For 10 years, central Chile has been gripped by unrelenting drought. With 30% less rainfall than normal, verdant landscapes have withered, reservoirs are low, and more than 100,000 farm animals have died. The dry spell has lasted so long that researchers are calling it a "megadrought," rivaling dry stretches centuries ago. It's not so different from the decadelong drought that California, some 8000 kilometers away, endured until this year.

By analyzing tree ring records, scientists have now found evidence that such tandem droughts are more than a coincidence: They are surprisingly common over the past 1200 years, and they may often share a common cause — an abnormally cool state of the eastern Pacific Ocean known as La Niña. "We did not expect there to be as much coherence as we see," says Nathan Steiger, a paleoclimatologist at Columbia University who presented the work this month at a meeting of the American Geophysical Union. "They just happen together." The results suggest that, in the future, extreme aridity could strike all along the Americas' western coast.

This year's fossil finds, from vast new collections of species to wonderful and weird curiosities, helped reveal the richness and diversity of life on Earth over the last half a billion years.

1. Impressive invertebrates

518 million years ago

China's Qingjiang biota is a treasure trove of beautifully preserved fossils, including jellyfish (left), comb jellies (middle), mud dragons (right) and arthropods. The remains document the Cambrian explosion, a rapid flourishing of life-forms, and include many organisms never seen before — even at the most famous Cambrian fossil site, Canada's Burgess Shale (SN: 4/27/19, p. 14).

So even more fossils just popped into existence, just like that. No wonder even Darwin had doubts.

2. Tetrapod walking

On a hillside above Stanford University, the SLAC National Accelerator Laboratory operates a scientific instrument nearly 2 miles long. In this giant accelerator, a stream of electrons flows through a vacuum pipe, as bursts of microwave radiation nudge the particles ever-faster forward until their velocity approaches the speed of light, creating a powerful beam that scientists from around the world use to probe the atomic and molecular structures of inorganic and biological materials.

Now, for the first time, scientists at Stanford and SLAC have created a silicon chip that can accelerate electrons - albeit at a fraction of the velocity of that massive instrument - using an infrared laser to deliver, in less than a hair's width, the sort of energy boost that takes microwaves many feet.

Writing in the Jan. 3 issue of Science, a team led by electrical engineer Jelena Vuckovic explained how they carved a nanoscale channel out of silicon, sealed it in a vacuum and sent electrons through this cavity while pulses of infrared light - to which silicon is as transparent as glass is to visible light - were transmitted by the channel walls to speed the electrons along.

The accelerator-on-a-chip demonstrated in Science is just a prototype, but Vuckovic said its design and fabrication techniques can be scaled up to deliver particle beams accelerated enough to perform cutting-edge experiments in chemistry, materials science and biological discovery that don't require the power of a massive accelerator.

"The largest accelerators are like powerful telescopes. There are only a few in the world and scientists must come to places like SLAC to use them," Vuckovic said. "We want to miniaturize accelerator technology in a way that makes it a more accessible research tool."

Team members liken their approach to the way that computing evolved from the mainframe to the smaller but still useful PC. Accelerator-on-a-chip technology could also lead to new cancer radiation therapies, said physicist Robert Byer, a co-author of the Science paper. Again, it's a matter of size. Today, medical X-ray machines fill a room and deliver a beam of radiation that's tough to focus on tumors, requiring patients to wear lead shields to minimize collateral damage.

"In this paper we begin to show how it might be possible to deliver electron beam radiation directly to a tumor, leaving healthy tissue unaffected," said Byer, who leads the Accelerator on a Chip International Program, or ACHIP, a broader effort of which this current research is a part.

Three researchers from the University of Oxford and the South Iceland Nature Research Centre have found evidence of tool use by puffins — the first evidence of tool use by any seabird. In their paper published in Proceedings of the National Academy of Sciences, Annette Fayet, Erpur Snær Hansen and Dora Biro describe their evidence of puffins using sticks to scratch a part of their body.

Over the past several decades, researchers have found many examples of non-human primates using tools — several types of passerine birds have been found to use tools, as well. Crows have been observed using sticks for many purposes, and parrots have been seen breaking seashells with rocks. But until now, no instances of tool use by seabirds have been observed. Because of their relatively small brains, many in the field believed they simply did not have the capacity to make use of a tool. But the researchers in this new effort have disproven these beliefs.

According to the most popular theory, proposed by Dutch astronomer Jan Oort, during a very early phase of the solar system's formation, the giant planets scattered objects into the outer regions far away from the sun. There, the icy rocks and dust particles formed a kind of cloud.

Passing stars may then scatter these objects back into the inner solar system, where we observe them as comets. Coming from the Oort cloud, these long-period comets often take many more than 200 years to orbit the sun.

"We present a second potential origin for such comets," says Tom Hands, a postdoctoral researcher at the Institute for Computational Science of the University of Zurich. "They can be captured out of interstellar space in the relatively recent past."

