• The Palisades and Eaton fires have razed thousands of homes and burned tens of thousands of acres.
• Some buildings have survived, though, like the Getty Villa art museum in Pacific Palisades.
• The Villa is not your average home, but homeowners can learn from what Getty staff have been doing all year.

As the Palisades and Eaton fires burned through thousands of acres on Tuesday, razing nearly 2,000 homes, the iconic Getty Villa remained standing with minor damage. Meanwhile, homes and trees around it went up in flames.

"We deeply appreciate the tireless work and dedication of the Los Angeles Fire Department, Los Angeles County Fire Department, and other agencies," the museum said in a statement Wednesday morning.

The Getty Villa is part of the J. Paul Getty Trust, which includes the largest endowment of any museum in the world, estimated at more than $8 billion in 2023. It houses the trust's collection of Ancient Greek and Roman art.

Fire departments used "state-of-the-art air handling systems" to help protect the building, Katherine E. Fleming, the president and CEO of the Getty Trust, told USA Today.

Moreover, builders designed the galleries with double-walled construction, which also helped protect the precious art inside.

However, it wasn't just expensive architecture and state-of-the-art firefighting that helped. Getty staff have been consistently clearing brush from the surrounding area all year as part of its fire-mitigation efforts, the museum said.

That's a crucial lesson for homeowners in fire-risk areas.

Yard work to save your home

The Palisades fire has become the most destructive ever to hit Los Angeles, CNN reported, citing CalFire data.

The fire has been fueled by an explosion of grasses and brush that grew abundant over the past two winters, which were rainier than usual. But with drought conditions over the past few months, that brush dried out, becoming kindling for the fast-moving blazes.

To mitigate the risk of fire, cities, fire departments, and community members can clear dried grasslands around residential areas.

Individual homeowners can also protect their properties by clearing a 5-foot perimeter around their houses and removing flammable materials like ornamental plants, bark mulch, or deck furniture.

"This is an urban fire. We're burning urban fuels," said Pat Durland, a wildfire-mitigation specialist and instructor for the National Fire Protection Association with 30 years of federal wildfire management experience.

Keeping gutters and roofs clear can also prevent spot ignitions that can send entire structures up in flames.

"People believe that they're helpless," Durland told Business Insider in 2023. But that's not the case, he said. "Nine out of 10 times, this boils down to two words: yard work."

Homeowners can also install noncombustible, 1/8-inch mesh screening on any vents to a crawl space or attic to prevent embers from entering the home that way.

"You are where the rubber meets the road. The things you do on your house and around your house are going to make the difference," Durland said.

• NASA scrapped its $11 billion plan to return samples from Mars to Earth by 2040.
• It now has not one but two new options to choose from — both are faster and cheaper.
• The samples could return as soon as 2035 and may contain the first-ever signs of ancient alien life.

The Perseverance rover is building up a stash of rocks on Mars that could contain the first-ever signs of alien life, but NASA is scrambling to figure out how it will bring them back to Earth for analysis.

NASA had a plan but it got "out of control," in the words of the agency's administrator, Bill Nelson. After a series of delays, the cost ballooned to $11 billion and the samples wouldn't be landing on Earth until 2040.

So Nelson scrapped that plan in April and called for new proposals from outside and within NASA.

After months of assessment, on Tuesday, Nelson announced that "the wizards at NASA" had come up with a new plan, which could bring the Mars rocks to Earth as early as 2035 for as cheap as $5.8 billion.

"We want to have the quickest, cheapest way to get these 30 samples back," Nelson said during a NASA presser on Tuesday.

For that to work, he said the incoming Trump administration will need to get on board.

"This is going to be a function of the new administration in order to fund this," Nelson said. "And it's an appropriation that has to start right now, fiscal year '25."

The search for alien life on Mars

NASA is not looking for active alien life but rather fossilized hints of long-gone microbial life.

