10. ANOMALOCARIS (~ 525 Ma) This one metre long invertebrate surely deserves to be included on the list, being one of the first complex oceanic predators to ever have existed. Anomalocaris stalked the Cambrian oceans, viewing the world with a deadly new evolutionary innovation - eyes. Complex eyes allowed this creature to storm its way to the top of the food chain, and with powerful appendages covered in spines it had no trouble devouring prey with tough carapaces. Whilst Anomalocaris is dwarfed by the other contenders on this list, it was still over 10 times larger than any other animal of its time.
9. KRONOSAURUS (125-99 Ma) Kronosaurus, a Cretaceous mosasaur, is named after the Greek titan, Cronus. Its name is well deserved as this ancient beast was a remarkably powerful being. Kronosaurus could reach up to 10 metres long and had a mouth full of sharp, conical teeth. Unlike most other mosasaurs its tail was relatively short, however, evidence shows that Kronosaurus has immensely powerful fins and a pectoral girdle making it an impressive swimmer and hunter.
8. HELICOPRION (290-250 Ma) Helicoprion has astounded scientists since its discovery over 100 years ago. It is iconic for its bizarre spiral of teeth, there are still debates on where exactly these teeth where on the shark with proposals stating they were inside the mouth, on the tip of the tail, the dorsal fin or hanging under the jaw. The most commonly accepted location of the teeth is inside the lower jaw enabling Helicoprion to cleanly slice its prey into pieces.
7. XIPHACTINUS (~110-70 Ma) Xiphactinus was an extraordinary fish that lived during the Cretaceous. It was an esteemed predator that could reach an incredible 6 metres in length and specimens are renowned for their stunning preservation. One such example was 4 metres long and found with another exceptionally well preserved fish just short of 2 metres inside it implying that this particular Xiphactinus individual died shortly after its last feast. Xiphactinus had immensely sharp, slim teeth and an unmistakable underbite which was a possible aid when snaring creatures from below.
6. TYLOSAURUS (86-75 Ma) Tylosaurus is considered a mosasaur and was a vivacious predator all be it smaller than its relative Mosasaurus. Tylosaurus could reach up to 15 metres in length and was one of the apex predators of its day. Fossilised stomach contents of Tylosaurus contain fish, sharks, turtles and other marine reptiles. Despite having an impressive set of teeth, the frontal areas of the jaws exhibit a large reduction in tooth size as well as a more heavily reinforced snout in comparison to other mosasaurs suggesting that Tylosaurus may have rammed into victims with immense force damaging prey internally.
5. MOSASAURUS (70-66 Ma) The mosasaurs ruled the Cretaceous oceans and Mosasaurus was no exception. It could reach up to 17 metres long, longer than most other mosasaurs. Mosasaurus had a strong jaw packed with numerous conical teeth, bite marks of which have been found in huge prehistoric turtles and ammonites suggesting that Mosasaurus was a formidable hunter capable of catching large prey. Mosasaurus was a profound swimmer with strong paddle-like limbs and a huge tail capable of rapidly accelerating the animal when required.
4. DUNKLEOSTEUS (382-358 Ma) Dunkleosteus terrorised the oceans around 370 million years ago and was part of a dynasty known as the placoderm fish (meaning armoured). Dunkleosteus could reach a whopping 6-10 metres in length and probably weighed over a ton. The skull was made up of huge, solid bony plates giving unrivalled protection allowing them to dominate the oceans. Placoderm fish were some of the first organisms to have a mobile jaw, as can be seen in Dunkleosteus’ impressive shearing plates which were used to slice cleanly through prey. Despite an revolutionary jaw, Dunkleosteus could not chew and several fossilised regurgitated remains of its meals have been found that the giant fish simply could not stomach.
