Scientists have discovered our earliest common ancestor — and the earliest ancestor of all animal life.

The honor goes to a minuscule worm-like creature that lived on the seafloor 555 million years ago. Researchers led by geologists at the University of California (UC) Riverside have identified it as the first known bilaterian, an organism with a front and back, symmetrical sides and front and back openings with a gut in between.

"It's the oldest fossil we get with this type of complexity," UC Riverside geology professor Mary Droser said in a press release.

Bilaterians are an important piece of the evolutionary tree that branches out to include the full diversity of animal life. The new body structure allowed creatures to move forward purposefully.

The fossil was dated to the Ediacaran Period 555 million years ago, when multi-celled, complex lifeforms began to emerge. But other fossils found in the "Ediacaran Biota" are not directly related to today's animals. These include Dickinsonia, organisms shaped like lily pads that have no mouth or gut, according to UC Riverside.

Geologists thought that bilaterians must have been alive during this period, but direct fossil evidence was hard to find. Researchers had thought for 15 years that these creatures were the explanation for fossilized burrows found in Ediacaran deposits in Nilpena, South Australia, but there was no definitive proof.

Then, Droser and UC Riverside doctoral graduate Scott Evans honed in on barely discernible oval impressions near the ends of the burrows. They used a three-dimensional scanner to fill in the impression and a body emerged — a grain-of-rice sized cylindrical creature about 2-7 millimeters long and about 1-2.5 millimeters wide.

"Once we had the 3D scans, we knew that we had made an important discovery," Evans said in the press release.

Scientists called the creature Ikaria wariootia and introduced it to the world in an article published in Proceedings of the National Academy of Sciences Monday. The name comes from the language of the Adnyamathanha people, an aboriginal group who live in the part of Australia where the fossil was found. Ikaria means "meeting place" and Warioota is the name of a local creek.

But the creature didn't live by the riverside. Instead, it spent its life burrowing in sand on the ocean floor in search of food.

The creature is also important for another reason. Evolutionary biologists had long predicted early bilaterians would be small and simple like Ikaria wariootia, according to the press release.

"This is what evolutionary biologists predicted," Droser said. "It's really exciting that what we have found lines up so neatly with their prediction."

The ozone layer above Antarctica has recovered so much, it's actually stopped many worrying changes in the Southern Hemisphere's atmosphere. If you're looking for someone to thank, try the world at large.

A new study suggests the Montreal Protocol - the 1987 agreement to stop producing ozone depleting substances (ODSs) - could be responsible for pausing, or even reversing, some troubling changes in air currents around the Southern Hemisphere.

Swirling towards our planet's poles at a high altitude are fast air currents known as jet streams. Before the turn of the century, ozone depletion had been driving the southern jet stream further south than usual. This ended up changing rainfall patterns, and potentially ocean currents as well.

Then, a decade or so after the protocol was signed, that migration suddenly stopped. Was it a coincidence?

Using a range of models and computer simulations, researchers have now shown this pause in movement was not driven by natural shifts in winds alone. Instead, only changes in the ozone could explain why the creep of the jet stream had suddenly stopped.

In other words, the impact of the Montreal Protocol appears to have paused, or even slightly reversed, the southern migration of the jet stream. And for once, that's actually good news.

In Australia, for instance, changes to the jet stream have increased the risk of drought by pushing rain away from coastal areas. If the trend does reverse, those rains might return.

"The 'weather bands' that bring our cold fronts have been narrowing towards the south pole, and that's why southern Australia has experienced decreasing rainfall over the last thirty years or so," says Ian Rae, organic chemist from the University of Melbourne who was not involved in the study.

"If the ozone layer is recovering, and the circulation is moving north, that's good news on two fronts (pun not intended)."

Still, we may not be celebrating for long. While improvements in cutting back our reliance on ODSs have certainly allowed the ozone to recover somewhat, carbon dioxide levels continue to creep upwards and place all that progress at risk.

Last year, the Antarctic ozone hole hit its smallest annual peak on record since 1982, but the problem isn't solved, and this record may have something to do with unusually mild temperatures in that layer of the atmosphere.

What's more, in recent years, there's been a surge in ozone-depleting chemicals, coming from industrial regions in China.

"We term this a 'pause' because the poleward circulation trends might resume, stay flat, or reverse," says atmospheric chemist Antara Banerjee from the University of Colorado Boulder.

