The concept of touching the Sun can be traced back to the ancient Greek myth of Icarus, but scientists at NASA have turned that idea into a reality. On Dec. 24th, their Parker Solar Probe managed to travel to just within 3.86 million miles (6.1 million kilometers) of the Sun’s surface, a new record. The probe, which is roughly the size of a small car, has now become the human-made object to come closest to touching the Sun among everything our species has created.
“Moving at up to 430,000 miles per hour (692,017 km per hour), the spacecraft endures temperatures up to 1,800 degrees Fahrenheit (982 degrees Celsius) as it flies through the tenuous outer atmosphere of the Sun called the corona to help scientists better understand our closest star,” the scientists write on their website. If the probe were to travel on Earth at that same velocity, it could move from Los Angeles to New York City in only 20 seconds.
Overall, this is the 22nd time the Parker Solar Probe has made a close approach to the Sun. According to the program director, Arik Posner, the solar explorations are part of NASA’s broader ambition to reach new frontiers in space exploration.
“This is one example of NASA’s bold missions, doing something that no one else has ever done before to answer longstanding questions about our universe,” Arik told Earth.com. Because the probe is currently very close to the Sun, scientists are not able to communicate with it, but they hope to receive a beacon tone on Dec. 27th to confirm the probe has survived.
Most people who own a smart watch or fitness watch use a band made of synthetic rubber to hold the device on their wrist. Although the bands are designed to feel comfortable against the skin, a recent study in the journal Environmental Science & Technology Letters found that they may be harmful. This is due to the substances they are made from — known as fluoroelastomers — which can contain large quantities of a dangerous so-called “forever chemical” known as perfluorohexanoic acid (PFHxA); it is unclear the extent to which this can be absorbed through the skin.
PFHxA belongs to a classification of industrial products known as per and polyfluoroalkyl substances (PFAS), which do not biodegrade and resist breaking down after exposure to water and light, hence the nickname forever chemicals. They have been linked to extreme health problems like cancer, high blood pressure and infertility. Despite these risks, PFAS are widely used in products like non-stick cookware, umbrellas, cosmetics, furniture, cleaning chemicals, water-resistant fabrics and stain-resistant coatings. PFHxA specifically is commonly used in pizza boxes, rain jackets, firefighting foam and waterproofing sprays.
While the scientists behind the study weren’t originally looking for PFHxA, the forever chemical “was the most frequently detected compound” within the 22 watch bands analyzed across numerous brands and price points. Lead author Graham F. Peaslee, a physicist at the University of Notre Dame, told Salon that the researchers had not even been aware that PFAS were used in the watch bands until they saw a full-page ad touting them for being made of fluoroelastomer.
“We realized that the general public didn’t recognize fluoroelastomers as a type of PFAS,” Peaslee said. “Like all other forms of polymeric PFAS, we suspected that these materials would also have ‘other’ PFAS readily available together with the fluoropolymer, and we searched for 20 common PFAS.” That’s when they found the surprisingly high concentrations of PFHxA, a forever chemical that can enter the body after being eaten, inhaled, consumed through drinking or absorbed through the skin.
“This was unique in the sense that it was the first time we had found only one PFAS, and that it was at such high concentrations — much higher than we typically find in consumer products,” Peaslee said.
While the scientists didn’t test this with humans, they still reported that the high levels of PFAS in these products “poses an opportunity for significant transfer to the dermis [skin] and subsequent human exposure. Additionally, several of these watch bands were advertised as ‘sports and fitness’ monitors, implying that the wearer may be exercising with them, which means additional sweat contact and open skin pores.”
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Importantly, Peaslee noted that this is one instance in which a forever chemical was not necessary to include as an ingredient.
“There were many wrist bands available that don’t use PFAS and without concern for the toxic shorter-chain PFAS that can be in direct contact with the consumer’s skin,” Peaslee said. “The good news is that the consumer can opt for alternative wrist bands to avoid potential PFAS exposure risks.”
