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The Moon and the Earth have been dancing around each other since the Moon was first created 4.5 billion years ago, likely in a collision between planet Theia and Earth.

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But the orbits of these two bodies have changed over time. The Moon is getting further away from us, meaning one day far in the future, humanity (or whatever evolves from dogs) will look up and see the last total solar eclipse.

We have an incredibly accurate idea of how fast the Moon is currently moving away from us, thanks to the Lunar Laser Ranging Experiment. The Apollo missions in the 60s and 70s placed reflectors on the surface of the Moon. By aiming lasers at the reflector and measuring the time it takes to be reflected back at Earth, scientists were able to determine the distance between the two points to within around 3 centimeters (1.2 inches). Taking repeated measurements showed us that the Moon is currently moving away from us at a rate of about 3.8 centimeters (1.5 inches) per year.

This hasn’t always been the case. If we take the current rate of recession and project it backwards, the Moon collides with the Earth about 1.5 billion years ago, which is awkward given that the Moon is 3 billion years older than that. 

Instead, we can look at other evidence, such as layers placed down in rock and coral, which can provide estimates of the length of Earth days and the distance to the Moon at various points in history. 

We can also make projections of what happens next. First, say goodbye to the total solar eclipse.

“Over time, the number and frequency of total solar eclipses will decrease,” lunar scientist at NASA’s Goddard Space Flight Center Richard Vondrak said in 2017. “About 600 million years from now, Earth will experience the beauty and drama of a total solar eclipse for the last time.”

The fact that our Moon currently eclipses the Sun in its entirety is a happy accident. The Sun and the Moon look about the same size in the sky as the Sun is about 400 times further away from the Earth than the Moon, and about 400 times bigger in diameter. Four billion years ago, before the Moon drifted to its current orbit, it would have appeared about three times as big as it is now in the sky.

While the Moon will continue to drift, appearing smaller and smaller in the sky, it will never be free of our orbit. The Sun will become a red giant and engulf the Earth before we are properly separated from the Moon’s influence. We shall go down together.

An earlier version of this article was published in 2023.

Employers in science, technology, engineering and mathematics – commonly called the STEM industries – continue to struggle to attract female applicants. In its 2024 jobs report, the National Science Board found that men outnumber women almost 3-to-1 in STEM jobs that require at least a bachelor’s degree and over 8-to-1 in STEM jobs that don’t, such as electrical, plumbing or construction work.

Despite women being just as academically prepared for many STEM roles as men, if not more so, and the fact that STEM jobs offer higher salaries and greater job security than non-STEM jobs, men continue to dominate this section of the workforce.

I am a social scientist who studies the relationship between education, identity and science, and since 2019, I’ve led the Talking Science research and development group. One question we’ve sought to answer is why employers continue to struggle recruiting talented women to the STEM workforce.

Our team recently carried out a study where we discovered that how caregivers, especially mothers, talk about STEM topics may significantly shape their children’s interest in STEM careers.

Are you a math person?

As a researcher, whenever I give a public talk I like to ask the audience, “Who here is not a math person?” Without fail, several hands shoot up faster than if I had asked, “Who wants free money?”

It turns out that most people are well aware of their own relationship to STEM fields and may see themselves as a math, science or “STEM” person, or, commonly, not a STEM person. Researchers like me call this kind of self-identification a “STEM identity,” and almost everyone has one. Although any given person can have a very high STEM identity or a very low one, most individuals fall somewhere in between.

Having a high STEM identity strongly predicts whether a student will choose to pursue a career in STEM. Research shows that if children don’t develop a high STEM identity by eighth grade, they are unlikely to ever pursue a STEM career.

This finding raises the question: What childhood experiences shape children’s STEM identities?

Individuals come to identify with different groups by recognizing characteristics they share with members of those groups. In many cases, people learn about the characteristics of a group through direct experience. For example, elementary-age children often see teaching as a female occupation when they encounter mostly female teachers at their school. Most children, however, never spend enough time with a scientist to form a stereotype directly.

Children learn most of what they know about STEM professionals indirectly through depictions of scientists in their social environment. Once children have formed a stereotype in their minds, they then compare themselves to these stereotypes to determine whether they are, or could be, a STEM person.

In the United States, five decades of the “draw-a-scientist” studies reveal that children asked to depict scientists overwhelmingly draw them as male – illustrating a persistent stereotype linking science and masculinity. While a growing body of research shows that in recent years gender-based stereotypes of STEM workers have decreased significantly, STEM workforce employment patterns contradict this finding.