The $2.4 billion Perseverance rover has spent the last four years exploring Jezero Crater, which was a lake billions of years ago. If microbes ever lived on Mars, this is the ideal spot to search for evidence of them.

In fact, in July, Perseverance stumbled on a rock in Jezero Crater that contained some of the strongest potential evidence of ancient alien life to date.

One of the rock's outstanding features was tiny white "leopard spots" that could suggest the presence of chemical reactions similar to those associated with microbial life on Earth.

It's still uncertain whether this is truly a sign of alien microbes. There could be non-biological explanations for the spots. To check, NASA needs to get that rock here to Earth for study in laboratories.

NASA's new plan

Bringing Perseverance's Mars samples to Earth will be complicated.

NASA must launch a mission that collects the samples from the Martian surface and launches them into Mars' orbit, where they must meet up with a European spacecraft designed to grab them and carry them back to Earth.

To make things simpler and reduce costs, NASA focused on how it would drop that mission to the Martian surface.

In order to maximize the chance of the sample return mission moving forward, NASA chose not one but two options to pursue.

The first option would involve using existing technology that's previously landed on Mars. That's a sky crane, similar to the ones that helped lower NASA's Curiosity and Perseverance rovers on Mars' surface.

The second option involves working with existing commercial partners, like SpaceX and Blue Origin. In that scenario, NASA would use new commercial technology, untested on Mars, like a heavy lander, Nelson said.

Both paths would cost around $6 or $7 billion and deliver the samples to Earth before 2040, NASA determined.

Nelson said he expects NASA to choose one of those paths forward in 2026 since the engineering work required to fully understand each option will take about a year.

He added that NASA will need $300 million to do that work in fiscal year 2025. Trump would have to include that expense in his budget proposal, and Congress would have to approve it.

"And if they want to get this thing back on a direct return earlier, they're going to have to put more money into it, even more than $300 million in fiscal year 25. And that would be the case every year going forward," Nelson said.

As part of the transition to the new Trump administration, Nelson will likely be handing the agency over to Trump-nominee Jared Isaacman, a billionaire and two-time SpaceX astronaut.

After Trump nominated him for NASA Administrator, Isaacman wrote in a post on X that "Americans will walk on the Moon and Mars."

His position on the Mars Sample Return mission is unclear. Nelson said he had not spoken with Isaacman about it.

• A 65-year-old patient has died of bird flu, Louisiana officials reported on Monday.
• The patient had underlying conditions and was likely infected by exposure to birds.
• This is the first death linked to the current outbreak of H5N1, avian influenza.

Bird flu has claimed its first human death in the US.

A Louisiana patient died from a severe case of the H5N1 avian influenza, state health officials reported on Monday.

The patient, who was over 65 and had underlying conditions, is the only human case of H5N1 in Louisiana.

There is still no sign that the H5N1 virus can spread between people. The Louisiana patient contracted the virus after exposure to wild birds and a non-commercial backyard flock, officials reported.

The bird flu's proliferation through bird and animal populations worldwide has led to many human spillover cases over the years. There have been 939 cases of human H5N1 infections worldwide as of November 2024, according to the World Health Organization. Of those, 464 were fatal.

"I think it's pretty clear that we will continue to see severe disease," Richard Webby, a virologist at St. Jude and director of the WHO animal and bird flu center, told Business Insider. "I guess the real question is are we going to see more? I don't know the answer to that one."

A new variant of H5N1 with concerning mutations

The Louisiana patient, who was hospitalized in late 2024, carried a new version of bird flu, which is unlike the bird flu that has been spreading in cattle across the US, the CDC reported. A teenager in Canada, who was hospitalized with severe bird flu in November, also carried that new version, which is called the D1.1 genotype.

Public-health experts are concerned that H5N1 could develop mutations that allow it to adapt better to infecting mammals. That could set the virus on a path to human-to-human transmission.

Webby said samples of the D1.1 genotype virus "did look like they were starting to develop some of those mutations" after infecting the Louisiana and Canada patients.

