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This ancient 'worm' may be forerunner to most animals — including us – CBC.ca

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A worm-like creature smaller than a grain of rice that burrowed on the seafloor in search of meals like dead organic matter about 555 million years ago may be the evolutionary forerunner of most animals living today — including people.

Scientists on Monday announced the discovery in the Australian outback of fossils of this creature, named Ikaria wariootia, that represents one of the most important primordial animals ever found.

It appears to be the earliest-known member of the vast animal group called bilaterians — organisms with two symmetrical sides, a front and back, with a mouth and an anus and a gut connecting them to process food, said paleontologist and study lead author Scott Evans of the Smithsonian Institution’s National Museum of Natural History in Washington.

The advent of such a body plan during the Ediacaran Period was a pivotal moment in life’s evolution on Earth, paving the way for more advanced bilaterians such as fish, amphibians, reptiles, birds, mammals, starfish, mollusks, insects and more. The few non-bilaterian animals include sponges, corals, sea anemones and jellyfish.

This rock shows three specimens of Ikaria wariootia from Nilpena. In total, the researchers identified the fossils showing the outside of the body of 118 Ikaria individuals using sophisticated scanning technology under a grant from NASA. (Scott D. Evans)

Up to six millimetres long, Ikaria had a worm-like appearance, though one end was larger than the other. Its discovery underscores the humble evolutionary beginnings of this large segment of the animal kingdom, humankind included, the researchers said.

“The origin and early evolution of bilaterians is a huge question for evolutionary biologists and paleobiologists because, of course, we are bilaterians. It is a natural instinct to want to know — when did our ancestors first appear and what did they look like,” said Mary Droser, a University of California Riverside geology professor and co-author of the study.

Lived alongside Dickinsonia

The researchers identified the fossils showing the outside of the body of 118 Ikaria individuals using sophisticated scanning technology under a grant from NASA. Ikaria’s fossils were associated with thousands of burrows previously found in South Australia state.

“It had been predicted that something like this should exist based on the burrows it left and from genetic studies of modern animals,” Evans said.

Dickinsonia fossils, found in Australia and Russia, range in size from a fingernail to some 1.22 metres (4½ feet) long. These animals lived at about the same time as Ikaria. (Australian National University)

Ikaria — meaning “meeting place” in a local Australian indigenous language — lived alongside another scientifically important primitive animal called Dickinsonia, which was much bigger and shaped vaguely like a lily pad but was not a bilaterian and is considered an evolutionary dead end.

Though none of its organs are known, a previous study of its burrows, led by co-author Jim Gehling of the South Australia Museum, indicated Ikaria used muscles to push through the sediment in a shallow marine environment to scavenge for nourishment in the form of dead organic matter including Dickinsonia corpses.

The research was published in the journal Proceedings of the National Academy of Sciences.

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Voyager 2 flew through a giant magnetic gas bubble during Uranus flyby – The Weather Network

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When NASA’s Voyager 2 spacecraft flew past Uranus in January of 1986, it gave us our first up-close look at the distant ice giant. Now, over three decades later, the data collected by the probe’s sensors has revealed that it flew straight through an immense magnetic bubble, known as a plasmoid, that was ejected from the planet’s atmosphere.

Uranus is certainly the oddball of all the worlds orbiting our Sun.

Tilted over on its side by some cataclysmic event in the early years of the solar system, this ice giant has a bizarre ‘wobbly’ magnetic field that scientists are still trying to make sense of, even now.

“The structure, the way that it moves… Uranus is really on its own,” Gina DiBraccio, a space physicist at NASA’s Goddard Space Flight Center and project scientist for the MAVEN mission, said in a press release.

Roughly 34 years ago, Voyager 2 discovered rings around Uranus, found never-before-seen moons circling it, and it took readings of the planet’s extremely frigid atmosphere.

Voyager 2 flies past Uranus on January 24, 1986. Credit: NASA/JPL-Caltech

According to a new study, data from Voyager 2’s flyby also picked up one other thing, which was missed at the time.

DiBraccio and fellow NASA Goddard scientist Dan Gershman were in the midst of planning possible missions for NASA to revisit the Ice Giant planets, Uranus and Neptune, but to stay this time. One aspect of this process is to look for compelling mysteries that a planetary spacecraft could investigate and potentially solve. Poring through the data collected by Voyager 2’s Magnetometer instrument, over three decades ago, they found something interesting.

As the spacecraft swung by, at around 80,000 km above Uranus’ cloudtops, it picked up a weird magnetic blip that lasted for just one minute of the total 45-hour flyby.