Two interstellar visitors made headlines in the past years. In 2017, scientists detected an asteroid-like body later named Oumuamua. In August 2019, amateur astronomer Gennady Borisov discovered a comet that came from interstellar space and will leave the solar system again. Oumuamua and Comet Borisov are both leftovers of planet formation in other solar systems, in the same way our comets and asteroids are thought to be the leftovers of planet formation in our solar system.


In the wake of the discovery of the first two interstellar objects, Hands and Walter Dehnen of the University of Munich used computer simulations to study how interstellar objects could be captured by our solar system.

"These stowaways form around distant stars before being flung towards us, making a journey of many lightyears before encountering Jupiter and being captured into the solar system," explains Hands. "We simulated 400 million such bodies as they approached the sun and Jupiter."

Sometimes you just have to stand back in awe at the beauty of the Universe - and that's absolutely the case with this image from the National Radio Astronomy Observatory (NRAO), which captures the side view of a spiral galaxy know as the Whale Galaxy.

But if you look closer, the stunning picture also shows something else: the magnetic 'ropes' around the edges of the galaxy's disc.

These filaments, like cosmic strands of hair, show the galaxy's magnetic field extending into its halo.

The green colouring shows filaments with their magnetic field pointing towards the viewer, with the blue colouring showing filaments with their magnetic field pointing away. This phenomenon has never before been directly observed in the halo of a galaxy.

"This is the first time that we have clearly detected what astronomers call large-scale, coherent, magnetic fields far in the halo of a spiral galaxy, with the field lines aligned in the same direction over distances of a thousand light-years," says astrophysicist Marita Krause, from the Max-Planck Institute for Radio Astronomy in Germany.

NASA's Center for Near-Earth Object Studies (CNEOS) is currently monitoring a miniature swarm of four asteroids currently heading towards Earth, two of which were only detected on January 1.

CNEOS is tasked with watching the skies for any potentially hazardous asteroids, but given the vastness of space, that's a lot of sky to check which may explain why two of the four asteroids were only spotted yesterday.

2020 AC, with a diameter of roughly 89 feet and traveling at approximately 13,000 miles per hour, will lead the charge, flying past the Earth at 1:56 am EST.

Welcome to the second day of the New Year! Like tasty sliders, these short news stories should get the juices flowing for big developments in 2020.

Electric Proteins

Dr. Stuart Lindsey at Arizona State University is an expert in single-molecule dynamics in biomolecules. Older methods of observing protein structure, such as X-ray crystallography, only gave single snapshots of the highly dynamic world, he says, where proteins rapidly change conformations and interact in complex ways. Electron transport has been well known in the cases of photosynthesis and metabolism. But a few years ago, his team was astonished to find that a run-of-the-mill protein conducted electricity. The protein was acting like a wire!

Further observations revealed that all proteins conduct electricity — even the ones that had "weren't designed to do this" —

The Pentagon is combing the AI developer community to try to build a self-starting swarm of AI-enabled drones capable of recognizing and tracking a target - ostensibly for search and rescue, but potentially for search and destroy.

The Joint Artificial Intelligence Center (JAIC) issued a request (RFI) late in December seeking the latest and greatest in AI and drone swarm tech - and looking for clever ideas on how to combine the two. The resulting smart-swarm, the agency said, should be self-directing, able to find and track humans ("and manmade objects," the RFI specifies) on its own, capable of streaming video of its activities, and willing to nudge its minders (who won't be minding it most of the time, since it's primarily AI-powered) when it has latched on to something interesting. The swarm will have to be able to move at least 50 knots (93 km/h), stay in the air for at least 2 hours, and cover 100 square nautical miles (343 square km).

The official purpose of the "smart swarm" is search and rescue, the RFI explains, while the JAIC program comprises four "mission initiatives" - "predictive maintenance, humanitarian aid and disaster relief, and cyberspace and robotic process automation."

So, where is number four? The RFI isn't telling, but we can speculate based on what JAIC is known to do. The AI-specialist department, which only debuted in 2018, ended up running Project Maven, the initiative to weaponize machine-learning and Big Data that was supposedly rejected by Google after employees got cold feet about helping the Pentagon kill people.

Schizophrenia is one of those disorders we still don't know the cause of, but it's likely to involve a complex mix of genes and environmental factors a person is exposed to in their childhood. According to new research, one such factor might have something to do with having pets.

A new study has found a relationship between dog ownership in our early years and a reduced likelihood of developing the neurological condition. Just how the two are linked isn't clear, but in context of research implicating a dysfunctional immune system, this tantalising conclusion demands a closer look.

"Serious psychiatric disorders have been associated with alterations in the immune system linked to environmental exposures in early life, says pediatrist Robert Yolken from Johns Hopkins Children's Centre, Maryland.

"Since household pets are often among the first things with which children have close contact, it was logical for us to explore the possibilities of a connection between the two."

Having a pet roam around the family home when a child is still crawling around through the dust and dander has long been considered a good way to build a healthy immunity.