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China's lunar rover nabs the first surface photos of the moon's 'dark' side
It's the first time humans have landed a spacecraft on the far side of the moon.
- China's lunar rover is outfitted with cameras and other equipment designed to collect data from a crater near the moon's southern pole.
- Studying the far side of the moon could provide scientists with a better understanding of what gave rise to the conditions necessary for life on Earth.
- In addition to scientific discoveries, China also likely plans to use the data from its mission to better plan future mining operations.
China successfully landed a spacecraft on the far side of the moon on Wednesday, marking a world first that comes just 16 years after the nation launched its first astronaut into space.
Speaking with China Global Television Network, a state-operated English TV channel, spaceflight expert Yang Yuguang, who is affiliated with the China Aerospace Science & Industry Corporation, said the new feat is "a milestone" for the nation's lunar exploration project.
In the United States, NASA Administrator Jim Bridenstine called the landing "an impressive accomplishment" on Twitter.
The unmanned spacecraft, dubbed the Chang'e 4, is carrying a 300-pound rover that's designed to use cameras, ground-penetrating radar and spectrometers to collect data from the lunar surface, particularly from the Von Kármán crater, the oldest and deepest on the moon. This crater lies in the South Pole-Aitken Basin, a 1,600-mile-wide impact crater that was likely formed when a massive asteroid collided with the moon and brought some material from its upper mantle to the surface.
What does the far side of the moon look like? China's Chang'e-4 probe gives you the answer. It landed on the neve… https://t.co/IBQmC4X5ei— China Xinhua News (@China Xinhua News)1546492453.0
China's mission control are expected to ensure the rover is operating effectively before attempting to collect data. China, whose burgeoning space program launched more rockets into orbit than any other nation in 2018, hopes to use its rover to learn more about the origins and evolution of the moon. In coming years, the Chang'e 5 and 6 missions are scheduled to retrieve lunar samples and bring them back to Earth.
Congratulations to China’s Chang’e-4 team for what appears to be a successful landing on the far side of the Moon.… https://t.co/tpZ16xCZpz— Jim Bridenstine (@Jim Bridenstine)1546488896.0
Why can't we see the far side of the moon?
The answer isn't because the moon doesn't rotate — it does — but rather because the moon's rotational period matches its orbital period around the Earth. In other words, the moon takes about 27 days to orbit our planet once, and during that same time period the moon also rotates around its own axis exactly once. So, only one side of the moon ever faces Earth.
(By the way, calling it the "dark side of the moon" isn't accurate because the far side of the moon gets plenty of sunlight.)
Interestingly, the moon and the Earth weren't always in synch with each other. But over billions of years, the pull of Earth's gravity actually changed the shape of the moon, forming slight bulges in some places. Now, these bulges help keep the moon oriented toward our planet at all times. What's more, the moon's gravity also exerts itself on the Earth, causing ocean tides to shift as the Earth rotates.
In 1959, humans caught the first glimpse of the far side of the moon after the Soviet spacecraft Luna 3 snapped a couple dozen photographs in a landmark mission.
The images proved what many scientists had hypothesized: The far side of the moon looks very different from the side we always see because it's been bombarded by countless asteroids over the eons, a result of constantly facing the cosmos.
During the Apollo 8 mission in 1968, NASA astronaut Bill Anders described the far of the moon to mission control:
The backside looks like a sand pile my kids have been playing in for a long time... It's all beat-up, no definition... Just a lot of bumps and holes.
Here's a more recent photo of the far side of the moon, taken by NASA's Lunar Reconnaissance Orbiter in 2011.
Why study the far side of the moon?
One goal of China's mission to determine approximately when the South Pole-Aitken Basin was created. Interestingly, the bombardment of the southern region of the moon by asteroids seems to have occurred around the same time life appeared on Earth. This might give scientists clues about what creates the conditions for life on planets.