Fortunately, the mutated virus did not appear to pass from those two patients to other people.

"To be honest, the last month, six weeks, have made me a little more uneasy about the situation," Webby said.

The Louisiana Department of Health said in its report that the public health risk for the general public remains low, but "people who work with birds, poultry or cows, or have recreational exposure to them, are at higher risk."

Still, Webby said the Louisiana case shows that "the risk of catching this virus is not just for those that are in a milking parlor in California," who are some of the most at-risk due to the widespread outbreak in the state's cattle.

Rather, he said, "anywhere where there's birds, there is a risk to individuals who are in contact with those birds."

• Kenyan officials are investigating who owns a mysterious metallic object that fell from the sky.
• The giant ring fell from space, crash-landing into Mukuku Village in Kenya on Wednesday.
• No one was hurt, but space debris poses a serious threat to life on Earth and in space.

On Wednesday, Mukuku Village in Kenya got an unexpected visitor from space.

At about 3 p.m. local time, a large metallic ring weighing about 1,100 pounds and measuring 8 feet in diameter crash-landed in the village, the Kenya Space Agency said in a statement.

The agency said no one was injured, and that the space debris poses no immediate risk.

Maj. Alois Were, an officer with the Kenya Space Agency, told Citizen TV, a Kenyan news station, that the ring-like object is "possibly from a rocket separation stage."

However, it's unclear whose rocket the ring might belong to. Officials said they had collected pieces from the impact site for further analysis to determine its origins.

Were said that once they determine the owner, the space agency will use the "existing legal mechanisms under international law" to hold the person or organization accountable.

Space debris is usually designed to either burn up in Earth's atmosphere before reaching the ground or land in unpopulated areas, like the ocean. This doesn't always happen, though.

For example, in May 2024, a piece of SpaceX debris as large as a car hood crash-landed on a trail at a mountaintop resort just outside Asheville, North Carolina.

If it had landed on a person hiking the trail that day, it would have certainly killed them, Jonathan McDowell, an astrophysicist at the Harvard and Smithsonian Center for Astrophysics and leading space debris expert, told Business Insider in July.

To date, no one has died from space debris raining from the skies. Perhaps the closest call was in March, when a two-pound piece of debris slightly smaller than a soda can fell from the International Space Station, crashing through a family's roof in Florida. The family is suing NASA over the incident.

Ever since humans started launching objects into space in the late 1950s, there has been a risk that some might fall back to Earth in an unexpected place. As humans launch more objects into space, however, that risk is growing.

Between 2008 and 2017, global space organizations launched an average of 82 orbital rockets a year. That number jumped to an average of about 130 launches a year between 2018 and 2022, according to the US International Trade Commission. In 2024, there were about 250 launches — a new record.

This poses risks on Earth and adds to a long-existing problem in space: space clutter and collisions. There's a lot of trash in space, from dead satellites and astronaut gloves to tiny bits no larger than a grape.

These millions of bits of debris are racing around our planet faster than a bullet. It's gotten so bad that about 1,000 warnings of possible impending collisions are issued daily to satellite operators, physicist Thomas Berger said in a press briefing at December's annual American Geophysical Union meeting.

Berger said a major collision could generate "an unstoppable chain reaction of further collisions, ultimately resulting in a completely filled-up space environment."

If that happens, it could make space unusable.

• The year 2024 had major space events including a total solar eclipse and historic moon landing.
• There were moments, though, that reminded us how challenging space exploration can be.
• Here are the US's biggest moments in space this year and the missions that didn't go so well.

This was a big year for space in the US with many historic firsts.

SpaceX caught a rocket in mid-air. NASA discovered the most promising evidence for ancient life on Mars. And scientists finally got their hands on a perfectly-preserved asteroid sample.

Space exploration, however, is hard, and multiple moments reminded us of that — like a broken Mars copter and glitchy spaceship.

