Author: ANotiCiasabi

After an evening of trick-or-treating in Maplewood, Minnesota, on October 31, 2003, 4-year-old Vincent Ledvina and his family were heading home for the night. Suddenly, he noticed the sky was lit up in ethereal colors that were like nothing he had ever seen before. To Ledvina, as a child, it looked like flames rippling across the sky. When he got to his house, he watched the lights from a west-facing window.

“I was kind of fascinated but also just kind of mystified. I had no idea what was going on,” he says. He stared outside, taking in the glow, until his parents made him go to bed. “I was just totally transfixed by it.”

The next day, Ledvina learned he’d seen a rare geomagnetic storm, now known as the Great Halloween Solar Storm of 2003, that brought the northern lights much farther south than usual. That experience launched an interest in the night sky, which morphed into an obsession with the northern lights.

Now, Ledvina studies space physics in a doctoral program at the University of Alaska, Fairbanks. He’s hooked on chasing auroras, going out to look on every clear night that he can.

“The addiction is real,” says Tom Kerss, an astronomer and professional aurora chaser based in the United Kingdom and United States. He’s seen auroras more than 300 times—he’s gazed upon their light during the peak of the Geminid meteor shower, taught travelers on Norway’s Hurtigruten cruise lines as the company’s chief aurora scientist and even accidentally plunged his foot through the ice on a frozen stream while staring upward in Iceland.

“There aren’t many of us in the world who call ourselves ‘professional aurora chasers,’ but what we would do is we would try to share that experience with other people,” Kerss says.

On May 10 and 11, people around the globe got the unusual experience of seeing the northern lights—many for the first time—from their own hometowns. Intense solar activity set off a geomagnetic storm in Earth’s atmosphere that hit level G5—the strongest one since the night in 2003 that captivated Ledvina as a child.

This time, as auroras became visible from a mind-boggling portion of the planet, seasoned aurora chasers went outside accompanied by first-time viewers. And for many, being able to share the expertise they’ve gained from each northern lights sighting was rewarding.

“It was surreal, and it was great to experience it with people who haven’t seen the aurora before,” says Prisco Blanco, a Pasco, Washington, resident who chases auroras when they appear over the state. “To view how friends and family were able to see and experience it for the first time when they haven’t, for me that was the people aspect of it. It felt worth it.”

Leading up to May 10, Blanco was just coming off a two-week period of intense work, “nonstop” between his job at Columbia Basin College and hosting shows in Spanish at a local planetarium. He was looking forward to a free weekend to sleep in. But then he heard the sun had launched a vast amount of material toward Earth. “I was like, ‘I’m not going to bed at all,’” he says. “I did not sleep. … I’m still recovering.”

Kerss managed to see a faint glow from Florida, like a colorless veil that was giving off its own light. Witnessing the northern lights there was “unusual,” he says. “I just didn’t think it would ever be possible in my lifetime.”

Ledvina, for his part, had unwittingly planned a vacation during the time of the solar storm. Nevertheless, he spotted the northern lights—from Leh in Indian-administered territory.

“Every night’s different—that’s why I do it. The aurora’s never the same,” Ledvina says. “Every night you’re honing your skills, and your intuition gets a little bit sharper after every single aurora.”

For people who missed seeing May’s event—and for those hoping to catch another appearance of the ethereal skyward glow—we put some of the biggest northern lights questions to aurora chasers and scientists. Here’s everything you need to know about the phenomenon and how best to see it in the coming years.

What are auroras?

The dazzling lights in Earth’s atmosphere that we know as auroras are intricately tied to activity on the sun. Our nearest star often develops dark regions called sunspots, in which its magnetic field gets tangled up, making them cooler than the surrounding areas. But these spots are active, with the potential to erupt.

Sunspots can fling material outward in different ways: solar flares and coronal mass ejections (CMEs). A solar flare is a burst of radiation, while a CME expels plasma and magnetic fields. Both are impressive, but when it comes to seeing auroras, it’s the CMEs that count.

