We’re going through a comic book phase at my house. Since lucking into the comics stash at the library, my 4-year-old refuses any other literary offering. Try as I might to rekindle her love of Rosie Revere, my daughter shuns that scrappy little engineer for Superman every single night.

I know that comic fans abound, but I’ll admit that I get a little lost reading the books. The multi-paneled illustrations, the jumpy story lines and the fact that my daughter skips way ahead make it hard for me to engage. And I imagine that for a preliterate preschooler, that confusion is worse.

There’s evidence to this idea (although it won’t help me force my daughter to choose girl-power science lit over Superman). A recent study found that kids better learn new vocabulary from books when there’s just one picture to see at a time.

Psychologist Jessica Horst and colleague Zoe Flack, both of the University of Sussex in England, read stories to 36 3½-year-olds. These were specially designed storybooks, with pages as big as printer paper. And sprinkled into the text and reflected in the illustrations were a few nonsense words: An inverted, orange and yellow slingshot that mixed things, called a tannin, and a metal wheel used like a rolling pin, called a sprock.

The researchers wanted to know under which reading conditions kids would best pick up the meaning of the nonsense words. In some tests, a researcher read the storybook that showed two distinct pictures at a time. In other tests, only one picture was shown at a time. Later, the kids were asked to point to the “sprock,” which was shown in a separate booklet among other unfamiliar objects.

Kids who saw just one picture at a time were more likely to point to the sprock when they saw it again, the researchers found. The results, published June 30 in Infant and Child Development, show how important pictures can be for preliterate kids, says Horst.

“As parents, it’s easy to forget that children do not look at the written text until they themselves are learning to read,” she says. (This study shows how infrequently preschoolers look at the words.) That means that kids might focus on pictures that aren’t relevant to the words they’re hearing, a mismatch that makes it harder for them to absorb new vocabulary.
Does this mean parents ought to trash all books with multiple pictures on a page? Of course not. Horst and Flack found that for such books, gesturing toward the relevant picture got the word-learning rate back up. That means that parents ought to point at Wonder Woman’s Lasso of Truth or wave at the poor varlet that Shrek steals a lunch from. (Shrek!, the book by William Steig, contains delightful vocabulary lessons for children and adults alike.)

Those simple gestures, Horst says, will help you and your child “literally be on the same page.”

If you could put Uranus’ moon Cressida in a gigantic tub of water, it would float.

Cressida is one of at least 27 moons that circle Uranus. Robert Chancia of the University of Idaho in Moscow and colleagues calculated Cressida’s density and mass using variations in an inner ring of the planet as Uranus passed in front of a distant star. The team found that the density of the moon is 0.86 grams per cubic centimeter and its mass is 2.5×1017 kilograms. The results, reported August 28 on arXiv.org, are the first to reveal details about the moon. Knowing its density and mass helps researchers determine if and when Cressida might collide with another of Uranus’ moons and what will become of both of them.

Voyager 2 discovered Cressida and several other moons when the spacecraft flew by Uranus in 1986. Those moons, and two discovered later, orbit within 20,000 kilometers of Uranus and are the most tightly packed in the solar system.

Such close quarters puts the moons on collision courses. Based on the newly calculated mass and density of Cressida, simulations suggest it will slam into another moon, Desdemona, in a million years.

Cressida’s density suggests it is made of water ice with some contamination by a dark material. If the other moons have similar compositions, the moon collisions may happen in the more distant future than researchers thought. Determining what the moons are made of will also reveal their ultimate fate after a collision: whether they merge, bounce off each other or shatter into millions of pieces.

A newly fabricated material does more than just hold up under pressure. Unlike many ordinary objects that shrink when squeezed, the metamaterial — a synthetic structure designed to exhibit properties not typically found in natural materials — expands at higher pressures.

This counterintuitive material is made up of a grid of hollow 3-D crosses — shaped like six-way pipe fittings — mere micrometers across. When surrounding pressure of air, water or some other substance increases, the crosses’ circular surfaces bow inward. Because of the way these crosses are connected with levers, that warping forces the crosses to rotate and push away from each other, causing the whole structure to expand, says study coauthor Jingyuan Qu, a physicist at Karlsruhe Institute of Technology in Germany.
The researchers were “very clever about how they connected this quite complex set of structural elements,” says Michael Haberman, a mechanical engineer at the University of Texas at Austin, who wasn’t involved in the work.

Qu and colleagues fashioned a microcube of their metamaterial, described in a paper accepted to Physical Review X, from a plasticlike substance, using a microversion of 3-D printing. When the researchers placed the material inside a gas chamber and cranked up the air pressure from one bar (about the atmospheric pressure at sea level) to five bars, the cube’s volume increased by about 3 percent.
Until now, researchers have only described such pressure-expanding metamaterials in mathematical models or computer simulations, says Joseph Grima, a materials scientist at the University of Malta in Msida not involved in the work. The new metamaterial provides “much-needed proof” that this type of stuff can actually be fabricated, he says.