Voyager-Uranus-magnetometer-NASAMagnetometer data from Voyager 2’s Uranus flyby, showing the data averaged over 8-minute periods (red), and the same data plotted every 1.92 seconds (black), revealing the zigzag signature of a ‘plasmoid’. Credits: NASA/Dan Gershman

After examining this blip closely, DiBraccio and Gershman came to the conclusion that it was a ‘plasmoid’ – an immense magnetic bubble being expelled from Uranus’ magnetic field.

A plasmoid often forms as a planet’s magnetic field is shaped by the solar wind, and influenced by solar storms. While the magnetic field lines near to the planet form a fairly spherical ‘shield’, the flow of the solar wind causes the outer field lines to stretch back into a ‘magnetotail’ on the night side the planet. If a solar storm or a fast stream of the solar wind pushes the field lines in the magnetotail closer together, they can ‘reconnect’, closing off a magnetic bubble that then gets caught up in the solar wind’s flow.

Plasmoid-Earth-Reconnection-NASA-GoddardMagnetic reconnection in Earth’s magnetotail forms a plasmoid bubble. Credit: NASA’s Scientific Visualization Studio/Scott Sutherland

Based on what Voyager 2’s Magnetometer picked up, the spacecraft apparently passed straight through one of these plasmoids as it was passing Uranus. At roughly 400,000 kilometres wide, this magnetic bubble was found to be filled with mostly ionized hydrogen. There was a bonus, too. The magnetic field inside the bubble was found to form smooth, closed loops. This told DiBraccio and Gershman that the ionized hydrogen was very likely a blob of Uranus’ atmosphere, being carried away by the plasmoid.

While plasmoids are known to form in Earth’s magnetotail, and they’ve been observed at Mercury, Jupiter and Saturn, this is the very first evidence that this process happens at Uranus too.

Currently, there is great interest in the space exploration community to send new missions out to the Ice Giants, as we have with the Gas Giants, Jupiter and Saturn. After Voyager 1 & 2’s flybys of the outer planets, NASA sent Galileo, and then Juno, to orbit Jupiter. Cassini explored Saturn, and its rings and moons, for over 14 years.

Sending spacecraft to Uranus and Neptune would give us new up-close looks at these distant worlds. It would provide new data that could help scientists solve existing mysteries that were discovered, either by telescopes or the Voyager probes. It would undoubtedly give us new mysteries to study, about the Ice Giants themselves and about our solar system in general.

Sources: NASA | NASA’s Scientific Visualization Studio

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Comet makes northern hemisphere flyby | Star News – Otago Daily Times

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By David Hill

Canterbury’s observatories might be in lockdown, but there is plenty for budding scientists and the superstitious to discover.

While the Oxford Area School Observatory is in lockdown, volunteer Erik Vermaat has been keeping in touch his night class students via his “Corona Blog” and on Facebook.

He says a lockdown can be the ideal time to make new discoveries.

“Newton developed theories of calculus and gravity while at home. What are you doing?” Erik says.

As Erik points out, during the Great Plague of London in 1666, a 22-year-old Cambridge University student named Isaac Newton came up with new theories for calculus, optics and the law of gravitation, while in self-isolation after returning home to the family farm.

The superstitious will realise comets have a knack of making an appearance in the night sky in a crisis and Covid-19 doesn’t disappoint, as Oxford Observatory volunteer James Moffat points out.

“Atlas C/2019 Y4 could almost be mistaken for the latest doomsday comet arriving around the same time Covid-19 made its first appearance in China.”

Comets have historically been “harbingers of death”, with Halley’s Comet making one of its flybys in 1665, on the eve of the Great Plague which claimed 100,000 lives in London.

“This comet (Atlas) is fast living up to that reputation appearing in brightness as rapidly as the Covid-19 virus itself spreads.”

The Greek demi-god Atlas was perceived as carrying the weight of the world on his shoulders, “but in fact it was the celestial sphere not the terrestrial globe,” James says.

“That is a weight human-kind now bears upon his own shoulders in containing Covid-19.”

On Erik’s “Corona Blog” you can discover just how fast the speed of light is, all the observable parts of the electro-magnetic spectrum (which Ernest Rutherford helped to discover) and exoplanets. Find the link on the Oxford Observatory page on Facebook.

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Comet of a generation set to light up the night sky – The Times

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A comet speeding towards the inner solar system could become one of the brightest objects in the night sky, promising the most dramatic display of its kind in decades.

Astronomers believe that Comet Atlas, which in one month has grown 4,000 times brighter than when it was first spotted, has the potential to become “the comet of a generation” if it maintains its composition.

“It’s definitely a promising comet,” Daniel Brown, an astronomy expert at Nottingham Trent University, said yesterday.

“It’s pushing towards a level that by the end of April could look really, really stunning.”

The comet was discovered by astronomers at the Asteroid Terrestrial-impact Last Alert System (Atlas) at the University of Hawaii, which scans the sky for near-Earth objects and calculates whether

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