Jul 22, 2021

Axios Science

Welcome back to Axios Science. This week's newsletter — about Mars' interior, AI answers to protein-folding problems and more — is 1,711 words, a 6½-minute read.

1 big thing: Deep inside Mars

Illustration: Megan Robinson/Axios

Seismic action on Mars is revealing new details about the inner structure of the Red Planet.

Why it matters: Mars' interior holds the key to understanding how the planet and its atmosphere formed — and provides clues about how other rocky planets, like Earth, become habitable.

  • "Mars is a second laboratory in planetary formation," says Bruce Banerdt, principal investigator of NASA's InSight mission to study the interior of Mars.

Driving the news: A trio of new studies published today in the journal Science reports the first direct measurements of the interior of Mars and, for that matter, another planet.

  • The InSight mission measures seismic waves from fractures in Mars' surface thought to be caused by heat escaping the planet's still-cooling core.
  • The low-frequency waves created by these Marsquakes are picked up directly by the seismometer or after they travel through the planet, bouncing off the core and surface.

What they found: The teams of researchers measured the strength and speed of the reflected waves from 8–11 Marsquakes to determine key aspects of the size and composition of Mars' interior.

Core: They estimate Mars' core has a radius of about 1,140 miles, which is 100 miles larger than theories predicted and about half the radius of the planet.

  • That means the density of the mostly iron and nickel core is less than previously thought and the center of Mars likely includes other elements, like sulfur, carbon, hydrogen and oxygen.
  • The scientists also confirmed the core is still liquid, likely because of the other elements dissolved in it.
  • The intrigue: The estimated size of the core implies it is 15–18% sulfur, about twice what can be accounted for in existing models, according to Banerdt. "We don't know how to get that much sulfur," he says, adding it may have to do with the density of the mantle.

Mantle: Mars' middle layer, which insulates the core, is relatively thin, which may explain why the planet cooled more quickly than Earth and lost its protective magnetic field.

  • On top of the mantle, there is a thick lithosphere — the rigid outer shell that makes up the crust and upper mantle — about 310 miles below the surface, the researchers report. The thickness of the lithosphere might explain why plate tectonics — or volcanic activity — isn't seen on the Red Planet today.
  • The mantle, which the data suggest consists of just one rocky layer compared to Earth's two, makes up the bulk of the planet. "We have to understand the mantle to understand the planet," Banerdt says.

Crust: The outermost layer of the planet is estimated to be between 15 and 45 miles thick — not as thick and dense as researchers earlier predicted from satellite data — and made up of two or three layers.

  • The researchers also found the crust is 13–21 times more enriched in radioactive elements that produce heat, which hints at its composition and how it formed through early volcanic activity.

What's next: InSight received a mission extension until at least the end of 2022.

  • In that time, Banerdt says they'll focus on detecting more quakes, collecting data to understand seasonal and annual variations in weather, and looking at whether some types of seismic events vary between seasons on the planet.

Go deeper.

2. AI solves some of biology's longtime mysteries

Illustration: Aïda Amer/Axios

AI is speeding up the discovery of the structure of proteins that drive biological processes across organisms, Axios' Eileen Drage O'Reilly writes.

Why it matters: If researchers can predict what shape a protein will take, they can better understand how it works — and potentially target medicines for proteins that cause disease or create antibiotics that can disable proteins in resistant bacteria.

The big picture: Determining the structure of proteins is typically done through painstaking experiments involving crystallizing proteins and analyzing them with X-rays. That's yielded the shapes of a small fraction of proteins in humans.

  • But new machine-learning systems like AlphaFold and RoseTTAFold are making a "once in a generation" advance and have been able to speed up the discovery process greatly.
  • "If you really want to understand how biology works at the molecular level — and that is really where it works, with little machines interacting with each other — you need to know the shape of the protein molecules," said John Moult, a structural biologist at the University of Maryland, Shady Grove.

The latest: Google DeepMind's AlphaFold2 system is able to issue a “good prediction" of protein structures about 95% of the time, scientists said at a joint press conference announcing DeepMind and the European Molecular Biology Laboratory's collaboration.

  • Using AlphaFold2, scientists were able to generate 3D models of 350,000 proteins, 36% of which have a "high confidence," they said.

