The moon exerts a previously unknown tidal force on the “plasma ocean” surrounding Earth’s upper atmosphere, creating fluctuations that are similar to the tides in the oceans, a new study suggests.
In the study, published Jan. 26 in the journal Nature Physics (opens in new tab) , scientists used more than 40 years of data collected by satellites to track the minute changes in the shape of the plasmasphere, the inner region of Earth’s magnetosphere, which shields our planet from solar storms and other types of high-energy particles.
The plasmasphere is a roughly doughnut-shaped blob of cool plasma that sits on top of Earth’s magnetic field lines, just above the ionosphere, the electrically charged part of the upper atmosphere. The plasma, or ionized gas, in the plasmasphere is denser than the plasma in the outer regions of the magnetosphere, which causes it to sink to the bottom of the magnetosphere. The boundary between this dense sunken plasma and the rest of the magnetosphere is known as the plasmapause.
“Given its cold, dense plasma properties, the plasmasphere can be regarded as a ‘plasma ocean,’ and the plasmapause represents the ‘surface’ of this ocean,” the researchers wrote in the paper. The moon’s gravitational pull can distort this “ocean,” causing its surface to rise and fall like the ocean tides.
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The moon is already known to exert tidal forces on Earth’s oceans, crust, near-ground geomagnetic field and the gas within the lower atmosphere. However, until now, nobody had tested to see if there was a tidal effect on the plasmasphere.
To investigate this question, the researchers analyzed data from more than 50,000 crossings of the plasmasphere by satellites belonging to 10 scientific missions, including NASA’s Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. The satellites’ sensors are capable of detecting minute changes in the concentrations of plasma, which allowed the team to map out the exact boundary of the plasmapause in greater detail than ever before.
The satellite crossings occurred between 1977 and 2015, and during this period, there were four complete solar cycles. This information allowed the team to factor in the role of solar activity on Earth’s magnetosphere. Once the sun’s influence was accounted for, it started to become clear that fluctuations in the shape of the plasmapause followed daily and monthly patterns that were very similar to the ocean’s tides, indicating that the moon was the most likely cause of the plasma tides.
The researchers are unsure exactly how the moon causes the plasma tides, but their current best guess is that the moon’s gravity causes perturbations in Earth’s electromagnetic field. But further research is needed to tell for sure.
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The team thinks this previously unknown interaction between Earth and the moon could help researchers understand other parts of the magnetosphere in greater detail, such as the Van Allen radiation belts, which capture highly energetic particles from solar wind and trap them in the outer magnetosphere.
“We suspect that the observed plasma tide may subtly affect the distribution of energetic radiation belt particles, which are a well-known hazard to space-based infrastructure and human activities in space,” the researchers wrote. Better understanding the tides could therefore help to improve work in these areas, they added.
The researchers also want to see if plasma in the magnetospheres of other planets is influenced by those planets’ moons. “These findings may have implications for tidal interactions in other two-body celestial systems,” they wrote.
ESPN baseball reporter. Covered the L.A. Rams for ESPN from 2016 to 2018 and the L.A. Angels for MLB.com from 2012 to 2016.
LOS ANGELES — Clayton Kershaw approached the podium on a blue, circular stage set up in center field at Dodger Stadium on Friday, after the downtown parade he’d always wanted, with his teammates bowing from behind, and the emotions hit him.
“I’m at a loss for words,” Kershaw, his voice cracking, told a crowd of 42,448 people who showed up to celebrate the Los Angeles Dodgers‘ World Series title. “I didn’t have anything to do with this championship, but it feels like I have the best feeling in the world — that I get to celebrate with you guys!”
When the Dodgers last won it all, in 2020, the COVID-19 pandemic prevented them from enjoying most of the pageantry presented to Major League Baseball’s champion, most notably a parade. Kershaw, who had spent his prolonged career chasing a title, never got to fully enjoy a moment that admittedly lifted a massive burden off his shoulders. When the Dodgers beat the New York Yankees in Game 5 of the World Series on Wednesday night, it gave the franchise its first full-season championship since 1988 and provided its players with an opportunity to fully celebrate.
It probably meant most to Kershaw, even if a foot injury prevented him from helping.
“I think in 2020 there was like a sense of relief almost,” Kershaw said. “And this one — especially because my role is pretty limited, just to be able to sit back and enjoy it, you know? I think there’s just a lot more happiness, honestly. Just so happy to be able to celebrate finally. That parade was for this season, and I feel that this season was unique in its own, and we’re gonna celebrate accordingly. But 2020, too — it’s a long time coming. We had a long time coming for this parade. So to be able to finally do it — I think the build-up made it even sweeter, honestly.”
Seven double-decker buses consisting of players, family members and coaches took a two-mile route from Gloria Molina Grand Park near City Hall, down 1st Street and through Grand Avenue before making their way to Dodger Stadium at around 12:30 p.m. PT. Ice Cube, who famously kicked off Game 2 of the World Series last week, greeted them with a rendition of his iconic song “It Was A Good Day.” Dodgers manager Dave Roberts danced alongside him, then went about introducing some of his key players.
Walker Buehler, who recorded the final out, wore Orel Hershiser’s grey road jersey from the 1988 World Series and yelled expletives into the microphone. Kiké Hernández, in many ways the team’s spiritual leader, stirred the crowd by prompting them to yell “we don’t give a f—,” a reference to his line during an on-field, postgame interview after a pennant-clinching victory. Shohei Ohtani navigated the parade with his dog, Decoy, in tow, then spoke English from the stage.
“This is so special for me,” Ohtani told the crowd. “I’m so honored to be here and to be part of this team. Congratulations, Los Angeles. Thank you, fans!”
