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It’s still too early to pack your bags for TRAPPIST-1. But two new studies probe the likely compositions of the seven Earth-sized worlds orbiting the cool, dim star, and some are looking better and better as places to live (SN: 3/18/17, p. 6).

New mass measurements suggest that the septet probably have rocky surfaces and possibly thin atmospheres, researchers report February 5 in Astronomy & Astrophysics. For at least three of the planets, those atmospheres don’t appear to be too hot for life, many of these same researchers conclude February 5 in Nature Astronomy.
TRAPPIST-1 is about 40 light-years from Earth, and four of its planets lie within or near the habitable zone, the range where temperatures can sustain liquid water. That makes these worlds tempting targets in the search for extraterrestrial life (SN: 12/23/17, p. 25)

One clue to potential habitability is a planet’s mass — something not precisely nailed down in previous measurements of the TRAPPIST-1 worlds. Mass helps determine a planet’s density, which in turn provides clues to its makeup. High density could indicate that a planet doesn’t have an atmosphere. Low density could indicate that a planet is shrouded in a puffy, hydrogen-rich atmosphere that would cause a runaway greenhouse effect.

Using a new computer technique that accounts for the planets’ gravitational tugs on each other, astronomer Simon Grimm of the University of Bern in Switzerland and his colleagues calculated the seven planets’ masses with five to eight times better precision than before. Those measurements suggest that the innermost planet probably has a thick, viscous atmosphere like Venus, Grimm says. The other six, which may be covered in ice or oceans, may have more life-friendly atmospheres. The fourth planet from the star has the same density as Earth and receives the same amount of radiation from its star as Earth, Grimm’s team reports in Astronomy & Astrophysics.

“This is really the cool thing: We have one planet which is very, very similar to the Earth,” Grimm says. “That’s really nice.”
Having an atmosphere could suggest habitability, but not if it’s too hot. So using the Hubble Space Telescope, MIT astronomer Julien de Wit and his colleagues, including some members from Grimm’s team, observed the four middle planets as they passed in front of the star. The team was looking for a signature in near-infrared wavelengths of light filtering through planets’ atmospheres. That would have indicated that the atmospheres were full of heat-trapping hydrogen.

In four different observations, Hubble saw no sign of hydrogen-rich atmospheres around three of the worlds, de Wit and colleagues report in Nature Astronomy. “We ruled out one of the scenarios in which it would have been uninhabitable,” de Wit says.

The new observations don’t necessarily mean the planets have atmospheres, much less ones that are good for life, says planetary scientist Stephen Kane of the University of California, Riverside. It’s still possible that the star’s radiation blew the planets’ atmospheres away earlier in their histories. “That’s something which is still on the table,” he says. “This is a really important piece of that puzzle, but there are many, many pieces.”

Finishing the puzzle may have to wait for the James Webb Space Telescope, scheduled to launch in 2019, which will be powerful enough to figure out all the components of the planets’ atmospheres — if they exist.

Hunter-gatherers and farming villagers don’t write parenting handbooks, much less read them. But parents in WEIRD societies — Western, educated, industrialized, rich and democratic — can still learn a few childrearing lessons from their counterparts in small-scale societies.

It’s not that Western parents and kids are somehow deficient. But we live in a culture that holds historically unprecedented expectations about how to raise children. Examples: Each child is a unique individual who must be allowed to make decisions independently; children are precious and innocent, so their needs are more important than those of adults; and kids need to be protected from themselves by constant adult supervision.
When compared to family life in foraging and farming cultures, and in WEIRD societies only a few decades ago, there is nothing “normal” about parenting convictions such as these.

“Childhood, as we now know it, is a thoroughly modern invention,” says anthropologist David Lancy of Utah State University in Logan. He has studied traditional societies for more than 40 years.

In his book Raising Children: Surprising Insights from Other Cultures, Lancy examines what’s known about bringing up kids in hunter-gatherer groups and farming villages. Among the highlights:

Babies are usually regarded as nonpeople, requiring swaddling and other special procedures over months or years to become a human being.
Children are typically the lowest-ranking community members.
Because kids can’t feed and protect themselves, they accumulate a moral debt to their elders that takes years of hard work to repay.
If that sounds harsh to WEIRD ears, withhold judgment before considering these child-rearing themes from traditional cultures.

Allow for make-believe about real life
Hunter-gatherer and village kids intently observe and imitate adults (SN: 2/17/18, p. 22). Playtime often consists of youngsters of various ages acting out and even parodying adult behaviors. Virtually everything, from relations between the sexes to religious practices, is fair game. Kids scavenge for props, assign each other roles and decide what the cast of characters will say.

Western children would benefit from many more chances to play in unsupervised, mixed-age groups, Lancy says.

Let kids play collaborative games
A big advantage of play groups of kids of all ages is that they become settings for games in which kids negotiate the rules. Until recently, these types of games, such as marbles, hopscotch and jump rope, were common among U.S. children.

Not anymore, at least not in neighborhoods dominated by adult-supervised play dates and sports teams. Sure, tempers can flare as village youngsters hash out rules for marbles or jacks. But negotiations rarely go off the rails. Older kids handicap themselves so that younger children can sometimes win a game. Concessions are made even for toddlers.

The point is to maintain good enough relations to keep adults from intruding. In modern societies, Lancy suspects, bullying flourishes when kids don’t learn early on how to play collaboratively.