He added, “It is just a question of knowing that they are present — and it is possible to avoid those with fluoroelastomer materials.”
In addition to PFHxA, the nearly endless varieties of PFAS include perfluorooctanoic sulfonic acid (PFOS), hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX Chemicals), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) and perfluorononanoic acid (PFNA). As of 2019, there were more than 4,700 documented PFAS, even though most of them perform the same basic function — making products more resistant to stains, grease and other kinds of damage.
According to Dr. Anna Reade, senior scientist at the Natural Resources Defense Council (NRDC), chemical engineers have created this wide variety of forever chemicals to engage in a practice known as “regrettable substitution.” When certain forever chemicals face increased regulation or notoriety, manufacturers try to have their cake and eat it too (often successfully) by swapping out the specifically banned compound for a slightly different alternative.
“There are two really good examples that are supported by just a ton of evidence now,” Reade told Salon in July, mentioning the two different PFAS known as PFOA (which was used to make teflon) and PFOS (which was used to make Scotchgard).
“When those came under scrutiny, one of the big substitutions was to use a four-carbon version of PFOS instead,” Reade said. “What they did was they just used a different chain length, exactly the same molecule, but just a shorter version of it, a smaller version.”
The final result was that “they switched to that and said it was safe because there wasn’t any data on it,” Reade said. The practice of engaging in regrettable substitution is still prevalent today.
Back when the stars in our universe were initially being formed, they created rotating disks of dust and gas known as protoplanetary disks. These protoplanetary disks slowly congealed into planets — so slowly, in fact, that astronomers speculated all of the protoplanetary disks that once existed have since blown away.
Yet recent images captured by NASA’s James Webb Space Telescope seem to contradict that notion by showing protoplanetary disks in a dwarf galaxy adjacent to our own Milky Way, the Small Magellanic Cloud. Focusing on a cluster known as NGC 346, which contained conditions analogous to those of the early universe, NASA analyzed spectra of light and learned that these stars still have protoplanetary disks.
Although this debunks the previous assumptions about protoplanetary disks, it also confirms earlier images from the mid-2000s from NASA’s Hubble Telescope.
“The Hubble findings were controversial, going against not only empirical evidence in our galaxy but also against the current models,” study leader Guido De Marchi of the European Space Research and Technology Centre in Noordwijk, Netherlands said in a statement. “This was intriguing, but without a way to obtain spectra of those stars, we could not really establish whether we were witnessing genuine accretion and the presence of disks, or just some artificial effects.”
Researchers have two hypotheses as to why these protoplanetary disks persist. The first is that, if these disks form around large gas clouds and form Sun-like stars, it may take a very long time for them to fade away. The second is that NGC 346 is taking more time to dissipate its protoplanetary disks because of radiation pressure being expelled from its stars.
“While this fact is an exclamation point on global warming, it is also telling us that we have much more to learn,” Serreze said. Scientists like Serreze want to learn why the planet is so much warmer than even they had predicted. Dr. Peter Kalmus, a NASA climate scientist who emphasized his opinions are his own, noted that heating is accelerating “and is now substantially more rapid (0.26° C per decade) than it was a decade ago.”
Dr. Ken Caldeira, an atmospheric scientist at the Carnegie Institution for Science’s Department of Global Ecology, observed that from the perspective of scientists who dedicate their careers to studying climate systems, one major question is whether the current temperature spikes occurred because the previous El Niño cycle gave humanity years of relative relief from temperature increases.
“Will 2025 be another record breaking year, or will it be another hot, but not record hot, year?” Caldeira said. “Many scientists think the recent hot years were largely attributable to a super-position of El Niño variability on top of a greenhouse gas-induced warming trend, but some see the recent years as an acceleration in the underlying warming trend.”
Other scientists, including Caldeira, hope that mitigation strategies like carbon restrictions will slowly push back against the warming trend.