3. DAKOSAURUS (157-137 Ma) Dakosaurus was the largest of a group of marine reptiles that were distant relatives of crocodiles. Dakosaurus could reach up to 5 metres long and had a streamlined body with large paddle-like fins and a long muscular tail implying that is was a very efficient swimmer. The diet of Dakosaurus consisted mostly of fish. The teeth of Dakosaurus are lateromedially compressed and serrated which is a similar morphology to modern killer whales indicating that Dakosaurus was an apex predator of the Jurassic oceans. Skull fenestrae provides evidence that Dakosaurus had very large adductor muscles (which are responsible for the jaw closing) and so it was certainly capable of a forceful bite.
2. LIOPLEURODON (160-155 Ma) Liopleurodon stormed the Jurassic oceans, its huge 7 metre long frame effortlessly cruised through the water. The skull itself could reach a massive 1.5 metres long with a jaw that was packed with teeth up to 10cm long and was capable of an immense bone-crushing force. Liopleurodon was a remarkable hunter with the ability to swim with its nostrils open and so could use its powerful sense of smell to track prey from afar, much like sharks do. Liopleurodon most likely had good camouflage such as a lighter underside and a darker topside so it would blend in with the water to prey above and below.
1. MEGALODON (~16-2.6 Ma) Megalodon rightfully deserves the top position of the greatest prehistoric ocean predators, ruling the seas for an incredible 14 million years. Megalodon has been estimated to reach up to 18 metres in length and weighing over 40 tonnes. Megalodon is known for its huge 6 inch teeth which were serrated on both sides for an efficient slicing action. Fossils of Megalodon’s prey have also been found, the shark appeared to have adapted its hunting tactics for different sized prey; for smaller prey they would just use their bone crushing bite to pulverise internal organs, but for larger prey they would bite or rip flippers off of creatures to immobilise them and then go in for the kill. The exact bite force of Megalodon has been estimated at around 110,000 N which was more than enough to shatter even the most robust bones. The hunting methods of Megalodon will unfortunately remain a mystery but it was been hypothesised that they swam at great depths and used short bursts of speed to swim up and tear into their preys vulnerable underbelly. Sharks have existed for over 420 million years and still continue to be some of the most successful predators alive, Megalodon is a perfect example of how deadly they can be.
yeswe_travel
Look how littel I am, next to this massive mountain..
Can you see the beauty around me ✨ .
DE)
– Earl Maize, its project engineer @ JPL
current mood: emotional about a space probe
Cassini is the first spacecraft that was destroyed not from malfunction, or as a necessary end result of its mission… but out of love.
The probe was running out of propulsion fuel, but there’s no reason it couldn’t have been pushed into a stable orbit from where it could collect data and send back pictures for a long while yet.
Except it had detected that one of Saturn’s moons held liquid water and organic compounds: a world that might support life. A world that is, at the least, dreaming of life.
There is no orbit stable enough to be certain that the probe, carrying radioactive batteries and Earth’s bacteria, would never have come into contact with Enceladus. A delicate island of alien life could have been snuffed out or overrun. The sheep could have eaten the rose.
So instead - for the love of this fragile possibility, this potential that might yet never be realized - Cassini was brought into a final, intimate tango with Saturn.
But of course, all space probes are built for the sake of awe, which is nearly love. Science is rational, but scientists are driven to understand the universe just as the religious strive to know the face of God.
The Cassini probe was a 4 billion dollar machine for understanding Saturn. And yesterday, two decades after it launched from our planet, it was destroyed while sending us information about Saturn it never could have gathered from a distant, stable orbit: advancing its purpose, even though it would be consumed.
Here’s a great explanation of language usage in sci-fi literature for all those who cannot keep their nit-picking to themselves:
Kalgash is an alien world and it is not our intention to have you think that it is identical to Earth, even though we depict its people as speaking a language that you can understand, and using terms that are familiar to you. Those words should be understood as mere equivalents of alien terms-that is, a conventional set of equivalents of the same sort that a writer of novels uses when he has foreign characters speaking with each other in their own language but nevertheless transcribes their words in the language of the reader. So when the people of Kalgash speak of “miles,” or “hands,” or “cars,” or “computers,” they mean their own units of distance, their own grasping-organs, their own ground-transportation devices, their own information-processing machines, etc. The computers used on Kalgash are not necessarily compatible with the ones used in New York or London or Stockholm, and the “mile” that we use in this book is not necessarily the American unit of 5,280 feet. But it seemed simpler and more desirable to use these familiar terms in describing events on this wholly alien world than it would have been to invent a long series of wholly Kalgashian terms.
