For the Halloween month, Mars gets closer to Earth this week than it will be for another 15 years
https://www.sciencealert.com/mars-is-sup...w-to-watch
INTRO: Mars, our second closest cosmic cousin, has been in our collective imagination for decades. Between fantasies of martian visits and the promise of water under its icy surface, Mars doesn't need to do much to be in our collective good books. But very soon, Mars is not just going to be close to our hearts, but also nearest to our actual planet - a mere 62.1 million kilometres (38.6 million miles) away from Earth.
This is the closest it'll be for the next 15 years. And it means that stargazing is highly recommended as Mars will be bright, big and easy to see with or without a telescope. We'd recommend checking out a sky chart to work out where Mars will be in the night sky in your location so you can plan for the best viewing.
But the good news is, it'll be in a region of the night sky with very few stars, and if you're lucky, you should also be able to catch Jupiter and Saturn shining brightly closer to the horizon. The day we'll be the absolute closest to Mars is the 6 October, so get a move on. As you can see in this video below, Mars and Earth are both on slightly elliptical orbits, which means they can occasionally get very close to each other... (MORE) ... VIDEO: https://youtu.be/wwY4Q4q6Vdg
How Cannibalism in the Womb May Have Made Megalodon a Titanic Terror
https://www.smithsonianmag.com/science-n...180975969/
EXCERPT: . . . Today’s lamniform sharks reproduce in a particular way. “Lamniform sharks don’t lay their eggs outside of the body, but instead the eggs hatch inside the mother,” Shimada says. From there, the pups develop until they’re ready to leave the womb. And they’re hungry. The little sharks that hatch early often eat unhatched eggs, and sometimes even their hatched siblings. And being that megalodon was a lamniform shark, it’s likely that the prehistoric giant’s babies would have acted like their modern counterparts.
Drawing from the relationship between physiology and reproduction in modern sharks, Shimada and coauthors propose that cannibalism in utero may have pushed these sharks to turn up the internal heat. Giving birth to a small number of large offspring may have required that mother sharks consume a greater amount of food, which may have been an evolutionary nudge towards mesothermy, with the needs of the babies and mother sharks opening a new evolutionary pathway. “This new paper suggests that intrauterine cannibalism may have been another driving mechanism for the evolution of mesothermy,” Pimiento says.
The relationship between the two doesn’t always work in lockstep, though. Pimiento notes that some sharks, like the sand tiger shark, are not mesothermic but still have cannibalistic embryos. [...] While it’s energetically costly for a mother shark to raise large embryos, Shimada says, those big babies would already have an advantage of being born large enough to hunt and avoid the jaws of many other predators. Add to that the fact that the number and size of pups varied between individual sharks and natural selection had the raw materials for larger and larger sharks to make their mark on the ocean when there was enough food to support such predators.
The task at hand is to find the critical evidence. While paleontologists have yet to uncover direct evidence for how many pups megalodon had or how many were birthed at a time, some rare shark fossils have been found with embryos. It’s possible such a find could help provide just that much more context to how the largest meat-eating shark of all time came to be. As much as we’re fascinated with enormous, whale-crunching megalodon, the sought-after clues may lie with baby sharks that beat the odds before even being born... (MORE - details)
https://www.youtube-nocookie.com/embed/BTPcq2HczVY
https://www.sciencealert.com/mars-is-sup...w-to-watch
INTRO: Mars, our second closest cosmic cousin, has been in our collective imagination for decades. Between fantasies of martian visits and the promise of water under its icy surface, Mars doesn't need to do much to be in our collective good books. But very soon, Mars is not just going to be close to our hearts, but also nearest to our actual planet - a mere 62.1 million kilometres (38.6 million miles) away from Earth.
This is the closest it'll be for the next 15 years. And it means that stargazing is highly recommended as Mars will be bright, big and easy to see with or without a telescope. We'd recommend checking out a sky chart to work out where Mars will be in the night sky in your location so you can plan for the best viewing.
But the good news is, it'll be in a region of the night sky with very few stars, and if you're lucky, you should also be able to catch Jupiter and Saturn shining brightly closer to the horizon. The day we'll be the absolute closest to Mars is the 6 October, so get a move on. As you can see in this video below, Mars and Earth are both on slightly elliptical orbits, which means they can occasionally get very close to each other... (MORE) ... VIDEO: https://youtu.be/wwY4Q4q6Vdg
How Cannibalism in the Womb May Have Made Megalodon a Titanic Terror
https://www.smithsonianmag.com/science-n...180975969/
EXCERPT: . . . Today’s lamniform sharks reproduce in a particular way. “Lamniform sharks don’t lay their eggs outside of the body, but instead the eggs hatch inside the mother,” Shimada says. From there, the pups develop until they’re ready to leave the womb. And they’re hungry. The little sharks that hatch early often eat unhatched eggs, and sometimes even their hatched siblings. And being that megalodon was a lamniform shark, it’s likely that the prehistoric giant’s babies would have acted like their modern counterparts.
Drawing from the relationship between physiology and reproduction in modern sharks, Shimada and coauthors propose that cannibalism in utero may have pushed these sharks to turn up the internal heat. Giving birth to a small number of large offspring may have required that mother sharks consume a greater amount of food, which may have been an evolutionary nudge towards mesothermy, with the needs of the babies and mother sharks opening a new evolutionary pathway. “This new paper suggests that intrauterine cannibalism may have been another driving mechanism for the evolution of mesothermy,” Pimiento says.
The relationship between the two doesn’t always work in lockstep, though. Pimiento notes that some sharks, like the sand tiger shark, are not mesothermic but still have cannibalistic embryos. [...] While it’s energetically costly for a mother shark to raise large embryos, Shimada says, those big babies would already have an advantage of being born large enough to hunt and avoid the jaws of many other predators. Add to that the fact that the number and size of pups varied between individual sharks and natural selection had the raw materials for larger and larger sharks to make their mark on the ocean when there was enough food to support such predators.
The task at hand is to find the critical evidence. While paleontologists have yet to uncover direct evidence for how many pups megalodon had or how many were birthed at a time, some rare shark fossils have been found with embryos. It’s possible such a find could help provide just that much more context to how the largest meat-eating shark of all time came to be. As much as we’re fascinated with enormous, whale-crunching megalodon, the sought-after clues may lie with baby sharks that beat the odds before even being born... (MORE - details)