Here are the US's biggest moments in space this year and the missions that taught us outer space is a formidable place.

The year kicked off with two unlucky events.

Astrobotic Technology launched its uncrewed, NASA-funded Peregrine Mission One to the moon on January 8.

The mission suffered a propellant leak after launch and was unable to continue to the moon.

On January 18, Astrobotic's Peregrine lunar lander burned up in Earth's atmosphere.

The same day, NASA's Ingenuity Mars Helicopter had lost a blade, ending its mission.

Ingenuity was the only mission to have ever successfully flown on another planet. It completed 72 flights.

Better news came the following month when Intuitive Machines launched its NASA-funded IM-1 mission to the moon.

On February 22, IM's Odysseus spacecraft became the first private craft to soft-land on the moon.

The landing marked the US's first return to the lunar surface in over 50 years, since Apollo 17.

After landing, Odysseus tipped on its side, disrupting comms with Earth.

IM hopes to land a second spacecraft on the moon in January 2025.

Lunar landings weren't the only major moment for the moon this year.

On April 8, it slipped in front of the sun offering millions of people in the US a total solar eclipse.

The rare event was the last time a total solar eclipse would be visible from the US until 2044.

In June, Boeing launched two astronauts to the International Space Station on its Starliner spacecraft for the first time.

The two astronauts, Suni Williams and Butch Wilmore, have been stuck on the ISS ever since after Starliner suffered engine issues.

Meanwhile, NASA's first year-long simulated Mars mission, CHAPEA-1, ended on July 6. The four crew members were released after living together in a 1,700 sq. ft. habitat for 378 days.

NASA CHAPEA missions are designed to study how humans may fare physically and mentally on long-duration space missions. CHAPEA-2 is scheduled to start in the spring of 2025.

After months of deliberation, NASA and Boeing sent Starliner back to Earth without Williams and Wilmore.

Four days later, on September 10, SpaceX launched perhaps its most historic crewed mission yet: Polaris Dawn.

Polaris Dawn carried four commercial astronauts 870 miles into space — farther than any human had been since NASA's Apollo missions.

The historic mission included the first commercial spacewalk ever. "Everything in that environment is trying to kill you," Jared Isaacman who led the mission, told Business Insider's Ana Altchek.

"You have all these extra senses kind of fusing together, and you get, I think, more of an appreciation for just how hostile and unwelcoming space is," Isaacman said about being outside of the capsule during the spacewalk.

Shortly after Polaris Dawn successfully returned to Earth, NASA anticipated an exciting return from its OSIRIS-REx mission.

On September 24, a capsule containing a sample from the asteroid parachuted into Utah.

It marked the first time an asteroid sample was ever collected and returned to Earth.

Early analysis of the sample found carbon and nitrogen — building blocks of life — that could hold clues to how life may have formed on Earth.

NASA's Perseverance rover also earned a major win in the study of ancient life. It found the best potential evidence yet for past life on Mars.

The rover identified a rock with three key features that could point to alien life.

NASA would need to return the sample to Earth to confirm the potentially groundbreaking discovery, but its Sample Return Mission has been tabled due to high costs and wait time.

October was an exciting month, starting with SpaceX's wild "chopsticks" catch on October 13.

The next day, NASA launched its Europa Clipper toward Jupiter. The spacecraft is on a 1.8 billion-mile trajectory to reach Jupiter in April 2030.

Europa Clipper is designed to help continue NASA's exploration of Jupiter after its Juno mission ends, which is set for September 2025.

On December 10, NASA's Perseverance rover finished its 3.5-month-long journey up the side of Jezero Crater, climbing 1,640 vertical feet.

As the year wrapped up, NASA had one more major milestone planned. On December 24, its Parker Solar Probe flew closer to the sun than any spacecraft in history.

• NASA's Parker Solar Probe is about to make its closest approach to the sun.
• The spacecraft will fly within 3.8 million miles of the solar surface.
• The spacecraft is collecting essential data that can help inform forecasting models on Earth.

