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The moon is shrinking — also, moonquakes are a thing
A new NASA report shakes up lunar geology.
- The moon is indeed shrinking. It has been since it formed.
- The shrinking is producing thousands of fault lines.
- Archived seismometer data from Apollo missions show moonquakes.
If you're looking up at a bright full moon and notice it's getting smaller, you're so slightly right that you're closer to being wrong. The moon is shrinking, but only very slowly, and it always has been since its formation, from which it's still cooling down. You've never seen it when it wasn't shrinking.
NASA has just announced, though, that this gradual reduction in size is producing moonquakes. The seemingly lifeless satellite is actually pretty dynamic from a geological point of view, a surprise to the scientific community. Blame shrinkage. Also the pull of earth's gravity.
The research was published May 13 in Nature Geoscience.
In the beginning, revised
Image source: SueC/Shutterstock
We don't really know how the moon formed, but there are suspicions, and the leading theory is that a Mars-sized object slammed into the Earth about 4.5 billion years ago. The object itself, as well as debris from Earth, was ejected into Earth orbit as a molten satellite that's been slowly cooling ever since.
It took about 100 million years for it to crystallize into rocks, with the least dense of them floating upward in the slurry to form the moon's crust and surface. As of this writing, NASA's About the moon webpage says that, "Since the ancient time of volcanism, the arid, lifeless Moon has remained nearly unchanged." They'll likely update that soon — we know now that's it's not true.
Spotted from orbit
Signs of movement: Arrows show boulder fields, patches of relatively high bright soil or regolith.
Image source: NASA/GSFC/Arizona State University/Smithsonian
Orbiting the moon as you read this is NASA's Lunar Reconnaissance Orbiter (LRO), which was launched in June 2009 and has been taking pictures of the Moon's surface since it arrived in lunar orbit a year and four days later.
Captured by its high-resolution 0.5–2m per pixel cameras were a "vast network" of scarps that indicated a variety of interactions between thrust faults. In addition, the faults' crisp appearance, as well as other characteristics, suggest that they're pretty young in geological terms, less than 50 million years old. Though their existence was already known — Apollo 17's Astronauts Eugene Cernan and Harrison Schmitt had to zig-zag their rover up and over the cliff face of one — the sheer number of faults, in the thousands, and their complexity was only made clear by LRO.
NASA compares the faults to the wrinkles formed on a grape's skin as it shrinks into a raisin. The main difference is that where a raisin's skin is soft and pliable, the Moon's crust is brittle and thus fractures and cracks as the Moon continues to cool and shrink at a rate of about 150 feet every few hundred million years.
Digging through Apollo data
Buzz Aldrin deploys a seismometer during the Apollo 11 mission.
Image source: NASA
To gain a fuller understanding of their origin, a team of scientists led by Thomas Watters, senior scientist in the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum took a closer look at data from four seismometers left on the moon by the Apollo 12, 14, 15 and 16 missions at their landing sites. While the Apollo 11 device was active only for about three weeks, the others recorded 28 shallow moonquakes from 1969 to 1977, and there's no reason to think the quakes have stopped since then.
Watters' team developed an algorithm for identifying the quake epicenters from the seismometers' data, and found that at least eight of them were within 30 kilometers of a visible scarps, lending support to the idea that movement of those scarps created the moonquakes. "We think it's very likely that these eight quakes were produced by faults slipping as stress built up when the lunar crust was compressed by global contraction and tidal forces," Watters summarizes, "indicating that the Apollo seismometers recorded the shrinking moon and the moon is still tectonically active." These were not all subtle temblors, either. "Some of these quakes can be fairly strong, around five on the Richter scale."
The algorithm also revealed that six of the eight quakes occurred when the Earth's tidal pull on the Moon was at its maximum, when the moon was at its farthest point, or apogee, from Earth. It's likely that at these times the Moon's crust is under exceptional stress, and so it's more likely for fault slips to occur.
An interesting sidetone is that China's Chang'e-4 dark-side lunar mission may have just found bits of mantle rock on the moon's surface, perhaps a sign of continued geological movement of the Moon's crust and mantle.
Lee Lincoln Scarp at the Apollo 17 Landing Site
Old data, new insight
As LRO Project Scientist John Keller of NASA's Goddard Space Flight Center in Maryland points out, "It's really remarkable to see how data from nearly 50 years ago and from the LRO mission has been combined to advance our understanding of the moon, while suggesting where future missions intent on studying the Moon's interior processes should go."
Innovation in manufacturing has crawled since the 1950s. That's about to speed up.
Health officials in China reported that a man was infected with bubonic plague, the infectious disease that caused the Black Death.
- The case was reported in the city of Bayannur, which has issued a level-three plague prevention warning.