“If you’re thinking of a sunspot as a gun … the solar flare is basically a muzzle flash, and the coronal mass ejection is the bullet,” Blanco says. “The flash is pretty, it’s pretty cool to look at, but … we won’t get aurora, because it needs that material to make its way into our magnetosphere.”

When the ejected, charged particles reach Earth’s vicinity, our planet’s magnetic field siphons them toward the poles. Once there, the rapidly moving solar particles slam into atoms of gas in our atmosphere—mostly nitrogen and oxygen—giving them energy. As these atoms release the excess energy, they glow brightly in vivid color, creating what we know as the northern and southern lights.

An aurora’s hue depends on the altitude and type of gas being energized. Green auroras—caused by oxygen at lower altitudes of about 60 to 190 miles—are the most common and easiest to see. At higher altitudes, roughly 190 to 250 miles above ground, oxygen glows scarlet. Nitrogen can produce red or blue hues, and near the bottom of auroras, it might cause a pink band at a height of around 60 miles. Auroras can also appear purple.

In some rare cases, the northern lights can even produce sound—making crackling or snapping noises. Experiencing this phenomenon is “perhaps the white whale of all aurora chasers,” Kerss says. “To hear the aurora is not something I’ve ever managed to do.”

Why are we seeing more auroras this year?

Like the Earth, the sun has magnetic north and south poles—but unlike Earth, those poles flip positions every 11 years. This shift drives an 11-year solar cycle in which the star experiences a period of low magnetic activity and a period of high magnetic activity, which culminate, respectively, in a “solar minimum” and a “solar maximum.”

Right now, we are approaching a solar maximum, which means the sun has a nearly peak number of sunspots and heightened levels of solar flares, CMEs, solar wind and other releases of particles.

The last solar maximum occurred in 2014—but that one was “kind of wimpy,” says Elizabeth MacDonald, a heliophysicist at NASA’s Goddard Space Flight Center. It didn’t produce any storm that could compare to the one on May 10 or the Halloween storm of 2003, which was during the prior solar maximum.

Experts predict the upcoming solar maximum will occur in 2025—though some say it could arrive early, as soon as later this year. But the maximum isn’t necessarily one year; Ledvina thinks of it as a “high season” that could bring multiple years with more sunspots and solar activity.

When is the best time to watch auroras?

No matter where you are on the globe, the best time to spot auroras is going to be in the darkest hours—often, that’s just after midnight local time.

“Of course, the brightest part of the aurora may occur during the daytime where you are; it may occur later in the morning. But if you go out around that midnight hour, and if you’re out particularly between around 10 p.m. through to around 2 a.m., that’s going to be the best time to view,” Kerss says.

The time of year is also important—the typical aurora-chasing season is between September and March in the Arctic. Attending on either end of this window, right around the autumn and spring equinoxes, might be the ideal period. At this time, the sun is more active, and the alignment of Earth is most favorable to aurora viewing.

Another perk of watching around the equinoxes: If you’re traveling to the Arctic, you’ll likely have slightly milder weather and avoid the full chill of midwinter.

How can you make the most of a trip to see auroras?

The best aurora viewing is at high latitudes in the Arctic Circle (or, conversely, at very southern latitudes). Dress warmly, and be prepared to stay outside for a long time around midnight.

Crucially, book a long enough trip to give you several chances to see the auroras, in case cloudy weather blocks your view on some nights. “You have to go for at least three nights, ideally a week,” Ledvina says.

“You’ll be kicking yourself if you come home from a beautiful location having missed it, and then it kicks off the following night, and you read about it on the news,” adds Kerss.

To improve your visibility, you could align your trip with a new moon, when skies will be darker. And darkness is key—if you’re in the Arctic during the summer, daylight persists around the clock, making it impossible to see the northern lights.