The fastest human-made object is hurtling toward the sun at this very moment, approaching speeds of 430,000 mph — and on December 24, it's scheduled to make history.

NASA's Parker Solar Probe launched in 2018 and has completed 21 close flybys around the sun. However, its mission on Christmas Eve will be unlike any other.

At 6:53 a.m. ET, the spacecraft is set to fly the closest to the sun of any human-made object. The mission will take it closer than any previously scheduled or planned future approaches.

If all goes to plan, the uncrewed spacecraft will come within 3.8 million miles of the solar surface.

NASA anticipates the probe will experience temperatures of 1,800 degrees Fahrenheit, which shouldn't be an issue since the spacecraft's protective heat shield is designed to withstand temperatures over 2,500 degrees Fahrenheit.

Yes, 3.8 million miles is far by Earth's standards, but it's ridiculously close when you're out in deep space.

It's like if you put the Earth and sun at opposite ends of an American football field: "Parker Solar Probe is on the 4-yard line approaching the sun," Joe Westlake, Director of NASA's Science Mission Directorate's Heliophysics Division, told 6abc Philadelphia.

"It is getting so close that we're actually in the sun's upper atmosphere. We're actually touching the sun with humanity's first mission to a star," Westlake added.

The moment NASA has been waiting for

The Christmas Eve flyby is the moment the mission has been building up to for years.

"This close approach is only possible because of the mission's orbital design," a NASA spokesperson told Business Insider via email.

"The spacecraft had to shed a lot of orbital energy to get this close to the sun, so that's why it took several years," the spokesperson added.

Over the years the Parker Solar Probe, about the size of a small car, has made increasingly close flybys.

For example, in September 2020, it flew within 8.4 million miles of the solar surface. By September 2023, it reached within 4.5 million miles.

When the spacecraft makes these close approaches, it cuts communication with Earth and flies autonomously, guiding itself through the sun's harsh upper atmosphere until it's far enough away to reestablish coms.

NASA last heard from Parker Solar Probe on December 22 and expects to hear from it again around midnight between Thursday and Friday, Nour Rawafi, Parker Solar Probe project scientist at Johns Hopkins Applied Physics Lab, said during a recent NASA livestream.

While flying so close to the sun doesn't hold any promise of discovering alien life there or paving the way for future crewed missions to walk on the solar surface, the Parker Solar Probe's mission is, arguably, more important.

Here's what you need to know about this historic mission and how it could help humanity solve some of the world's biggest questions.

Parker Solar Probe is helping us answer the big questions

It may appear calm and quiet from far away, but the sun is a turbulent sphere of activity. It's got solar flares and massive eruptions that fire fast-moving, charged particles deep into our solar system.

"Without that activity, we would not exist. That activity is really necessary for life to kick off," Rawafi said during NASA's livestream.

So, on a grand scale, understanding how our sun works can help us better understand how life originated on Earth and where it might exist elsewhere in the universe.

Also, by studying our own star up close, we can learn how other stars in the universe interact "with the billions and billions of other planets that may or may not be like our own planets," Alex Young, associate director for science communication in NASA's Heliophysics Science Division, said during the livestream.

Wishing for the biggest explosion ever

Rawafi said the best gift the sun could give scientists during Parker Solar Probe's coming approach is "one of the strongest explosions ever."

The sun is currently at a solar maximum — a period of peak solar magnetic activity lasting one to two years and causing powerful flares, eruptions, and ejections.

Sometimes, the charged particles from these eruptions reach Earth. When that happens, it can disrupt satellites, mess with GPS, and subsequently ground flights. It can also expose astronauts to high levels of space radiation.

As we continue to launch more satellites and people into space, these solar events are a growing threat. Yet, scientists don't have a highly accurate forecasting model for warning satellite operators and astronauts far in advance.