"Understanding the intensity and timing of the bombardment is important as… that was going on about the same time that life appeared on Earth," Ian Crawford, professor of planetary science and astrobiology at Birkbeck University, London, told The Guardian. "The Earth has lost its record of that very early time."
In addition to studying the basin, China's lander will also conduct a biology experiment that will see whether plant seeds will germinate and silkworm eggs will hatch in the moon's low gravity. Outside of science, China likely has other motivations: collecting data for future mining operations.
"This is a major achievement technically and symbolically," Namrata Goswami, an independent analyst who wrote about space for the Defense Department's Minerva Research Institute, told the New York Times. "China views this landing as just a stepping stone, as it also views its future manned lunar landing, since its long-term goal is to colonize the moon and use it as a vast supply of energy."
Melting ice is turning up bodies on Mt. Everest. This isn't as shocking as you'd think.
- Mt. Everest is the final resting place of about 200 climbers who never made it down.
- Recent glacial melting, caused by climate change, has made many of the bodies previously hidden by ice and snow visible again.
- While many bodies are quite visible and well known, others are renowned for being lost for decades.
People die trying to reach the top of Mt. Everest. While about 5,000 people have gotten to the top and came back down to tell the tale, 300 have not and 200 bodies remain on the mountain. Many of these bodies have been covered by snow and ice over the years, but now with glaciers melting due to climate change some of the long-hidden bodies are reportedly becoming visible again.
Ang Tshering Sherpa, former president of Nepal Mountaineering Association, told the BBC: "Because of global warming, the ice sheet and glaciers are fast melting and the dead bodies that remained buried all these years are now becoming exposed. We have brought down dead bodies of some mountaineers who died in recent years, but the old ones that remained buried are now coming out."
The ice on Everest is melting fast, in 2016 the Nepalese Army had to be called in to drain lakes swollen with glacial-melt that threatened to flood. The Khumbu Glacier is melting so fast that ponds are forming and linking up to create small lakes. Not all the bodies that turn up are made visible by global warming though, glaciers move and snow drifts shift over time so previously hidden bodies are always at risk of coming back into view.
Why leave the bodies there at all? Why not bring people down as soon as they die?
It costs a lot of money to go get a body on the highest mountain in the world, up to $80,000 to be precise. Then there is the problem of actually doing it, since some attempts to retrieve bodies are forced by difficult conditions to abandon their efforts.
Some people, such as mountaineer Alan Arnette, argue that the bodies should be left there. He told the BBC, "Most climbers like to be left on the mountains if they died. So it would be deemed disrespectful to just remove them unless they need to be moved from the climbing route or their families want them."This doesn't stop people from wanting the bodies taken down or dealt with in other ways. David Sharp's body was moved out of sight in 2007. George Mallory's body took 75 years to find and was given an Anglican burial in 1999. Over time, the elements often move bodies away from the main routes up the mountain to more isolated areas where they remain undisturbed.
Everest’s chilling landmarks
The bodies that remain in view are often used as waypoints for the living. Some of them are well-known markers that have earned nicknames.
For instance, the image above is of "Green Boots," the unidentified corpse named for its neon footwear. Widely believed to be the body of Tsewang Paljor, the remains are well known as a guide point for passing mountaineers. Perhaps it is too well known, as the climber David Sharp died next to Green Boots while dozens of people walked past him — many presuming he was the famous corpse.
A large area below the summit has earned the discordant nickname "Rainbow Valley" for being filled with the bright and colorfully dressed corpses of maintainers who never made it back down. The sight of a frozen hand or foot sticking out of the snow is so common that Tshering Pandey Bhote, vice president of Nepal National Mountain Guides Association claimed: "Most climbers are mentally prepared to come across such a sight."
Other bodies are famous for not having been found yet. Andrew "Sandy" Irvine, the climbing partner of George Mallory, may have been one of the first two people to reach the summit of Everest a full 30 years before Edmund Hillary and Tenzing Norgay did it. Since they never made it back down, nobody knows just how close to the top they made it.