Put young children to work
In most non-WEIRD societies, miniature and cast-off tools and utensils, including knives, are the toys of choice for kids of all ages. Play represents a way to prepare for adult duties and, when possible, work alongside adults as helpers.

Western parents can find ways for preschoolers to help out around the house, but it demands flexibility and patience. Lancy suggests making allowances for a 3-year-old who mixes up socks when sorting the laundry. Maybe paper plates are needed until a kitchen helper becomes less apt to drop them.

Still, carefully selected jobs for 3- and 4-year-olds promote a sense of obligation and sympathy toward others, Lancy says. Western kids given chances to help adults early on may, like their non-WEIRD peers, willingly perform chores at later ages, he predicts.

Whether children live in city apartments or forest huts, having the freedom to explore and play with no adults around proves an antidote to boredom. Lancy recalls how boredom-busting works from his own early childhood in rural Pennsylvania during the 1950s. His family lived in a house bordering a river. Lancy would sit on the river bank for up to an hour at a time. His mother liked to tell visitors a story that, when asked what he had been doing, the boy replied “watching the ‘flections.”

If you’ve ever felt the urge to tap along to music, this research may strike a chord.

Recognizing rhythms doesn’t involve just parts of the brain that process sound — it also relies on a brain region involved with movement, researchers report online January 18 in the Journal of Cognitive Neuroscience. When an area of the brain that plans movement was disabled temporarily, people struggled to detect changes in rhythms.

The study is the first to connect humans’ ability to detect rhythms to the posterior parietal cortex, a brain region associated with planning body movements as well as higher-level functions such as paying attention and perceiving three dimensions.
“When you’re listening to a rhythm, you’re making predictions about how long the time interval is between the beats and where those sounds will fall,” says coauthor Jessica Ross, a neuroscience graduate student at the University of California, Merced. These predictions are part of a system scientists call relative timing, which helps the brain process repetitive sounds, like a musical rhythm.

“Music is basically sounds that have a structure in time,” says Sundeep Teki, a neuroscientist at the University of Oxford who was not involved with the study. Studies like this, which investigate where relative timing takes place in the brain, could be crucial to understanding how the brain deciphers music, he says.

Researchers found hints of the relative timing system in the 1980s, when observing that Parkinson’s patients with damaged areas of the brain that control motion also had trouble detecting rhythms. But it wasn’t clear that those regions were causing patients’ difficulty with timing — Parkinson’s disease can wreak havoc on many areas of the brain.
Ross and her colleagues applied magnetic pulses to two different areas of the brain in 25 healthy adults. Those areas — the posterior parietal cortex and the supplementary motor area, which controls movement — were then unable to function properly for about an hour.

Suppressing activity in the supplementary motor area caused no significant change in participants’ ability to follow a beat. But when the posterior parietal cortex was suppressed, all of the adults had trouble keeping rhythm. For example, when listening to music overlaid with beeps that were on the beat as well as off the beat, participants frequently failed to differentiate between the two. This finding suggests the posterior parietal cortex is necessary for relative timing, the researchers say.

The brain has another timing system that was unaffected by the suppression of activity in either brain region: discrete timing, which keeps track of duration. Participants could distinguish between two notes held for different amounts of time. Ross says this suggests that discrete timing is governed by other parts of the brain. Adults also had no trouble differentiating fast and slow tempos, despite tempo’s connection to rhythm, which might imply the existence of a third timing system, Ross says.

Research into how the brain processes time, sound and movement has implications for understanding how humans listen to music and speech, as well as for treating diseases like Parkinson’s.

Still, many questions about the brain’s timing mechanisms remain (SN: 07/25/15, p. 20): What are the evolutionary origins of different timing mechanisms? How do they work in conjunction to create musical perception? And why do most other animals seem to lack a relative timing system?

Scientists are confident that they will have answers — all in good time.

Fishing has left a hefty footprint on Earth. Oceans cover more than two-thirds of the planet’s surface, and industrial fishing occurred across 55 percent of that ocean area in 2016, researchers report in the Feb. 23 Science. In comparison, only 34 percent of Earth’s land area is used for agriculture or grazing.

Previous efforts to quantify global fishing have relied on a hodgepodge of scant data culled from electronic monitoring systems on some vessels, logbooks and onboard observers. But over the last 15 years, most commercial-scale ships have been outfitted with automatic identification system (AIS) transceivers, a tracking system meant to help ships avoid collisions.
In the new study, the researchers examined 22 billion AIS positions from 2012 through 2016. Using a computer trained with a type of machine learning, the team then identified more than 70,000 fishing vessels and tracked their activity.

Much of the fishing was concentrated in countries’ exclusive economic zones — ocean regions within about 370 kilometers of a nation’s coastline — and in certain hot spots farther out in the open ocean, the team found. Such hot spots included the northeastern Atlantic Ocean and the nutrient-rich upwelling regions off the coasts of South America and West Africa.

Surprisingly, just five countries — China, Spain, Taiwan, Japan and South Korea — accounted for nearly 85 percent of fishing efforts on the high seas, the regions outside of any country’s exclusive economic zone.

Tracking the fishing footprint in space and time, the researchers note, can help guide marine environmental protections and international conservation efforts for fish. That may be particularly important in a time of rapid change due to rising ocean temperatures and increasing human activity on the high seas.