- Modern antibiotics can effectively treat bubonic plague, which spreads mainly by fleas.
- Chinese health officials are also monitoring a newly discovered type of swine flu that has the potential to develop into a pandemic virus.
Bacteria under microscope
needpix.com<p>Today, bubonic plague can be treated effectively with antibiotics.</p><p style="margin-left: 20px;">"Unlike in the 14th century, we now have an understanding of how this disease is transmitted," Dr. Shanthi Kappagoda, an infectious disease physician at Stanford Health Care, told <a href="https://www.healthline.com/health-news/seriously-dont-worry-about-the-plague#Heres-how-the-plague-spreads" target="_blank">Healthline</a>. "We know how to prevent it — avoid handling sick or dead animals in areas where there is transmission. We are also able to treat patients who are infected with effective antibiotics, and can give antibiotics to people who may have been exposed to the bacteria [and] prevent them [from] getting sick."</p>
This plague patient is displaying a swollen, ruptured inguinal lymph node, or buboe.
Centers for Disease Control and Prevention<p>Still, hundreds of people develop bubonic plague every year. In the U.S., a handful of cases occur annually, particularly in New Mexico, Arizona and Colorado, <a href="https://www.cdc.gov/plague/faq/index.html" target="_blank">where habitats allow the bacteria to spread more easily among wild rodent populations</a>. But these cases are very rare, mainly because you need to be in close contact with rodents in order to get infected. And though plague can spread from human to human, this <a href="https://www.healthline.com/health-news/seriously-dont-worry-about-the-plague#Heres-how-the-plague-spreads" target="_blank">only occurs with pneumonic plague</a>, and transmission is also rare.</p>
A new swine flu in China<p>Last week, researchers in China also reported another public health concern: a new virus that has "all the essential hallmarks" of a pandemic virus.<br></p><p>In a paper published in the <a href="https://www.pnas.org/content/early/2020/06/23/1921186117" target="_blank">Proceedings of the National Academy of Sciences</a>, researchers say the virus was discovered in pigs in China, and it descended from the H1N1 virus, commonly called "swine flu." That virus was able to transmit from human to human, and it killed an estimated 151,700 to 575,400 people worldwide from 2009 to 2010, according to the Centers for Disease Control and Prevention.</p>There's no evidence showing that the new virus can spread from person to person. But the researchers did find that 10 percent of swine workers had been infected by the virus, called G4 reassortant EA H1N1. This level of infectivity raises concerns, because it "greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses," the researchers wrote.
So far, 30 student teams have entered the Indy Autonomous Challenge, scheduled for October 2021.
- The Indy Autonomous Challenge will task student teams with developing self-driving software for race cars.
- The competition requires cars to complete 20 laps within 25 minutes, meaning cars would need to average about 110 mph.
- The organizers say they hope to advance the field of driverless cars and "inspire the next generation of STEM talent."
Indy Autonomous Challenge<p>Completing the race in 25 minutes means the cars will need to average about 110 miles per hour. So, while the race may end up being a bit slower than a typical Indy 500 competition, in which winners average speeds of over 160 mph, it's still set to be the fastest autonomous race featuring full-size cars.</p><p style="margin-left: 20px;">"There is no human redundancy there," Matt Peak, managing director for Energy Systems Network, a nonprofit that develops technology for the automation and energy sectors, told the <a href="https://www.post-gazette.com/business/tech-news/2020/06/01/Indy-Autonomous-Challenge-Indy-500-Indianapolis-Motor-Speedway-Ansys-Aptiv-self-driving-cars/stories/202005280137" target="_blank">Pittsburgh Post-Gazette</a>. "Either your car makes this happen or smash into the wall you go."</p>
Illustration of the Indy Autonomous Challenge
Indy Autonomous Challenge<p>The Indy Autonomous Challenge <a href="https://www.indyautonomouschallenge.com/rules" target="_blank">describes</a> itself as a "past-the-post" competition, which "refers to a binary, objective, measurable performance rather than a subjective evaluation, judgement, or recognition."</p><p>This competition design was inspired by the 2004 DARPA Grand Challenge, which tasked teams with developing driverless cars and sending them along a 150-mile route in Southern California for a chance to win $1 million. But that prize went unclaimed, because within a few hours after starting, all the vehicles had suffered some kind of critical failure.</p>
Indianapolis Motor Speedway
Indy Autonomous Challenge<p>One factor that could prevent a similar outcome in the upcoming race is the ability to test-run cars on a virtual racetrack. The simulation software company Ansys Inc. has already developed a model of the Indianapolis Motor Speedway on which teams will test their algorithms as part of a series of qualifying rounds.</p><p style="margin-left: 20px;">"We can create, with physics, multiple real-life scenarios that are reflective of the real world," Ansys President Ajei Gopal told <a href="https://www.wsj.com/articles/autonomous-vehicles-to-race-at-indianapolis-motor-speedway-11595237401?mod=e2tw" target="_blank">The Wall Street Journal</a>. "We can use that to train the AI, so it starts to come up to speed."</p><p>Still, the race could reveal that self-driving cars aren't quite ready to race at speeds of over 110 mph. After all, regular self-driving cars already face enough logistical and technical roadblocks, including <a href="https://www.bbc.com/news/technology-53349313#:~:text=Tesla%20will%20be%20able%20to,no%20driver%20input%2C%20he%20said." target="_blank">crumbling infrastructure, communication issues</a> and the <a href="https://bigthink.com/paul-ratner/would-you-ride-in-a-car-thats-programmed-to-kill-you" target="_self">fateful moral decisions driverless cars will have to make in split seconds</a>.</p>But the Indy Autonomous Challenge <a href="https://static1.squarespace.com/static/5da73021d0636f4ec706fa0a/t/5dc0680c41954d4ef41ec2b2/1572890638793/Indy+Autonomous+Challenge+Ruleset+-+v5NOV2019+%282%29.pdf" target="_blank">says</a> its main goal is to advance the industry, by challenging "students around the world to imagine, invent, and prove a new generation of automated vehicle (AV) software and inspire the next generation of STEM talent."