Adjusting the thickness of the crosses’ surfaces could make this new metamaterial more or less expandable: The thicker it is, the less the structure expands. A metamaterial fine-tuned to stay the same size under a wide range of pressures could be used to build equipment that withstands the crushing pressures of the deep sea or the vacuum of outer space.

NASA is going for the gold. Its GOLD mission — short for Global-scale Observations of the Limb and Disk mission — is slated for launch January 25, the agency announced January 4. GOLD will study the zone where Earth’s atmosphere meets outer space. Its goal is to better understand how both solar and terrestrial storms affect the ionosphere, an upper atmosphere region crucial for radio communications.

Earth’s ionosphere, where incoming cosmic and solar rays interact with the atmosphere to create charged particles, extends from about 75 to about 1,200 kilometers above the planet’s surface. From its geostationary orbit 35,000 kilometers high, GOLD will monitor the ionosphere’s density and temperature using an instrument called an ultraviolet imaging spectrograph. Previous satellites have provided snapshots of the ionosphere, but this is the first time an instrument will keep track of changes in the layers through time, collecting data every 30 minutes.

GOLD is the first NASA mission to be launched aboard a commercial communications satellite. NASA plans to launch a complementary mission, the Ionospheric Connection Explorer, later this year. That mission will travel directly through the ionosphere, studying its makeup, density and temperature.

“The strangest place in the whole universe might just be right here.” So says actor Will Smith, narrating the opening moments of a new documentary series about the wonderful unlikeliness of our own planet, Earth.

One Strange Rock, premiering March 26 on the National Geographic Channel, is itself a peculiar and unlikely creation. Executive produced by Academy Award–nominated Darren Aronofsky and by Jane Root of the production company Nutopia and narrated by Smith, the sprawling, ambitious 10-episode series is chock-full of stunningly beautiful images and CGI visuals of our dynamic planet. Each episode is united by a theme relating to Earth’s history, such as the genesis of life, the magnetic and atmospheric shields that protect the planet from solar radiation and the ways in which Earth’s denizens have shaped its surface.
The first episode, “Gasp,” ponders Earth’s atmosphere and where its oxygen comes from. In one memorable sequence, the episode takes viewers on a whirlwind journey from Ethiopia’s dusty deserts to the Amazon rainforest to phytoplankton blooms in the ocean. Dust storms from Ethiopia, Smith tells us, fertilize the rainforest. And that rainforest, in turn, feeds phytoplankton. A mighty atmospheric river, fueled by water vapor from the Amazon and heat from the sun, flows across South America until it reaches the Andes and condenses into rain. That rain erodes rock and washes nutrients into the ocean, feeding blooms of phytoplankton called diatoms. One out of every two breaths that we take comes from the photosynthesis of those diatoms, Smith adds.
As always, Smith is an appealing everyman. But the true stars of the series may be the eight astronauts, including Chris Hadfield and Nicole Stott, who appear throughout the series. In stark contrast to the colorful images of the planet, the astronauts are filmed alone, their faces half in shadow against a black background as they tell stories that loosely connect to the themes. The visual contrast emphasizes the astronauts’ roles as outsiders who have a rare perspective on the blue marble.
“Having flown in space, I feel this connection to the planet,” Stott told Science News . “I was reintroduced to the planet.” Hadfield had a similar sentiment: “It’s just one tiny place, but it’s the tiny place that is ours,” he added.
Each astronaut anchors a different episode. In “Gasp,” Hadfield describes a frightening moment during a spacewalk outside the International Space Station when his eyes watered. Without gravity, the water couldn’t form into teardrops, so it effectively blinded him. To remove the water, he was forced to allow some precious air to escape his suit. It’s a tense moment that underscores the pricelessness of the thin blue line, visible from space, that marks Earth’s atmosphere. “It contains everything that’s important to us,” Hadfield says in the episode. “It contains life.”

Stott, meanwhile, figures prominently in an episode called “Storm.” Instead of a weather system, the title refers to the rain of space debris that Earth has endured throughout much of its history — including the powerful collision that formed the moon (SN: 4/15/17, p. 18). Stott describes her own sense of wonder as a child, watching astronauts land on our closest neighbor — and how the travels of those astronauts and the rocks they brought back revealed that Earth and the moon probably originated from the same place.

It’s glimpses like these into the astronauts’ lives and personalities — scenes of Hadfield strumming “Space Oddity” on a guitar, for example, or Stott chatting with her son in the family kitchen — that make the episodes more than a series of beautiful and educational IMAX films. Having been away from the planet for a short time, the astronauts see Earth as precious, and they convey their affection for it well. Stott said she hopes that this will be the ultimate takeaway for viewers, for whom the series may serve as a reintroduction to the planet they thought they knew so well. “I hope that people will … appreciate and acknowledge the significance of [this reintroduction],” she said, “that it will result in an awareness and obligation to take care of each other.”
Editor’s note: This story was updated on March 19, 2018, to add a mention of a second executive producer.