This year has produced an unprecedented news frenzy. As the deadly coronavirus pandemic raged around the world, lives were uprooted. Readers eagerly anticipated every bit of progress toward a vaccine. The killing of George Floyd sparked nationwide protests against police brutality and systemic racism. Wildfires rampaged across western North America, including five of the six largest fires in California since 1932, and hurricanes tore through coastal cities, with so many forming that scientists ran out of names for the storms. In the final few months of 2020, a historically divisive election dominated headlines.
Yet among these pivotal events were an array of scientific discoveries that slipped under the radar. As 2020 comes to a close, we look back at ten significant developments that you might have missed.
Bursts of dust from aging stars, similar to the Egg Nebula pictured above, are one possible source of the large ancient grains found in meteorites.
Image by NASA, W. Sparks (STScI) and R. Sahai (JPL)Oldest material found on Earth is more ancient than our solar system
Billions of years before our sun winked into existence, a dying star flung dust out into space. Now a bit of that stardust, trapped in a meteorite that collided with Earth, was dated as the oldest material yet found on our planet. The dust coalesced with other rocks inside what would become the Murchison meteorite, which lit up skies over Australia in September 1969 as it careened to the surface of our planet.
A fresh analysis of these ancient rocks found grains of stardust that are between 4.6 billion years and roughly 7 billion years old. Scientists estimate that these early dust pieces lurk only in about five percent of meteorites, but that hasn’t discouraged them from continuing to hunt for these clues to our galaxy’s history.
An illustration shows what Tyrannosaurus rex hatchlings may have looked like. The newly described embryonic fossils were not from T. rex, but an earlier species of related tyrannosaur that has not been identified.
Illustration by Julius CsotonyiFirst tyrannosaur embryos discovered
Researchers have identified the remains of tyrannosaurs so young they hadn’t yet broken free from their shells. The discovery comes from finds at two different sites—a foot claw unearthed in 2018 from the Horseshoe Canyon Formation in Alberta, Canada, and a lower jaw recovered in 1983 from the Two Medicine Formation of Montana. Analysis of the remains, which are 71 to 75 million years old, revealed that tyrannosaurs started out surprisingly small, measuring an estimated three feet long—about the size of a Chihuahua, but with an extra-long tail. This length is only about a tenth of their full-grown counterparts and might help explain why researchers haven’t yet found other examples of these tiny tyrants—most scientists just weren’t looking for such a pint-sized predator.
An artist’s impression of the InSight lander on Mars. Short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, InSight is designed to listen for tectonic activity and meteorite impacts, study how much heat is still flowing through the planet, and track Mars’s wobble as it orbits the sun.
Illustration by NASA/JPL-CaltechMars is humming, and scientists aren’t sure why
In November 2018, a spacecraft arrived on Mars’s frigid, dusty surface to take the planet’s pulse. Known as the InSight lander, the robotic geologist recently beamed some of its early findings back to Earth, exciting and perplexing scientists around the world. Among these curiosities is a Martian hum—a quiet, constant drone that seems to pulse to the beat of “marsquakes” that rattle the planet.
The hum’s origin remains unknown. Earth has many such background vibrations, from the roar of winds to the crashing of waves against the shore. But the music of Mars reverberates at a higher pitch than most natural hums on Earth. Perhaps the geology underneath the lander amplifies one particular tone, or the lander itself might even be generating the noise. “It’s extremely puzzling,” Bruce Banerdt, the principal investigator of the InSight mission, told National Geographic in February.
Mystery of the star Betelgeuse’s strange behavior finally solved
Betelgeuse is usually among the brightest stars in the sky, but in December 2019, its intense twinkle mysteriously dimmed. The dramatic change set scientists abuzz: Perhaps Betelgeuse was at the end of its life and could explode in a supernova brighter than the full moon. Yet in August of this year, NASA announced a far less extraordinary explanation for its suddenly shadowed face: The star burped.
Observations by the Hubble Space Telescope revealed that the star likely sent out a superhot jet of plasma that cooled as it whipped outward. The process formed a cloud of stardust that could have blocked Betelgeuse’s light from eager earthbound viewers. The star returned to its normal brightness this past spring—so sky-watchers will have to wait for its fiery death.
Some 110 million years ago in what's now northwestern Alberta, the nodosaur Borealopelta markmitchelli ate ferns in a recently burnt landscape—a detailed vignette provided by a new study of its stomach contents.
Illustration by Julius CsotonyiStunning details of an armored dinosaur’s last meal
The brilliantly preserved front half of a 110-million-year-old armored dinosaur—bony plates, scales, and all—surprised and delighted scientists after it was accidentally unearthed in 2011 by a heavy equipment operator working in an Alberta oil sands mine. But this year, the spiky creature served up even more excitement when an analysis revealed that the animal’s last meal was also preserved in its belly.
The dinosaur was a nodosaur, which is a type of ankylosaur but lacks the clubbed tail of some of its cousins. The ball of fossilized vegetation from the nodosaur’s stomach revealed that a few hours before its death, it largely munched on a specific type of fern selected from a variety of available plantlife. Rings of woody twigs eaten along with the ferns revealed that the nodosaur likely died during the summer. While only a single meal, the find provides an exceptional look at the final hours of a creature's life more than a hundred million years ago.
A health worker carries Kakule Kavendivwa, 14, to a waiting ambulance in Beni last year. The day before, Kakule's sisters had taken him to a nearby health center, but fled when the team encouraged them to go to a treatment center. The health center alerted the World Health Organization, which found the family. After several hours of talking with community outreach workers, they allowed an ambulance to take him for treatment.