In other words, we could have told you that one of our characters paused to strap on his quonglishes before setting out on a walk of seven vorks along the main gleebish of his native znoob, and everything might have seemed ever so much more thoroughly alien. But it would also have been ever so much more difficult to make sense out of what we were saying, and that did not seem useful. The essence of this story doesn’t lie in the quantity of bizarre terms we might have invented; it lies, rather, in the reaction of a group of people somewhat like ourselves, living on a world that is somewhat like ours in all but one highly significant detail, as they react to a challenging situation that is completely different from anything the people of Earth have ever had to deal with. Under the circumstances, it seemed to us better to tell you that someone put on his hiking boots before setting out on a seven-mile walk than to clutter the book with quonglishes, vorks, and gleebishes.
If you prefer, you can imagine that the text reads “vorks” wherever it says “miles,” “gliizbiiz” wherever it says “hours,” and “sleshtraps” where it says “eyes.” Or you can make up your own terms. Vorks or miles, it will make no difference when the Stars come out.
-I.A.
-R.S.
So I just discovered that the famous depth chart of Lake Baikal, you know, this one
Is
Uh
Not the whole picture
So this is going to haunt me forever
A giant #ammonite from millions of years ago. One of New Zealand’s largest fossils is on permanent display in Te Papa.
On Sept. 15, 2017, our Cassini spacecraft ended its epic exploration of Saturn with a planned dive into the planet’s atmosphere–sending back new science to the very last second. The spacecraft is gone, but the science continues!
New research emerging from the final orbits represents a huge leap forward in our understanding of the Saturn system – especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised. How did they form? What holds them in place? What are they made of?
Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings from Cassini’s Grand Finale. That’s when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.
Knowing Cassini’s days were numbered, its mission team went for gold. The spacecraft flew where it was never designed to fly. For the first time, it probed Saturn’s magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the engineering push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.
Many more Grand Finale science results are to come, but today’s highlights include:
Complex organic compounds embedded in water nanograins rain down from Saturn’s rings into its upper atmosphere. Scientists saw water and silicates, but they were surprised to see also methane, ammonia, carbon monoxide, nitrogen and carbon dioxide. The composition of organics is different from that found on moon Enceladus – and also different from those on moon Titan, meaning there are at least three distinct reservoirs of organic molecules in the Saturn system.
For the first time, Cassini saw up close how rings interact with the planet and observed inner-ring particles and gases falling directly into the atmosphere. Some particles take on electric charges and spiral along magnetic-field lines, falling into Saturn at higher latitudes – a phenomenon known as “ring rain.” But scientists were surprised to see that others are dragged quickly into Saturn at the equator. And it’s all falling out of the rings faster than scientists thought – as much as 10,000 kg of material per second.
Scientists were surprised to see what the material looks like in the gap between the rings and Saturn’s atmosphere. They knew that the particles throughout the rings ranged from large to small. They thought material in the gap would look the same. But the sampling showed mostly tiny, nanograin- and micron-sized particles, like smoke, telling us that some yet-unknown process is grinding up particles. What could it be? Future research into the final bits of data sent by Cassini may hold the answer.
Saturn and its rings are even more interconnected than scientists thought. Cassini revealed a previously unknown electric current system that connects the rings to the top of Saturn’s atmosphere.
Scientists discovered a new radiation belt around Saturn, close to the planet and composed of energetic particles. They found that while the belt actually intersects with the innermost ring, the ring is so tenuous that it doesn’t block the belt from forming.