Mallory's frozen body was found by chance in the '90s without the Kodak cameras he brought up to record the climb with. It has been speculated that Irvine might have them and Kodak says they could still develop the film if the cameras turn up. Circumstantial evidence suggests that they died on the way back down from the summit, Mallory had his goggles off and a photo of his wife he said he'd put at the peak wasn't in his coat. If Irvine is found with that camera, history books might need rewriting.
As Everest's glaciers melt its morbid history comes into clearer view. Will the melting cause old bodies to become new landmarks? Will Sandy Irvine be found? Only time will tell.
It could lead to a massive uptake in those previously hesitant.
A financial shot in the arm could be just what is needed for Americans unsure about vaccination.
On May 12, 2021, the Republican governor of Ohio, Mike DeWine, announced five US$1 million lottery prizes for those who are vaccinated. Meanwhile, in West Virginia, younger citizens are being enticed to get the shot with $100 savings bonds, and a state university in North Carolina is offering students who get vaccinated a chance to win the cost of housing. Many companies are paying vaccinated employees more money through bonuses or extra paid time off.
The push to get as many people vaccinated as possible is laudable and may well work. But leading behavioral scientists are worried that paying people to vaccinate could backfire if it makes people more skeptical of the shots. And ethicists have argued that it would be wrong, citing concerns over fairness and equity.
As a behavioral scientist and ethicist, I draw on an extensive body of research to help answer these questions. It suggests that incentives might work to save lives and, if properly structured, need not trample individual rights or be a huge expense for the government.
In the United States, incentives and disincentives are already used in health care. The U.S. system of privatized health insurance exposes patients to substantial deductibles and copays, not only to cover costs but to cut down on what could be deemed as wasteful health care – the thinking being that putting a cost to an emergency room visit, for example, might deter those who aren't really in need of that level of care.
In practice, this means patients are encouraged to decline both emergency and more routine care, since both are exposed to costs.
Paying for health behaviors
In the case of COVID-19, the vaccines are already free to consumers, which has undoubtedly encouraged people to be immunized. Studies have shown that reducing out-of-pocket costs can improve adherence to life-sustaining drugs, whether to prevent heart attacks or to manage diabetes.
A payment to take a drug goes one step further than simply reducing costs. And if properly designed, such incentives can change health behaviors.
And for vaccination in particular, payments have been successful for human papillomavirus (HPV) in England; hepatitis B in the United States and the United Kingdom; and tetanus toxoid in Nigeria. The effects can be substantial: For example, for one group in the HPV study, the vaccination rate more than doubled with an incentive.
For COVID-19, there are no field studies to date, but several survey experiments, including one my group conducted with 1,000 Americans, find that incentives are likely to work. In our case, the incentive of a tax break was enough to encourage those hesitant about vaccinations to say they would take the shot.
Even if incentives will save lives by increasing vaccinations, there are still other ethical considerations. A key concern is protecting the autonomous choices of people to decide what they put into their own bodies. This may be especially important for the COVID-19 vaccines, which – although authorized as likely safe and effective – are not yet fully approved by the Food and Drug Administration.
But already people are often paid to participate in clinical trials for drugs that have not yet been approved by the FDA. Ethicists have worried that such payments may be “coercive" if the money is so attractive as to override a person's free choices or make them worse off overall.
One can quibble about whether the term “coercion" applies to offers of payment. But even if offers were coercive, payments may still be reasonable to save lives in a pandemic if they succeed in greater levels of immunization.
During the smallpox epidemic nearly 100 years ago, the U.S. Supreme Court upheld the power of states to mandate vaccines. Compared with mandating vaccination, the incentives to encourage vaccines seem innocuous.