"It's the tug of war between the opposing effects of ozone recovery and rising greenhouse gases that will determine future trends."

The Montreal Protocol is proof that if we take global and immediate action we can help pause or even reverse some of the damage we've started. Yet even now, the steady rise in greenhouse gas emissions is a reminder that one such action is simply not enough.

The Japan Aerospace Exploration Agency's Hayabusa2 spacecraft fired a copper cannonball a little bigger than a tennis ball into a near-Earth asteroid named Ryugu to learn about its composition.

Almost a year later, scientists have had a chance to analyze the data, captured by cameras on the spacecraft, to learn more about this asteroid some 195 million miles away.

The Hayabusa2 probe deployed Small Carry-on Impactor -- a device packed with plastic explosives -- intended to blast an artificial crater in the asteroid.

After deploying the SCI from the asteroid's orbit, Hayabusa2 moved to a safe distance from the blast site, according to the agency.

It also released a small camera called DCAM3 to capture the detonation as it occurred. The camera floated about a half mile away.

The researchers now know that the impact created a nearly 33-foot-wide crater on the surface of the asteroid, according to a new study. It sent up a plume of material upon impact, which the camera was able to capture in detail.

The study published in the journal Science on Thursday. An additional study about the asteroid's composition published Monday in the journal Nature.

The crater left behind is like a semicircle, including an elevated rim, a central pit and an asymmetrical pattern of ejected material, according to the researchers. They believe the asymmetric pattern could be due to a larger boulder beneath the crater.

Based on the material released by the impact, the researchers also believe that Ryugu includes material similar to loose sand on Earth.

The ejecta curtain, or plume of material created by the impact, never fully detached from the surface, according to the study. The researchers think that this was due to the asteroid's gravity.

Ryugu is a dark, spinning top-shaped asteroid that measures about 3,000 feet wide. The surface is covered in boulders. It's also incredibly dry.

Photos captured by the spacecraft have revealed an even distribution of dark and rough rocks, as well as those that are bright and smooth. Scientists believe there are two kinds of material on the asteroid because it likely formed from the leftover rubble after its parent body was hit.

The rocks are similar to carbonaceous chondrites, which are primitive meteorites. Some of the rocks contain small, colored materials called inclusions that could contain minerals like olivine. This is also found in carbonaceous chondrites.

Researchers from the Nature study also determined that the asteroid is largely made up of highly porous material. This could explain why carbon-rich meteorites are rarely found on Earth; our atmosphere protects against them and causes them to break apart into fragments.

Data was gathered for the study from the MASCOT lander during the mission, or Mobile Asteroid Surface SCOuT.

"Fragile, highly porous asteroids like Ryugu are probably the link in the evolution of cosmic dust into massive celestial bodies," said Matthias Grott, study author and expert at the German Aerospace Center's Institute of Planetary Research. "This closes a gap in our understanding of planetary formation, as we have hardly ever been able to detect such material in meteorites found on Earth."

The researchers believe it's possible that the highly porous structure of carbon-rich asteroids could be similar to planetesimals, or the material that eventually became planets in our solar system.

And asteroids, which act as leftovers from the beginning of the solar system, could shed light on early solar system processes like how planets formed. Unfortunately, that's not something for which astronomers have much direct evidence. They can only construct models based on what they know from studying the solar system and meteorites.

"Research on the subject is therefore primarily dependent on extraterrestrial matter, which reaches Earth from the depths of the Solar System in the form of meteorites," said Jörn Helbert, study co-author and research director from the German Aerospace Center's Institute of Planetary Research.

"In addition, we need missions such as Hayabusa2 to visit the minor bodies that formed during the early stages of the Solar System in order to confirm, supplement or -- with appropriate observations -- refute the models."

Hayabusa2 departed Ryugu in December 2019 and will return to Earth by the end of 2020. It's carrying precious cargo including the samples collected from two landing sites on the asteroid to be analyzed by scientists.

If it makes it back to Earth on schedule it will be the first mission to bring back samples from a C-class asteroid, which hasn't been visited before. C-class asteroids are the most common, comprising 75% of all known asteroids.

Photons captured by the immense gravity around the black hole form an intricate structure of light rings between the accretion disk and the event horizon boundary.

People were disappointed with the first direct image of a black hole, released last year. As if it were not enough to capture the image of an object that was considered impossible to see, 55 million light-years away, some were bothered because the image was blurred.