That's why Rawafi wants a big explosion: The probe would be in a perfect position to study the event mere moments after it occurs, offering scientists swaths of data that could help inform and improve forecasting models.

Parker Solar Probe has already collected so much data during its years of operation that it will take decades to study it all, Rawafi said at the American Geophysical Union annual meeting in early December.

According to NASA, the spacecraft is scheduled to complete 24 orbits around the sun, with its last two planned for 2025.

• A 7.0-magnitude earthquake struck off the shore of Northern California Thursday morning.
• Tsunami warnings have been lifted across northern California and southern Oregon.
• Aftershocks are ongoing, and there's a small chance they could outdo the first quake.

A major earthquake struck near California's coast on Thursday, and aftershocks are still ongoing.

The 7.0-magnitude earthquake struck at about 10:44 a.m. Pacific Time. Its epicenter was offshore, about 62 miles west-southwest of Ferndale, California, according to data from the United States Geological Survey.

The USGS website reported more than 35 smaller quakes across that area over the ensuing three hours, of magnitudes ranging from 2.5 to 4.7, including two quakes that occurred inland.

"There's been quite a lot of aftershocks," Harold Tobin, Washington's state seismologist and the director of the Pacific Northwest Seismic Network, told Business Insider.

As of Thursday afternoon, the USGS forecasts up to 130 aftershocks with a magnitude of 3 or higher within the next week, and a 53% chance of aftershocks larger than magnitude 5.

"It's perfectly plausible that there could be a larger aftershock or more than one larger aftershock," Tobin said.

The USGS estimates the odds are 1 in 100 of an aftershock with a magnitude of 7 or greater.

The fault that slipped

The fault region which produced the 7.0 earthquake is a very seismically active one.

It's called the Mendocino triple junction because three different tectonic plates meet there: the Pacific, North American, and Juan de Fuca plates.

It's right between two notorious earthquake zones, at the northern end of the San Andreas fault and the southern end of the Cascadia Subduction Zone. The CSZ has some of the planet's greatest seismic potential, capable of producing quakes as big as 9.0.

The Mendocino triple junction, however, is less impressive.

"Somewhere in the magnitude sevens range is about as big as things seem to get out there," Tobin said.

The region has produced five earthquakes of magnitude 7 or larger in the past century, according to USGS.

The Thursday quake could have slightly increased the chance of other earthquakes along adjacent faults by increasing stress in those areas.

"It's unlikely that it had a really large, significant impact" on those fault systems, though, Tobin said. The odds are "not zero, but very low," he added.

Tsunami scare

The initial quake triggered tsunami warnings and evacuations — which have since been canceled — along the coast of northern California to southern Oregon, including the San Francisco Bay Area.

The warnings lasted about an hour. The National Tsunami Warning Center canceled them around 11:54 a.m. local time, saying there was no longer a threat.

Most likely, the reason there was no tsunami is that the earthquake came from plates moving side-by-side against each other. This is called a strike-slip earthquake. Because the motion was mostly horizontal, and not vertical, it didn't push the ocean above upward to create a wave.

Even so, the warning was "warranted," Tobin said.

"Until we know enough parameters of the earthquake and can verify whether there is or isn't an actual wave, it's wise to have those warnings," he added.

Possible earthquake damage

The USGS also reported on X a "low likelihood of shaking-related fatalities. Some damage is possible and the impact should be relatively localized."

Governor Gavin Newsom declared a state of emergency for three counties in Northern California which were near the offshore epicenter of the quake.

"We're concerned about damage," he said in a press briefing, adding that the declaration would allow the state to "provide more resources."

According to CNN, about 10,000 homes and businesses in Humboldt County — the area nearest the epicenter — were without power immediately after the large quake. As of Thursday afternoon, though, PowerOutage.us reported fewer than 500 customers without power there.

Newsom said that "early damage assessments are being made," but that the state had no additional information to share yet.

This is a developing story, check back for more information.