If you can, experts recommend booking a tour with a guide. They’ll know the local area and they’ll know how to navigate the potentially icy or snowy roads. You can pick their brain for more aurora knowledge. And the guide won’t be fighting jet lag, so they’ll be better equipped to stay up late.

“At least for one night, I think it’s worth it,” Ledvina says. “It’s always good to hire a guide. It’s safer.”

What are some tips for viewing auroras in your local area?

Just as for any skywatching event, you’ll want to get as far away from light pollution as possible, and your view of auroras will be clearer on moonless nights.

Even during a large geomagnetic storm that brings the northern lights to the south, aurora chasers say you should manage your expectations. “It’s very different than what you see in pictures,” Blanco says. “Your camera can see a lot of things that the eye can’t see.”

The mid-latitude northern lights might be dimmer than expected, and they can be obscured by the car headlights of other aurora-spotting hopefuls. This means your naked-eye view might not match up to what you see on social media. But on the bright side, your phone camera is a great tool for finding the glow.

“You can basically use your phone to get a better sense of if the aurora is really there,” MacDonald says. “It’s kind of like a mini-night-vision tool that you have, because the cameras are much better than our eyes at picking up color.”

As a result, your phone camera can help you discern whether you’re truly seeing the northern lights or just noticing nearby light pollution. If it really is an aurora, that could be a cue to move to a darker spot for viewing.

Once you know an aurora is coming, plan ahead. CMEs take a couple of days to reach Earth after they’ve launched, so you will have some time to pick a few nearby dark-sky sites and follow local weather conditions to determine the best spot to view.

How can you keep up with when auroras will happen?

Sites like the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center and Space Weather Live—which also has an app—give forecasts for when CMEs from the sun might hit Earth and where the auroras may appear. Experts track these predictions and will start spreading the news on social media, so following aurora chasers and scientists could also bring you early alerts.

Aurora chasers monitor live sky cams to get a sense of the aurora activity. “I have the all-sky camera feed on one screen and my homework on the other, and I’m constantly checking,” Ledvina says.

Keeping tabs on the local weather is also key. Blanco suggests looking at webcams that show real-time weather conditions rather than relying on apps to estimate the cloud cover, for example.

Another way to keep up with sightings is through Aurorasaurus, a citizen science platform founded by MacDonald that tracks auroras through user-submitted photos and reports.

People who sign up for an Aurorasaurus account can opt into alerts of aurora activity. “There’s actually two different kinds of alerts. One of them is just if you are in the region where the aurora model, driven by space data, thinks that you should be able to see the aurora to the north,” MacDonald says. The other alert is more dynamic. “If citizen scientists are reporting aurora there, and you have signed up for an alert there, it’ll adapt” and send a notification.

Scientists still have a lot to learn about auroras, MacDonald says. But aurora chasers and the public can crowdsource valuable observations to contribute to researchers’ understanding. And this solar maximum offers the best opportunity to photograph the auroras yet.

“Most cellphones can take extraordinary pictures of aurora now, which they couldn’t 11 years ago,” MacDonald says. “And back in 2003, most people didn’t have digital cameras. So this latest storm is really the biggest storm since then and the first that has been imaged with digital cameras.”

Will we see more auroras like earlier in May?

The geomagnetic storm on May 10 came from a series of at least seven CMEs launched by a blob of sunspots the size of 17 Earths.

“Our first potential chance for [a repeat event] would be when the really complex sunspot that drove this storm rotates back around on the face of the sun,” which is a 27-day process, MacDonald says. That makes this week the next opportunity for such widespread sightings of auroras.

But this mass of sunspots appears to be decaying already, says Ledvina, lowering the chance of an equally powerful storm in early June.

As the year goes on, however, the sun will continue building to its maximum level of activity, raising the odds that it will hurl more ejections of charged particles our way. We can count on seeing some spectacular auroras, but another show that rivals the one last month would be a real stroke of luck.

“As much as I would love a repeat of what happened on May 10, those are exceedingly rare events,” Blanco says. “A lot had to go right for that to happen.”