However, if the image had a better resolution, researchers estimate that we would see an impressive substructure around the event horizon: an infinite series of rings of light, gradually sharper, caused by extreme gravitational curvature.

“The image of a black hole actually contains a series of scrambled rings,” explains Michael Johnson, of the Harvard Smithsonian Center for Astrophysics. ” Each successive ring has about the same diameter but becomes increasingly sharper because its light orbited the black hole more times before reaching the observer. With the current EHT (Event Horizon Telescope) image, we’ve caught just a glimpse of the full complexity that should emerge in the image of any black hole.”

With their immense gravitational pull, black holes capture all photons that cross their event horizon, making their center dark – surrounded by the light generated by the hot gas that forms the accretion disk. The “photon rings” are inside the inner edge of the accretion disk, but outside the event horizon, and are formed by the light trapped in orbit by the strong gravity near the black hole.

Mathematical models suggest that the photon ring must create a complex substructure that consists of infinite rings of light – like the effect you see when you place one mirror in front of another. In the EHT image of the M87, we can see the accretion disk (the yellow and orange part) and the shadow of the black hole (the dark center). We cannot see the photon rings, as they are very thin and the resolution is not high enough.

But if we could see it, that photon ring would be the fingerprint of the black hole – its size and shape encode the black hole’s mass and rotation. With the images generated by the EHT, black hole researchers have a new tool to study these structures.

“Black hole physics has always had profound theoretical implications, but now it has also become an experimental science,” says Alex Lupsasca of the Harvard Society of Fellows. “As a theorist, I am pleased to finally collect real data on these objects that we have been thinking about abstractly for so long.”

Nearly 60 years ago, Nobel Prize-winning physicist Nicolaas Bloembergen predicted an exciting new phenomenon called nuclear electric resonance. But no one has been able to demonstrate it in action – until now.

Actual evidence of nuclear electric resonance has now been discovered by accident in a lab at the University of New South Wales (UNSW) in Australia, thanks to faulty equipment. The breakthrough gives scientists a new level of control over nuclei, and could seriously speed up the development of quantum computers.

Central to the phenomenon is the idea of controlling the spin of individual atoms using electrical rather than magnetic fields. That means more precise and more miniaturised management of nuclei, which could have profound impacts in a variety of fields.

"This discovery means that we now have a pathway to build quantum computers using single-atom spins without the need for any oscillating magnetic field for their operation," says quantum physicist Andrea Morello, from UNSW.

"Moreover, we can use these nuclei as exquisitely precise sensors of electric and magnetic fields, or to answer fundamental questions in quantum science."

In some situations, nuclear electric resonance has the potential to replace nuclear magnetic resonance, which is widely used today for a variety of purposes: for scanning human bodies, chemical elements, rock formations, and more.

The problem with the magnetic option is that it requires powerful currents, big coils, and a substantial amount of space – think about the size of an fMRI scanner at your local hospital, for example.

Not only that, in some ways it's a bit of a blunt instrument too. If you want to control individual atomic nuclei – for quantum computing, perhaps, or very small sensors – then nuclear magnetic resonance isn't a very good tool for the job.

"Performing magnetic resonance is like trying to move a particular ball on a billiard table by lifting and shaking the whole table," says Morello. "We'll move the intended ball, but we'll also move all the others."

"The breakthrough of electric resonance is like being handed an actual billiards stick to hit the ball exactly where you want it."

It was during a nuclear magnetic resonance experiment that the UNSW researchers cracked the puzzle set by Bloembergen in 1961, and it was all down to a broken antenna. After some head-scratching over unexpected results, the researchers realised their equipment was faulty – and demonstrating nuclear electric resonance.

With subsequent computer modelling, the team was able to show that the electrical fields could influence a nucleus at a fundamental level, distorting the atomic bonds around the nucleus and causing it to reorient itself.

Now that scientists know how nuclear electric resonance can work, they can research new ways to apply it. What's more, we can add this to the growing list of significant scientific discoveries that have been made by accident.

"This landmark result will open up a treasure trove of discoveries and applications," says Morello. "The system we created has enough complexity to study how the classical world we experience every day emerges from the quantum realm."

"Moreover, we can use its quantum complexity to build sensors of electromagnetic fields with vastly improved sensitivity. And all this, in a simple electronic device made in silicon, controlled with small voltages applied to a metal electrode."