A missing explanation?

Since social stereotypes about scientists are becoming less gender-biased, our team realized that something else must be causing children to carry male-biased views of STEM into young adulthood. The Talking Science team believed that understanding why some women see themselves as STEM people and want to obtain STEM jobs held the key to understanding the gap between decreasing social stigma and the persistent lack of women in STEM.

To understand this phenomenon more deeply, our team interviewed 20 college students, 13 of whom identified as female. We intentionally selected these students because of their positive STEM identities and enrollment in college STEM programs.

During 60-to-90-minute interviews, we asked participants to list the various people who positively or negatively shaped their academic and professional interests. We then asked students to label each of them as either a “STEM person,” “not a STEM person” or somewhere in between. Finally, we invited each student to explain why they assigned each label.

The students mentioned 102 individuals – including parents, aunts, siblings, friends and teachers – as influential in shaping their STEM identities. Our team then assigned a gender to these individuals based on pronouns and other descriptors the interviewees used.

A gender gap clearly emerged. Women were only about 40% of those described as STEM people and 70% of the individuals described as not STEM people. This latter group almost always included our interviewees’ mothers.

Updating stereotypes about STEM workers

When first examining the data, we assumed that college students didn’t recognize their mothers as STEM people because of gender stereotypes. Some students were reluctant to describe their mothers as STEM people even when both parents worked in STEM professions – in one case, both parents even held the same college STEM degree.

After closer examination, we noticed that a few students labeled their fathers as not a STEM person. These fathers shared one thing in common with mothers labeled the same way: They all played the role of primary caregiver.

Even in cases where mothers or fathers held a college degree in a STEM field, students consistently diminished the STEM identity of the parent who took on the bulk of the child-rearing responsibilities. As a result, we recognized that something other than gender contributed to students’ perceptions of their parents’ STEM identities.

When pressed to describe why they did not see their primary caregivers as STEM people, our interviewees generally pointed to two things: failure to display STEM interests and failure to display STEM knowledge.

When asked about their parents’ STEM interests, most interviewees described parenting as an all-consuming task that doesn’t leave room for STEM. However, this view generally did not apply to both mothers and fathers, but rather to the parent taking on the role of primary caregiver.

Similarly, most students pointed to the parent who often engaged in conversations about STEM topics as more knowledgeable, and this view also tended to exclude the primary caregiver.

Why what parents demonstrate matters

Children who grow up with the expectation of becoming a primary caregiver may associate their own caregivers’ limited displays of STEM interests and knowledge as par for the course. And because the role of primary caregiver continues to be associated with women, it’s possible for some girls to grow up believing that being a committed parent and a STEM person are incompatible roles.

Of course, STEM workers have families, and many, both men and women, are primary caregivers at home. But stereotypes are hard to break. If STEM industries want to attract more women, or if parents want their daughters to grow up to become STEM professionals, then children need to see parenthood and STEM jobs as compatible.

When parents talk to their children about their STEM-related interests and share their knowledge, children are more likely to learn that they can grow up to be both a parent and a STEM person. This approach can have an outsize effect on young women who grow up with the expectation of raising a family one day.

Creating opportunities for children to encounter female role models who are in the STEM professions is vital for attracting and recruiting women to STEM fields. Our study suggests it’s also crucial for children to see scientists and engineers as parents and caregivers with children of their own.

Plants protect themselves. They often produce chemicals that discourage animals from feeding on them. For herbivores, survival means eating enough food while avoiding dangerous toxins. This delicate balance shapes how animals forage and adapt to their environment.

The challenge is not only about survival in the present moment. It is also about long-term adaptation. Animals that fail to strike this balance risk starvation or poisoning, while successful ones pass on their strategies to future generations.

This ongoing evolutionary tug-of-war between plants and herbivores defines much of the natural world.

Utah State University ecologist Sara Weinstein believes these choices reveal much about survival. “Understanding how these animals navigate these choices is fundamental to understanding what these creatures need to survive and how species respond to changing conditions.”

Woodrats and toxic plants

Among the many plant eaters, woodrats offer a surprising case study. Native to North America, these rodents consume a wide range of plants.

“Woodrats are remarkable in their ability to eat truly awful, toxic plants,” said Weinstein. “If there are no other options, woodrats can consume plants like creosote bush, mesquite and juniper, which are full of disagreeable compounds like alkaloids and terpenes.”