Exploitation and paternalism
Yet some still worry. Bioethicists Emily Largent and Franklin Miller wrote in a recent paper that a payment might “unfairly" exploit “those U.S. residents who have lost jobs … or slipped into poverty during the pandemic," which could leave them feeling as if they have “no choice but to be vaccinated for cash." Others have noted that vaccine hesitancy is higher in nonwhite communities, where incomes tend to be lower, as is trust in the medical establishment.
Ethicists and policymakers should indeed focus on the poorest members of our community and seek to minimize racial disparities in both health outcomes and wealth. But there is no evidence that offering money is actually detrimental to such populations. Receiving money is a good thing. To suggest that we have to protect adults by denying them offers of money may come across as paternalism.
Some ethicists also argue that the money is better spent elsewhere to increase participation. States could spend the money making sure vaccines are convenient to everyone, for example, by bringing them to community events and churches. Money could also support various efforts to fight misinformation and communicate the importance of getting the shot.
The cost of incentives
Financial incentives could be expensive as a policy solution. As in Ohio, lottery drawings are one way to cap the overall cost of incentives while giving millions of people an additional reason to get their shot.
The tax code could also allow for a no-cost incentive for vaccination. Tax deductions and credits are often designed to encourage behaviors, such as savings or home ownership. Some states now have big budget surpluses and are considering tax relief measures. If a state announced now that such payments would be conditional on being vaccinated, then each person declining the shot would save the government money.
Ultimately, a well-designed vaccination incentive can help save lives and need not keep the ethicists up at night.
Geologists discover a rhythm to major geologic events.
- It appears that Earth has a geologic "pulse," with clusters of major events occurring every 27.5 million years.
- Working with the most accurate dating methods available, the authors of the study constructed a new history of the last 260 million years.
- Exactly why these cycles occur remains unknown, but there are some interesting theories.
Our hearts beat at a resting rate of 60 to 100 beats per minute. Lots of other things pulse, too. The colors we see and the pitches we hear, for example, are due to the different wave frequencies ("pulses") of light and sound waves.
Now, a study in the journal Geoscience Frontiers finds that Earth itself has a pulse, with one "beat" every 27.5 million years. That's the rate at which major geological events have been occurring as far back as geologists can tell.
A planetary calendar has 10 dates in red
Credit: Jagoush / Adobe Stock
According to lead author and geologist Michael Rampino of New York University's Department of Biology, "Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random."
The new study is not the first time that there's been a suggestion of a planetary geologic cycle, but it's only with recent refinements in radioisotopic dating techniques that there's evidence supporting the theory. The authors of the study collected the latest, best dating for 89 known geologic events over the last 260 million years:
- 29 sea level fluctuations
- 12 marine extinctions
- 9 land-based extinctions
- 10 periods of low ocean oxygenation
- 13 gigantic flood basalt volcanic eruptions
- 8 changes in the rate of seafloor spread
- 8 times there were global pulsations in interplate magmatism
The dates provided the scientists a new timetable of Earth's geologic history.
Tick, tick, boom
Credit: New York University
Putting all the events together, the scientists performed a series of statistical analyses that revealed that events tend to cluster around 10 different dates, with peak activity occurring every 27.5 million years. Between the ten busy periods, the number of events dropped sharply, approaching zero.
Perhaps the most fascinating question that remains unanswered for now is exactly why this is happening. The authors of the study suggest two possibilities:
"The correlations and cyclicity seen in the geologic episodes may be entirely a function of global internal Earth dynamics affecting global tectonics and climate, but similar cycles in the Earth's orbit in the Solar System and in the Galaxy might be pacing these events. Whatever the origins of these cyclical episodes, their occurrences support the case for a largely periodic, coordinated, and intermittently catastrophic geologic record, which is quite different from the views held by most geologists."
Assuming the researchers' calculations are at least roughly correct — the authors note that different statistical formulas may result in further refinement of their conclusions — there's no need to worry that we're about to be thumped by another planetary heartbeat. The last occurred some seven million years ago, meaning the next won't happen for about another 20 million years.