For another massive geomagnetic storm to occur, the sun would not only have to launch an incredibly powerful CME (or multiple in a row), but its material would have to be pointed at Earth. And “the Earth is a small target,” Kerss notes.

Still, the recent, widespread display of auroras is raising hopes of particularly strong solar activity in the coming months and years. Historically, some of the biggest geomagnetic storms—like the one on Halloween in 2003—have occurred just after the maximum passed.

“I think that’s where a lot of the hype is coming from,” Blanco says. “If we got a big one this early on, what happens once we get to late 2025, 2026?”

Se os grandes símios são conhecidos por algo, é por serem grandes em tamanho. Um grande gorila pode pesar quase 500 libras, por exemplo, e o extinto grande símio Gigantopithecus era provavelmente uns cem quilos mais pesado, o maior primata de todos os tempos. Mas agora os paleontólogos identificaram o que pode ser o menor dos grandes símios, um primata que vivia nas florestas da Alemanha pré-histórica e era do tamanho de um cachorro pequeno.

Cientistas descobriram fósseis de dois dentes e uma rótula que, segundo eles, representam um novo primata, chamado Burônio Manfredschmid. Por mais insignificante que isso possa parecer, os dentes de mamíferos fossilizados são frequentemente muito distintos e permitem que os pesquisadores separem as espécies umas das outras. Neste caso, a paleoantropóloga Madelaine Böhme e colegas da Universidade de Tübingen propõem, Burônio era uma espécie até então desconhecida de hominídeo, ou grande macaco, que viveu em florestas quentes há cerca de 11,6 milhões de anos. Os pesquisadores descreveram os fósseis na sexta-feira em PLOS Um.

Os primeiros fósseis do antigo macaco foram descobertos há mais de uma década. Em 2011, Böhme relembra, os pesquisadores começaram a procurar fósseis em um sítio chamado Hammerschmiede, no sul da Alemanha. “Logo no primeiro ano”, ela diz, “descobrimos o molar superior e a rótula de Burônio bem um ao lado do outro.”

Böhme e coautores estavam confiantes de que as descobertas iniciais eram de um primata, mas não sabiam imediatamente de que tipo. “Devido ao seu pequeno tamanho, inicialmente pensamos que eram pliopithecus”, diz Böhme. Os pliopithecus eram macacos pré-históricos que se espalharam pela Eurásia durante o Mioceno, entre 5,3 milhões e 23 milhões de anos atrás, e alguns eram bem pequenos. O primeiro dente e o pequeno osso poderiam ter vindo de tal primata, mas muito pouco havia sido descoberto para que os pesquisadores tivessem certeza. Os fósseis esperaram por descobertas adicionais para colocá-los em contexto.

A identidade de Burônio não entrou em foco até que os pesquisadores encontraram os fósseis de outro macaco no mesmo local. Em 2015, Böhme e colegas encontraram os fósseis de um hominídeo que os pesquisadores eventualmente nomeariam Danúvio sorriu. Com base nos fósseis disponíveis, os pesquisadores estimaram que Danúbio podia chegar a pesar cerca de 30 quilos e era um animal muito maior do que a criatura representada pelo dente e pela rótula.

Estudando os dentes de Danúbio levou os pesquisadores a reavaliar as descobertas de 2011, e um segundo dente misterioso também foi encontrado em 2017. Os fósseis representavam um macaco adicional, Burônioque teria pesado cerca de 22 libras em vida. “Agora publicado, Burônio é o menor hominídeo conhecido”, diz Böhme.

Mas outros pesquisadores não têm certeza absoluta de que Burônio e Danúbio são espécies diferentes. A rótula fossilizada é pequena, mas pode ter vindo de um jovem ou de um sexo diferente de Danúbiodiz a paleoantropóloga Kelsey Pugh, do Brooklyn College, que não estava envolvida no novo estudo. Tanto os macacos modernos quanto os extintos podem variar muito em tamanho entre os sexos, ela diz, e então o pequeno tamanho da rótula não é suficiente para dizer a qual espécie de primata ela pertence.