Weinstein and colleagues from several universities recently published findings from an eight-year survey of woodrat populations across North America.

“Woodrats are a phenomenal model organism for understanding how wild animals make choices about what to eat,” Weinstein explains. Their habitats provide varied food choices, allowing researchers to study how animals decide among safer or riskier plants.

Analyzing the diets of woodrats

Unlike city-dwelling rats, woodrats avoid people. “Woodrats are very distant cousins of the better known, and omnivorous, New York pizza rat,” Weinstein noted. “You are unlikely to see woodrats, unless you’re in relatively undeveloped habitat.”

Despite their shy nature, woodrats are widespread across the United States. Their abundance makes them excellent research subjects, especially since multiple species often share the same environment.

“Compared to large herbivores like deer, moose or elephants, woodrats are much easier to capture and handle,” said Weinstein. “They also readily provide us with material for diet analyses, because they tend to defecate in traps.”

These droppings become data-rich samples. Weinstein noted that each sample combines about a day of food choices. This allows scientists to capture a snapshot of their diets.

Patterns in herbivore diets

Advancements in DNA metabarcoding, using next-generation sequencing, have transformed diet research.

“It’s a very powerful and accessible technique to characterize the unseen,” Weinstein said. This method has helped reveal important patterns in how herbivores eat.

Despite progress, dietary niche breadth remains poorly understood. The research shows that both specialization and generalization carry costs for herbivores.

“A longstanding notion is that if you’re highly specific in what you eat – you only eat one thing – then, if you lose access to that plant – say, it disappears because the ecosystem changes or an invasive species pushes it out – you’re going to be in trouble,” said Weinstein.

Generalists adapt more easily, shifting diets when needed. Yet the story is more complex. Most woodrat populations are generalists, but at the individual level, these generalists’ diets may not be as broad as we previously assumed, explained Weinstein.

“We tend to think of generalists as being a jack-of-all-trades, master of none. However, it looks like most generalists are more aptly described as jacks-of-all trades, master of some.”

Implications for ecosystems

Individuals often select consistent subsets of plants, helping them manage risks from toxins. These findings matter beyond woodrats.

“Ultimately, these constraints on animal diets have important implications for our understanding of food webs, species interactions and which populations are more likely to persist in changing ecosystems,” said Weinstein.

The study highlights how much we still have to learn about herbivores. By tracing dietary strategies across individuals, populations, and species, scientists gain insight into resilience and vulnerability in a changing climate.

In the end, the secret lives of woodrats remind us that even the smallest animals can unlock big lessons about survival.

The study is published in the journal Proceedings of the National Academy of Sciences.

Image Credit: Sara Weinstein

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The paper, entitled ‘Will the declining sea ice extent in the Arctic cause a reversal of net benthic-pelagic exchange directions?’ – suggests that these changes will go on to disrupt the natural movement of matter between the seabed and the water column – a key process for cycling carbon and nutrients. This movement depends on physical mixing, animal activity, and other drivers, and it can work in two directions – particles and dissolved matter moving down, or being stirred back up.

This study is part of the Changing Arctic Ocean Seafloor project (or ChAOS), which focused on the Barents Sea – a shallow shelf sea in the Arctic Ocean. Much of this work hs been carried out by Plymouth Marine Lab’s Dr Saskia Rühl.

Through in-situ sampling and experiments, Rühl and her team have examined how matter moves between the seabed and water under different ice conditions.

The study found that in the southern Barents Sea – which has more of an Atlantic influence – dissolved substances mostly move down into the seafloor while particles move up into the water. In the northern barents Sea, however – with more of an Arctic influence – the opposite happens. This makes the northern area more of what the scientists call ‘a depositional zone’ – where material settles and supports productivity near the sediment surface.

All of these findings offer insight into how a warming Arctic could reshape these vital processes in the future. As the Polar Front is pushed further North, the Northern regions are likely to become more similar to today’s Southern conditions, leading to a larger area in which particles are not deposited reliably, and seafloors are more prone to disturbances.

“Our findings highlight the need for broad, multidisciplinary monitoring of the Arctic’s changing ecosystems,” said Dr Rühl. “Understanding how particulate and dissolved fluxes respond to climate and human pressures is critical for predicting impacts on biodiversity, fisheries, and the Arctic’s role in storing carbon.

“This research provides a vital foundation for future studies and for refining ecosystem models in one of the world’s most climate-sensitive seas.”

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