years and will continue to tag along until 2083. It is a small asteroid going by the name 2025 PN7.

Officially discovered by the University of Hawaii and confirmed this past week, it is what’s known as a “quasi-moon”—a rare celestial companion that travels almost exactly in sync with Earth. It’s not a true moon because it doesn’t orbit around the Earth. Right now, it is orbiting the sun, keeping pace with us so that it appears to shadow our planet.

2025 PN7 is estimated to be 18 to 36 meters wide, about the height of a small building, which is tiny by cosmic standards. That may be why it took so long to notice it.

Our real moon is held tight by gravity, but this asteroid isn’t bound to us. Think of it as a friendly jogger matching our stride on the same track—close enough to notice but never touching.

After 2083—if its current orbit holds that long—it will drift away into open space. At its closest approach to us, it gets within 4 million kilometers, which is roughly ten times the distance between Earth and the moon. At its most distant, it can swing out to 17 million kilometers. That changing distance is because of the competing gravity of the sun and various planets.

So far, astronomers have confirmed only eight quasi-moons. Each of them is a small but valuable clue in understanding how asteroids move and how Earth’s gravity shapes the space around us. These objects are more than curiosities. They help refine orbital models, improve predictions for near-Earth asteroids, and could serve as testing grounds for future missions. After all, they’re close, relatively stable, and reachable without traveling too far from home.

2025 PN7 will never outshine our real moon. But it’s there and worth knowing about.

 

https://www.msn.com/en-us/news/technology/nasa-confirms-earth-now-has-two-moons-until-2083/ar-AA1OQpRt?ocid=hpmsn&cvid=68f6da61133a4c1f869a4eb40f801f5c&ei=63

 

Oldest Gun Ever Found in America

From 1540 to 1542, Francisco Vázquez de Coronado led a Spanish expedition out of Mexico to as far north as Kansas in a search for the mythical Seven Cities of Gold. The golden cities were never found but during a stop at the former settlement of San Geronimo III (in what is now Nogales AZ) the expedition left some items behind. One of those items is now a major archaeological find and an indication of weapon history in the United States.

In 2020, Researchers uncovered a bronze cannon—also known as a “wall gun”—at a Spanish stone-and-adobe structure. Radiocarbon dating and other dating techniques say the device is 480-years-old, which puts it in the same time period as Coronado’s expedition. This cannon is the oldest firearm ever discovered within the continental United States, and perhaps is the oldest cannon known at this time on the continent.

However, it is not a small pistol. Being 42 inches in length and weighing 40 pounds, it would have taken two people to operate. The team also uncovered plenty of broken swords and daggers, fishhooks, pottery, and other items, but not any bullets. And the lack of residue in the barrel indicated it was never fired.

A wall gun is considered a beefed-up musket. It got its name because it was often used at a building’s wall or a ship’s railing. Although not what is usually visualized as a cannon, it is also referred to one because of the smoothbore barrel. This particular gun was likely built in the early 1500s in either Mexico or the Caribbean and brought on the expedition before it was eventually abandoned, possibly because they ran out of ammunition for it.

These Spanish explorers were the first Europeans to see the Grand Canyon.

Since the first gun’s discovery in 2020, the team has uncovered a second, very similar cannon.

 

https://www.msn.com/en-us/news/world/archaeologists-accidentally-discovered-the-oldest-gun-ever-found-in-america/ar-AA1On7iD?ocid=hpmsn&cvid=68eda03f62e4437c80d66c55b0ff381b&ei=107

7,000-Year-Old Mummies

The Sahara is a vast expanse of sand where the fight for survival can be brutal. But there was a time in the distant past when it was green and flourishing.

Back between 14,000 and 5,500 years ago, during the African Humid Period, the Sahara had enough water to support a way of life, rather than being one of the driest places on Earth. At that time, it was a savannah where early humans settled for the favorable farming conditions. Among those people was a mysterious sub-group who lived in what is now southwestern Libya. Genetically, they should have been Sub-Saharan. But modern analysis shows that their genes don’t reflect that.

A team of researchers found two 7,000-year-old naturally preserved mummies of Neolithic female herders at the Takarkori rock shelter. Usually, genetic material does not preserve well in arid conditions, but in this case, there was enough fragmented DNA to give some insights into their past and clear up some of the mystery of human populations in the Sahara.

The Takarkori individuals don’t share DNA with modern humans. The majority of their ancestry stems from a previously unknown North African genetic lineage that diverged from sub-Saharan African lineages about the same time as modern humans roamed outside of Africa. But the Takarkori people appear to have remained isolated throughout most of their existence.