Com a rótula levantando questões, os detalhes dentários são o que distingue principalmente os macacos maiores e menores. O novo estudo diz que a diferença de tamanho entre os Burônio e Danúbio molares são maiores do que em qualquer espécie dentro do grupo mais amplo de primatas ao qual os macacos pertencem. A disparidade significativa de tamanho acrescenta algum suporte ao caso de que o molar encontrado em 2011 e o Danúbio fósseis representam espécies diferentes.

Além da diferença de tamanho entre os molares, os detalhes internos também distinguem o dente novo daquele anterior. Danúbio. O esmalte do Burônio molar é muito mais fino do que o de um comparável Danúbio molar, sugerindo que o macaco menor estava se alimentando de alimentos mais macios, como folhas, do que seu parente maior. “Embora a espessura do esmalte seja bastante variável em hominoides vivos, os dois Danúbio os molares são bastante distintos nessa característica, indicando razoavelmente uma diferença na dieta”, diz Pugh.

A diferença alimentar sugere que tipo de vegetação crescia no habitat do Mioceno onde os macacos viviam. De volta quando Burônio e Danúbio estavam vivos, o que é hoje a Baviera era uma paisagem plana e pantanosa no sopé dos antigos Alpes. A área imediata em que os fósseis foram preservados abrigava um riacho sinuoso, diz Böhme, cercado por plantas arbustivas que cresciam densamente ao longo das margens. E embora o clima global fosse mais quente do que hoje, a área estava longe o suficiente para o norte para que houvesse mudanças ao longo das estações, as folhas frescas da primavera e do verão se tornando mais raras à medida que os dias curtos de outono e inverno se instalavam. A maneira como os macacos forrageavam deve ter mudado conforme as estações afetavam o crescimento das plantas locais.

Selecionar alimentos diferentes teria permitido que os macacos de Hammerschmiede coexistissem. “Há muitos exemplos de ecossistemas modernos onde um grande número de espécies de primatas conseguem coexistir”, diz a paleontóloga Mary Silcox, da Universidade de Toronto Scarborough, que não estava envolvida no novo estudo. A floresta Kibale de Uganda, ela observa, é o lar de 14 espécies de primatas sobrepostas, variando de bebês do mato a macacos e macacos como chimpanzés. “Os primatas são muito bons em dividir o espaço de nicho”, ela diz, e o registro fóssil indica que macacos, macacos e seus parentes têm encontrado maneiras de coexistir nas mesmas florestas por dezenas de milhões de anos.

Parte do que permite que várias espécies de macacos e símios coexistam hoje é que muitos vivem em florestas equatoriais quentes, onde há comida disponível o ano todo. A situação em Hammerschmiede é diferente, mostrando a engenhosidade dos símios encontrados lá. A vegetação onde Burônio e Danúbio viveu tinha árvores decíduas e mudou ao longo do ano. “Isso fala da produtividade dos paleoecossistemas de Hammerschmiede que eles permitiram que dois grandes macacos coexistissem apesar da escassez sazonal de alimentos”, diz Böhme.

Os detalhes dessa coexistência aguardam mais fósseis que permitirão aos paleontólogos obter uma visão melhor de como eram os macacos de Hammerschmiede em vida. Mais peças esqueléticas ajudarão a resolver as relações dos macacos do sítio, também, o que por sua vez ajudará os paleoprimatólogos a entender como os macacos pré-históricos viviam em um lugar bem diferente dos habitats dos macacos não humanos de hoje. Apesar das diferenças na interpretação, Pugh diz, “é preciso muito trabalho para descobrir novos fósseis, e esses autores fizeram um trabalho incrível descobrindo novos fósseis de macacos em Hammerschmiede”. Com sorte, ainda mais fósseis em breve trarão esses nossos antigos parentes para uma visão mais clara.