Some of the biggest cheers went to Freddie Freeman, who willed his way through a litany of injuries in October and ultimately won World Series MVP. Roberts introduced Freeman as someone who “played with one leg and one rib,” a reference to his sprained right ankle and, as ESPN reported Thursday, the broken costal cartilage he sustained the night before the National League Division Series.
Roberts said the team “got out of the woods” with Freeman’s rib issue in the time off between the end of the NL Championship Series and the start of the World Series, helping Freeman launch a Kirk Gibson-style walk-off grand slam in Game 1.
“But he wasn’t nearly close to 100 percent,” Roberts added.
Neither was Kershaw, of course.
The 36-year-old left-hander underwent shoulder surgery last offseason and didn’t make his 2024 debut until late July. Then, in his seventh start, he aggravated a long-standing toe injury. Attempts to return for the postseason only led to other ailments, forcing him out for the stretch run of the season.
On Wednesday, Kershaw said, he’ll undergo surgery to fix his left foot — consisting of a bone spur and a ruptured plantar plate, among other issues — and another procedure to address a meniscus issue in his left knee.
At some point over these next few days, Kershaw will either exercise his player option for 2025 or sign a new contract to return for his 18th season with the Dodgers.
For 17 years, Kershaw established himself as one of the most monumental figures in the franchise’s illustrious history. He won three Cy Young Awards and an MVP, made 10 All-Star teams, became the all-time leader in strikeouts and accumulated the second-most wins. But he was continually part of star-studded Dodger teams that came up short in the playoffs and, fairly or not, shouldered the blame for much of it.
The 2020 championship brought him vindication.
The 2024 championship allowed him to properly celebrate.
“I knew it was gonna be a special day, all the stuff, but it was a little bit more emotional than I expected,” Kershaw said. “It’s a day that I’ll definitely never forget. You know, baseball is just a game. Everybody says that. But I don’t know, man. You look around and you see how much it means to so many different people. It might be baseball, but it means a lot to a lot of different people. I’m no different.”
LOS ANGELES — The Dodgers, including Shohei Ohtani and his dog, celebrated their eighth World Series championship with a downtown parade and a raucous on-field party on Friday.
“This is so special,” said Ohtani, who usually only speaks in his native Japanese but addressed a crowd of 42,458 at Dodger Stadium in English. “I’m so honored to be here. Congratulations, Los Angeles. Thank you, guys.”
Fellow Japanese star Yoshinobu Yamamoto added in English, “Thank you, Dodger fans.”
Rapper Ice Cube kicked off the bash by performing “It Was a Good Day,” with manager Dave Roberts dancing and joining in on the lyrics from a blue circular stage in the middle of the field.
“You guys wanted a parade. We got a parade,” Roberts said. “Guys, let’s get ready to run this back next year, too.”
Players exchanged hugs and back slaps on the stage as blue-and-white confetti drifted in the air and the team’s signature song, “I Love L.A.,” blared. Their children played on the field, with Freddie Freeman‘s 8-year-old son, Charlie, leading some of them in jumping up on the lower retaining wall near the crowd.
Players took turns passing around the Commissioner’s Trophy.
“Who else has more championships than us in the 2020s?” utilityman Kiké Hernández asked. “Absolutely nobody.”
Roberts introduced Freeman as someone who “played with one leg and one rib,” in reference to the first baseman’s injuries.
“I did everything I could to get on the field for you guys and I’m so glad I did because we got a championship now,” Freeman said. “I can’t wait to run this back next year.”
Earlier, seven double-decker buses filled with players, their families and the coaching staff rolled through streets packed on both sides with blue-clad fans. The City of Los Angeles estimated the crowd to be more than 200,000.
“This is incredible,” said Freeman, the World Series MVP. “L.A. really showed out today.”
Several players smoked cigars and drank beer aboard the buses on the sun-splashed day.
“It’s the best thing I’ve ever been part of,” pitcher Clayton Kershaw said. “I’ve never seen this many people in my life. They’re all Dodger fans.”
A shirtless Hernández hung over the front of his bus with a beer in his hand. Ohtani held his dog, Decoy, in his arms with his wife, Mamiko, nearby.
“I’m totally overwhelmed with the amount of fans who are here,” Ohtani said through an interpreter as the bus rolled along. “It’s been an incredible year. I’m so happy that I was able to contribute. The fans and everybody has been so welcoming.”
Asked if he would take his shirt off like Hernández, a smiling Ohtani shook his head and replied in English, “No, never.”
Walker Buehler, who pitched the ninth inning in the Series finale, did a beer bong while wearing Orel Hershiser’s jersey from the team’s 1988 World Series championship.
“This is crazy, man. I love this,” outfielder Teoscar Hernandez said.
Fans cheered and waved at their heroes. The parade occurred on what would have been the 64th birthday of Fernando Valenzuela, the 1981 NL Cy Young Award and Rookie of the Year winner who died days before the World Series began.
The Dodgers defeated the New York Yankees in five games, clinching the title with a 7-6 victory in the Bronx on Wednesday.
A portion of the proceeds from the ticketed stadium event will be donated to the Los Angeles Dodgers Foundation.
Weaver took over from Clay Holmes as Yankees closer in September and finished 7-3 with a 2.89 ERA and four saves, striking out 103 and walking 26 in 84 innings.
The 31-year-old right-hander was 1-0 with a 1.76 ERA and four saves in the postseason as the Yankees won their first American League pennant since 2009 and lost to the Los Angeles Dodgers in the World Series.
He was claimed off waivers by the Yankees from Seattle in September 2023, became a free agent and re-signed with New York in January for a $2 million deal that wound up earning him another $250,000 in performance bonuses.