This is not to say that scientists do not agree for sure on one important thing: Overwhelming scientific evidence indicates humans are burning fossil fuels at an unsustainable rate, releasing gases such as carbon dioxide and methane into the atmosphere. As these so-called greenhouse gases trap excess heat, they cause extreme weather events like wildfires, hurricanes and droughts, as well as rising sea levels.
As such, 2024’s distinction as the warmest year in human history “underscores the reality that the planet will continue to warm as long as we burn fossil fuels and add carbon pollution to the atmosphere,” Dr. Michael E. Mann, a climatologist from the University of Pennsylvania, told Salon. Dr. Twila Moon, the deputy lead scientist and science communication liaison at the National Snow and Ice Data Center, pointed out that 2024 was also the second hottest year on record in the Arctic, and that the previous nine years were the nine hottest years in a dataset that goes back to 1900.
“This and other indicators show clearly that the Arctic is in a new regime that is overall hotter and wetter,” Moon said. “Every year in the Arctic now looks dramatically different than even a couple of decades ago. Yet, this new regime is not a new normal because human-caused climate change will continue to bring rapid and ongoing change to the Arctic, and our entire globe.”
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These statistics are more than abstract trivia — they will have a direct impact on the lives of human beings everywhere. For example, 2024 had the deadliest hurricane season in two decades, when Hurricane Katrina hit.
“This underscores how hurricanes are becoming more intense and more deadly as the planet continues to warm,” Mann said. In addition to causing more than 400 deaths, the 2024 Atlantic hurricane season was accompanied by 24 climate change-exacerbated weather disasters in the United States alone that each racked up more than $1 billion in damages. These events included devastating storms like Hurricane Milton and Hurricane Helene.
“This underscores the profound impact that human-caused climate change is already having in the form of devastating extreme weather events that threaten our economy and, increasingly, our lives,” Mann said. These impacts are likely to continue worsening, with Moon pointing out that global fossil fuel emissions are set to reach a new record in 2024.
“This human release of heat-trapping gasses is the primary cause of the increases in extreme weather, flood, drought, heatwaves and generally ‘weird weather’ that we are all experiencing,” Moon said. “It is well known that reducing these emissions is key to minimizing risk and damage into the future. And how to achieve these reductions is well mapped out, with the technology to do it. The pressure is now focused on social, cultural, business and political will.”
Caldeira echoed Moon’s observation about the need for America’s leaders to be serious about the threat posed by climate change.
“On the politics side, the big question is what Trump and the MAGA gang will do to Biden’s legislative achievements in the climate arena,” Caldeira said, referring to President Joe Biden’s various executive and legislative reforms intended to address climate change.
“One view is that the drive for vengeance and destruction (and tax breaks!) is so strong that they will try to eliminate the incentives that were created in the infrastructure and inflation reduction laws,” Caldeira said. “Another view is that since, reportedly, 85% of the benefit accrues to Republican districts, this is essentially a subsidy from blue districts to red districts that the Republicans might not want to give up.”
Kalmus is cynical about the future. He pointed out that at the 2024 United Nations Climate Change Conference, more than 1,700 fossil fuel lobbyists were present to push back against efforts to curb carbon emissions.
“Everything is getting worse, fast — and instead of stopping it, the billionaire class has the pedal to the floor,” Kalmus said. “This will set the stage for reduced habitability on our planet for an extremely long time. Biodiversity could take millions of years to recover. It could lead to billions of human deaths, unimaginable suffering, and limit the possibilities for our species far into the future.”
“This human release of heat-trapping gasses is the primary cause of the increases in extreme weather, flood, drought, heatwaves and generally ‘weird weather’ that we are all experiencing,” Moon said. “It is well known that reducing these emissions is key to minimizing risk and damage into the future. And how to achieve these reductions is well mapped out, with the technology to do it. The pressure is now focused on social, cultural, business and political will.”