A new Harvard study finds that the language you use affects patient outcome.
- A study at Harvard's McLean Hospital claims that using the language of chemical imbalances worsens patient outcomes.
- Though psychiatry has largely abandoned DSM categories, professor Joseph E Davis writes that the field continues to strive for a "brain-based diagnostic system."
- Chemical explanations of mental health appear to benefit pharmaceutical companies far more than patients.
Challenging the Chemical Imbalance Theory of Mental Disorders: Robert Whitaker, Journalist<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="41699c8c2cb2aee9271a36646e0bee7d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/-8BDC7i8Yyw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>This is a far cry from Howard Rusk's 1947 NY Times editorial calling for mental healt</p><p>h disorders to be treated similarly to physical disease (such as diabetes and cancer). This mindset—not attributable to Rusk alone; he was merely relaying the psychiatric currency of the time—has dominated the field for decades: mental anguish is a genetic and/or chemical-deficiency disorder that must be treated pharmacologically.</p><p>Even as psychiatry untethered from DSM categories, the field still used chemistry to validate its existence. Psychotherapy, arguably the most efficient means for managing much of our anxiety and depression, is time- and labor-intensive. Counseling requires an empathetic and wizened ear to guide the patient to do the work. Ingesting a pill to do that work for you is more seductive, and easier. As Davis writes, even though the industry abandoned the DSM, it continues to strive for a "brain-based diagnostic system." </p><p>That language has infiltrated public consciousness. The team at McLean surveyed 279 patients seeking acute treatment for depression. As they note, the causes of psychological distress have constantly shifted over the millennia: humoral imbalance in the ancient world; spiritual possession in medieval times; early childhood experiences around the time of Freud; maladaptive thought patterns dominant in the latter half of last century. While the team found that psychosocial explanations remain popular, biogenetic explanations (such as the chemical imbalance theory) are becoming more prominent. </p><p>Interestingly, the 80 people Davis interviewed for his book predominantly relied on biogenetic explanations. Instead of doctors diagnosing patients, as you might expect, they increasingly serve to confirm what patients come in suspecting. Patients arrive at medical offices confident in their self-diagnoses. They believe a pill is the best course of treatment, largely because they saw an advertisement or listened to a friend. Doctors too often oblige without further curiosity as to the reasons for their distress. </p>
Image: Illustration Forest / Shutterstock<p>While medicalizing mental health softens the stigma of depression—if a disorder is inheritable, it was never really your fault—it also disempowers the patient. The team at McLean writes,</p><p style="margin-left: 20px;">"More recent studies indicate that participants who are told that their depression is caused by a chemical imbalance or genetic abnormality expect to have depression for a longer period, report more depressive symptoms, and feel they have less control over their negative emotions."</p><p>Davis points out the language used by direct-to-consumer advertising prevalent in America. Doctors, media, and advertising agencies converge around common messages, such as everyday blues is a "real medical condition," everyone is susceptible to clinical depression, and drugs correct underlying somatic conditions that you never consciously control. He continues,</p><p style="margin-left: 20px;">"Your inner life and evaluative stance are of marginal, if any, relevance; counseling or psychotherapy aimed at self-insight would serve little purpose." </p><p>The McLean team discovered a similar phenomenon: patients expect little from psychotherapy and a lot from pills. When depression is treated as the result of an internal and immutable essence instead of environmental conditions, behavioral changes are not expected to make much difference. Chemistry rules the popular imagination.</p>