Unlike every other planet with a magnetic field in our Solar System, Saturn’s magnetic field is almost completely aligned with its spin axis. Think of the planet and the magnetic field as completely separate things that are both spinning. Both have the same center point, but they each have their own axis about which they spin. But for Saturn the two axes are essentially the same – no other planet does that, and we did not think it was even possible for this to happen. This new data shows a magnetic-field tilt of less than 0.0095 degrees. (Earth’s magnetic field is tilted 11 degrees from its spin axis.) According to everything scientists know about how planetary magnetic fields are generated, Saturn should not have one. It’s a mystery physicists will be working to solve.
Cassini flew above Saturn’s magnetic poles, directly sampling regions where radio emissions are generated. The findings more than doubled the number of reported crossings of radio sources from the planet, one of the few non-terrestrial locations where scientists have been able to study a mechanism believed to operate throughout the universe. How are these signals generated? That’s still a mystery researchers are looking to uncover.
For the Cassini mission, the science rolling out from Grand Finale orbits confirms that the calculated risk of diving into the gap – skimming the upper atmosphere and skirting the edge of the inner rings – was worthwhile.
Almost everything going on in that region turned out to be a surprise, which was the importance of going there, to explore a place we’d never been before. And the expedition really paid off!
Analysis of Cassini data from the spacecraft’s instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.
To read the papers published in Science, visit: URL to papers
To learn more about the ground-breaking Cassini mission and its 13 years at Saturn, visit: https://www.nasa.gov/mission_pages/cassini/main/index.html
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Look at the bottom gif! The long tentacles are pushed out and parallel to each other while the jelly is motionless. This behavior is predatory, which means that the Marianas Trench Jelly is set in attack mode!
Read more about the 2016 discovery of the Marianas Trench Jelly
The word radio was coined in 1907 after a decade of furious activity to discover the mechanism for wireless transmission. A decade earlier, French physicist Édouard Branly coined the term radioconductor to describe a means of wireless transmission. He based his term on the verb radiate which ultimately came from the Latin word radius meaning the spoke of a wheel, a ray or beam of light. The word radio was first used by itself in a 1907 article by Lee De Forest. It was used five years later by the Navy to distinguish it from other wireless technologies and entered common usage in the next decade. Radio technology advanced so quickly that a little over 50 years later on November 16, 1974, scientists broadcast the first interstellar radio message out to the stars, a program that later became known as METI, the Message to Extra-terrestrial Intelligence. To date, only 9 messages have been transmitted by a variety of organizations:
{The Morse Message (1962)}
Arecibo message (1974)
Cosmic Call 1 (1999)
Teen Age Message (2001)
Cosmic Call 2 (2003)
Across the Universe (2008)
A Message From Earth (2008)
Hello From Earth (2009)
RuBisCo Stars (2009)
Wow! Reply (2012)
The first radio message, known as the Morse Message, does not technically belong on this list as the Russians directed the message to Venus, and thus the primary mission was not Interstellar. The message targets vary in distance from the very short (the majority of targets are under 100 light years away) to the very far, including the Arecibo Message, which targets the M13 globular cluster 24,000 light years away.
While there have been some dissenting voices who argue that ‘revealing’ our location to enemy or hostile alien civilizations is ill-advised at best, most scientific consensus agrees that due to the physical restrictions on speed and travel (as currently understood) we are in no danger of imminent attack. While the Arecibo Message won’t reach its target for another 25,000 years or so, the first of the other messages should arrive by 2029. Other scientist point out that our current terrestrial radio and television broadcasts represent their own METI signal and thus we have no need to fund additional broad- or narrow-cast messages.
Image of the Arecibo Radio Telescope courtesy Marius Strom under a Creative Commons 3.0 share alike license.
Image of the Arecibo Message of 1679 bits in the public domain.
Amateur astronomer, owns a telescope. This is a side blog to satiate my science-y cravings! I haven't yet mustered the courage to put up my personal astro-stuff here. Main blog : @an-abyss-called-life
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