These Takarkori individuals were close relatives of 15,000-year-old foragers from the Taforalt Cave in Morocco. Both the Takarkori and the Taforalt people have about the same genetic distance from Sub-Saharan groups that existed at that time. This suggests there was not much gene flow between Sub-Saharan and Northern Africa at the time. Also, the Taforalts have half the Neanderthal genes of non-Africans. The Takarkori have ten times less. But, both of them still have more Neanderthal DNA than other Sub-Saharan peoples who were around at the time. Although the Tarkarkori apparently had less contact with Neanderthals than their more western brethren, they must have had more contact than other groups in their region. There are also traces of evidence of the Tarkarkori mixing with farmers from the Levant (the east coast of the Mediterranean Sea). But otherwise, the genes of the Takarkori reveal they were mostly isolated. Although genetically close to Northwestern African foragers like the Taforalt, they were distinct from Sub-Saharan populations.

It appears there was not much genetic exchange in the Green Sahara during the African Humid Period. It was thought that farming spread through the region by migrations, but this research suggests another explanation. Perhaps pastoralism spread through cultural diffusion into a deeply divergent, isolated North African lineage that was widespread in Northern Africa during the late Pleistocene epoch. In other words, farming spread through the exchange of practices between cultures rather than the mixture of people from migrations.

The Takarkori may have inherited their genes from a hunter-gatherer group from before animals were domesticated and farming began. Despite being hunter-gatherers, their ancestors made advances in making pottery, baskets, and tools made of wood and bone. They also seemed to stay in one place for longer periods of time.

Possibly the Takarkori stayed isolated because of the diversity of environments in the Green Sahara. These ranged from lakes and wetlands to woodlands, grasslands, savannas and even mountains. Such differences were probably barriers to interactions between human groups.

Elsewhere in the Sahara, there might be additional mummies or artifacts that could tell us more about life in the desert before it dried out.

 

https://www.msn.com/en-us/news/technology/scientists-found-7-000-year-old-mummies-in-the-desert-that-don-t-share-dna-with-modern-humans/ar-AA1N0sir?ocid=hpmsn&cvid=68d560f961774dfd9a9711556f780d2a&ei=40

Circling Cyclones

Since we’re currently in hurricane season, it seems a good time to talk about hurricanes and cyclones. These types of weather systems don’t often find themselves in a traffic jam in Earth’s vast oceans, but when they do, there are consequences.

When two storms move too close together, they start to influence one another’s strength and track. This tropical tango is known as the Fujiwhara effect. That scenario played out this week when Hurricanes Imelda and Humberto danced together off the southeastern US coast.

After devastating the coast of North Carolina, Humberto moved out to sea, but as it did so, it tugged Imelda to go with it.

On Tuesday (9/30), they were both Category 1 hurricanes and they were within 467 miles of each other, which is the closest that two Atlantic hurricanes have come to each other in at least the past 60 years. Two hurricanes churning side-by-side is more common in the Pacific Ocean but rarely happens in the Atlantic.

The interactions during these events can vary greatly, which can make forecasting the tracks and intensity a challenge. Imelda’s track forecast changed dramatically after she was pulled away from the US and toward Bermuda.

Both hurricanes struggled in the face of the other’s wind shear, with Humberto weakening and finally dissipating Wednesday morning. After that, forecasters expect Imelda to hit Bermuda on Thursday as a Category 2.

In 1921, Japanese meteorologist Sakuhei Fujiwhara published a paper that said two storms spinning near each other could start rotating together around a common center point. He was right.

How close the storms need to be to trigger the Fujiwhara effect is dependent on the size of each storm. If two large storms—those that span hundreds of miles—get within about 850 miles of each other, they start to dance. The distance shrinks to 350 miles for smaller storms.

Closely matched storms will orbit around a common point but then go their separate ways. The circling tugs each storm off the path they would have taken. In 2017, Hilary and Irwin had this experience in the east Pacific. They were well matched. Both systems interacted for so long, they eventually dissipated around the same time.

But if one storm is much stronger than the other, the stronger one could consume the weaker one. In the west Pacific in 2022, the powerful typhoon Hinnamnor was headed for Taiwan before it met a tropical depression that was trying to grow. Hinnamnor and the depression rotated until the typhoon devoured the depression. Hinnamnor slowed and weakened for a bit, but when it restrengthened, it took a nearly 90-degree turn from its original track.

In a rare Fujiwhara scenario, two weak storms spinning together could merge and create a larger storm,

All of these potential interactions and outcomes pose an incredible forecasting challenge, even for computers. Any small changes in the strength or size of each storm, or slight deviation from the anticipated track throws a model’s complex calculations into chaos.

 

https://www.nola.com/news/hurricane/hurricanes-humberto-imelda-fujiwhara/article_14cec9cf-1c86-422c-983d-71b320682d2b.html

https://www.msn.com/en-us/weather/topstories/here-s-what-can-happen-when-two-hurricanes-get-too-close-together/ar-AA1NiXg4?ocid=hpmsn&cvid=68d5abc4f3d04d0b915ca4e4134e1350&ei=63