• Parts of Siberia's landscape are a ticking time bomb.
• Giant craters started mysteriously appearing 10 years ago.
• A team of scientists think they finally know why.

Tucked away in the frigid northern corner of Siberia are giant craters, some deep enough to fit a 15-story building. Scientists observed the first crater in 2014 and have found about 20 more in the years since.

It's been fairly clear from the beginning that the craters are caused by some type of explosion deep underground. What's triggering the explosions is a topic of debate — one that Ana Morgado, a chemical engineer at the University of Cambridge, thinks she and her colleagues have settled.

If their theory is correct, it would mean these types of exploding craters are rare and only form under specific geologic conditions, so there's no risk of something similar showing up in, say, downtown Manhattan.

Their theory also ties these massive eruptions to climate change. As the planet continues to warm, more craters will likely erupt. When this happens, it releases a highly potent greenhouse gas into the atmosphere, which in turn contributes to climate change.

The mysterious case of Siberia's exploding craters

The colder nooks of the world, in places like Siberia and northern Canada, have a subsurface layer of soil called permafrost that's been permanently frozen for millennia. As global temperatures climb, pockets of permafrost are thawing worldwide.

This has led to some spectacular discoveries like a perfectly preserved 30,000-year-old squirrel in Canada and a 46,000 year-old worm in Siberia. It's not just ancient squirrels and worms hiding in permafrost.

Concentrated amounts of the highly explosive greenhouse gas methane are trapped deep underground in the permafrost in ice-like solids called methane hydrates.

Researchers widely agreed that when these hydrates are damaged, they release methane gas, which is what's triggering the explosions in Siberia.

How the hydrates are damaged in the first place, though, is less clear.

Existing theories suggest that warming permafrost, as a result of the warming Arctic, could ultimately destabilize the hydrate layer, releasing explosive methane gas.

"That was the initial idea, and we didn't question it at all at the beginning," Morgado told Business Insider. "What we questioned was that: Okay, you're saying that that is the case, but you don't present a physical model that can explain that. So no math."

When the team tried matching the math with the observations, they found that it would take centuries for the process to trigger an explosion. The Arctic had only been significantly warming over decades.

"So either something else was happening or magnifying this effect," Morgado said in an email.

The team found the missing piece to their puzzle when they learned of past geological surveys that had identified pools of liquid water, called cryopegs, just above the methane hydrates in Siberia.

What's causing the ground to erupt in Siberia

Normally, the cryopegs are stable. Morgado and the team realized that the summer would threaten this stability.

In summer, frozen soil at the surface melts. That meltwater is then pulled down toward the cryopegs via a process called osmosis — the same process that helps water climb against gravity through tall plants.

Osomis was the magnifying effect the researchers were looking for.

With longer, warmer summers in recent years, enough meltwater is available for long enough periods that it's being driven down to the cryopegs on timescales that matched the observations, Morgado said.

Once the meltwater reaches the cryopegs, it's over.

The meltwater increases the pressure inside the cryopegs, just like adding more water to a water balloon. That pressure cracks the soil leading to the surface, which triggers a drastic reverse in pressure. And that pressure change is what damages the methane hydrates, triggering an explosion.

More exploding craters to come

Siberia will likely have more explosive craters in the coming years as global temperatures continue to warm. That's a problem because the methane these explosions release is a highly potent greenhouse gas, which helps drive global temperatures up even more.

It's unclear exactly how much methane these explosions release, but in the grand scheme of climate change, they're a small matter. Thawing permafrost is a larger concern because it contains concentrations of not only methane but also carbon dioxide that is released into the atmosphere when it melts.

Siberia isn't the only place in the world with permafrost.

If the team's theory is correct, it's possible, but unlikely, that other places with permafrost will start erupting the way Siberia has, Morgado said.

"It would need to be very specific that you would have this in another place," Morgado said, adding, "Luckily we are not seeing the entire world, or the entire Arctic, bursting into craters."