Photograph by Nichole SobeckiThe second-largest Ebola outbreak is finally over
On June 25, the World Health Organization declared the end of the second largest Ebola outbreak, which infected more than 3,480 and killed nearly 2,300. Known as the Kivu outbreak, the event began in August 2018 with a cluster of cases near Kivu, in eastern Democratic Republic of the Congo. Ebola is a hemorrhagic fever marked by a host of symptoms—including bleeding, fever, stomach pains, weakness, and rashes—and is spread through direct contact with an infected person or animal’s blood or bodily fluids. Containing the disease in Kivu was particularly difficult due to local unrest, which led to suspicions about any government or international organization efforts to curb the disease’s spread. However, armed with a new vaccine, healthcare workers, led by Michael Yao of the WHO, launched a campaign to vaccinate anyone who may have been exposed. By also improving community engagement, this effort led to the vaccination of more than 300,000 people.
“We should celebrate this moment, but we must resist complacency,” WHO Director-General Tedros Adhanom Ghebreyesus said in a press release about the end of the outbreak. “Viruses do not take breaks.” Another outbreak (now contained) occurred in early June near the DRC’s Équateur Province.
Skull fragments from an early Homo erectus individual were discovered in South Africa—the first time the species was found in the region.
Reprinted with permission from Herries et al., Science 368:47 (2020).Found: Oldest Homo erectus skull
Extracted from rocks northwest of Johannesburg, South Africa, the skull pieces initially seemed like they came from an ancient baboon. But as Jesse Martin and Angeline Leece, both students of La Trobe University in Australia, assembled the pieces, they realized they held the first braincase of Homo erectus yet found in Southern Africa. What’s more, dated to some two million years old, the skull marks the earliest remains of this ancient human ancestor. “I don’t think our supervisors believed us until they came over to have a look,” Martin told National Geographic last spring. The discovery helps researchers continue to decipher our tangled family tree, figuring out when and where our host of ancient relatives arose.
Reconstruction of the nesting ground of Hypacrosaurus stebingeri from the Two Medicine formation of Montana. In the center a deceased Hypacrosaurus nestling has the back of its skull embedded in shallow waters. A mourning adult is portrayed on the right.
Illustration by Michael RothmanHints of the first dinosaur DNA
In Jurassic Park, isolating dinosaur DNA is as simple as extracting the blood feast of an ancient mosquito encased in amber. While we’re still far from bringing this piece of science fiction to life, researchers did make a mighty leap forward in the study of fossilized DNA. While studying well-preserved fossils more than 70 million years old, a team identified the outlines of cells, forms that may be chromosomes, and several possible nuclei—the structures that house DNA. They haven’t extracted DNA from the fossil cells, however, so they can’t confirm yet whether the material is unaltered DNA or another genetic byproduct. But it’s an exciting look at the finer details that fossilization can preserve. “The possibilities are absolutely thrilling,” David Evans, a paleontologist at the Royal Ontario Museum who wasn’t involved with the study, told National Geographic in March.
Scientists compare notes on the stratigraphy of Chiquihuite Cave in preparation for sampling traces of plant and animal DNA from the sediments.
Photograph by Devlin GandySurprise cave discoveries may push back people’s arrival in the Americas
Stone objects recovered from deep inside the Chiquihuite Cave in Mexico hint that humans may have arrived in the Americas as early as 30,000 years ago—roughly twice the age of most current arrival estimates. This date is hotly debated among archaeologists, with many initially placing the first human presence in the Americas at around 13,500 years ago, as ice sheets receded and migration routes from Asia opened up. But recent evidence has pushed the date of human arrival back by thousands of years. And the new analysis of stone artifacts, including blades, projectile points, and rock flakes, interspersed with bits of charcoal dated to some 30,000 years old, suggests humans likely arrived in the Americas before glaciers began to melt.
Studying the cave suggests it could have been hospitable tens of thousands of years ago, as the region was likely much cooler, wetter, and greener than it is today. Yet no human remains have yet been found, and the new study is stirring controversy among scientists. "Chiquihuite's main contribution is that it brings you another tiny light, another tiny signal, that there is something there," the paper’s lead author Ciprian Ardelean, an archaeologist with the Autonomous University of Zacatecas, told National Geographic in July.
Newly discovered tower of coral, standing more than 1,640 feet tall, adds to the seven other so-called detached reefs in the northern Great Barrier Reef.
Schmidt Ocean InstituteA reef taller than the Empire State Building
A team of Australian scientists on board the Schmidt Ocean Institute’s research vessel Falkor was mapping the northern Great Barrier Reef seafloor when they stumbled on a towering skyscraper of coral more than 1,640 feet tall—the first of its kind discovered in more than 120 years. Known as a detached reef, the newfound coral tower is one of eight now known in the region. These natural structures provide vital habitats for creatures like turtles and sharks, which flit in and out of the deep waters adjacent to the Great Barrier Reef. The team mapped the detached reef, finding a variety of lifeforms thriving in the ecosystem. They collected samples of rock, sediments, and some organisms that will be sent to labs for analysis.
While more details about this reef will likely emerge, taxonomists studying the imagery and video have already identified several new fish species. Wendy Schmidt, co-founder of the Schmidt Ocean Institute, said in a press release that the discovery is part of a revolution in marine science: "Thanks to new technologies that work as our eyes, ears, and hands in the deep ocean, we have the capacity to explore like never before.”
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