Context: The AlphaFold2 findings follow last week's announcement that the University of Washington created a neural network, RoseTTAFold, to determine protein structures and it published several openly via GitHub.

What's next: "This is just the first clear demonstration of the power of AI in biology," Moult said.

  • "Our understanding of protein structures and associated biology will take a big leap forward as people build on these resources," he said.
3. Catch up quick on COVID-19
Expand chart
Data: CSSE Johns Hopkins University; Note: Rhode Island and Iowa data is from CDC and from July 12-July 29; Map: Axios Visuals

"Coronavirus infections are rising dramatically all over the U.S. as the highly contagious Delta variant spreads," Axios' Sam Baker writes.

COVID-19 drove life expectancy in the U.S. down by 1.5 years in 2020, according to new CDC data. It is the biggest decline since World War II.

The coronavirus cuts structures on the surface of cells, which may help it invade the lungs, Erin Garcia de Jesús reports for Science News.

"Breakthrough" infections of COVID-19 are rare and the vaccines are working, top health experts said this week, per the AP's Lauran Neergaard.

4. What science is missing

Photo illustration: Sarah Grillo/Axios. Photos: NASA/Donaldson Collection, Bertram/Three Lions via Getty Images

Chanda Prescod-Weinstein, a theoretical physicist at the University of New Hampshire, is one of about 100 Black American women physicists, but she nearly left the field in her first semester in college. She isn't the only scientist of color who thought of giving up before her career began.

Why it matters: That marginalization affects not only those who pursue science as a career but the problems scientists address, Axios' Miriam Kramer and I write in Axios' latest Hard Truths report.

The big picture: Latino and Black students leave science degree programs at higher rates than white students and receive fewer Ph.D.s.

  • "I didn’t understand that this was entirely a resource question — that they [white classmates] had more opportunities than I had," Prescod-Weinstein, who recently wrote a book about her journey, told Axios. "I just thought I wasn’t good at solving problems."
  • People of color are underrepresented in university faculties and, in some fields, they are funded at rates lower than their white colleagues.

Science limits itself by excluding these groups.

  • For example, Indigenous knowledge about the history of repeated earthquakes predates scientific records in some places and can be used to reconstruct how often events occur, says geologist Rachel Bernard of Amherst College.

What's happening: Some institutions are putting resources behind hiring experts to evaluate their hiring initiatives.

  • The U.S. Senate has passed a bill that would authorize the National Science Foundation, which administers about a quarter of the total federal funding for basic science at U.S. universities and colleges, to lead on bringing more diversity to science.
  • A program founded by Vashan Wright of Woods Hole Oceanographic Institution, called Unlearning Racism in Geoscience (URGE), aims to educate geoscientists about racism and develop policies to fight it in a field that has been historically among the least diverse in science.

Between the lines: Improving representation alone won't solve racial injustices in science.

  • "There are cultural norms that need to change for everybody," says C. Brandon Ogbunu, an assistant professor at Yale University who studies disease evolution and ecology.
  • "Discrimination lurks in the margins of fields." Examples include not citing a paper because a name isn't recognized, subjective decisions about who is an expert, and professional networks whose social norms aren't inclusive, he says.

Read the entire report.

5. Worthy of your time

Illustration: Sarah Grillo/Axios

Concerns emerge over climate science blind spot (Andrew Freedman — Axios)

The world’s first genetically engineered marsupials give a fresh window into human biology (Megan Molteni — STAT)

Chunk of an ancient supercontinent discovered under New Zealand (Maya Wei-Haas — National Geographic)

A century of astronomy revealed Earth’s place in the universe (Lisa Grossman — Science News)

6. Something wondrous

A sulphur-crested cockatoo opening a lid to a trash can. Credit: Barbara Klump/Max Planck Institute of Animal Behavior

Cockatoos appear to learn how to open a garbage bin from each other, according to a new study.

The big picture: Social learning is a key driver of culture — documented in whales, primates and, of course, humans — that researchers are trying to better understand.

Sulphur-crested cockatoos (Cacatua galerita) can be spotted in the suburbs of Sydney, Australia, using their beaks and feet in different ways to lift garbage bin lids before feasting on their finds.

  • "I find it amazing how dexterous they are," says Barbara Klump of the Max Planck Institute of Animal Behavior, adding that it is a sequence of five different steps.

What they found: The researchers used two different datasets to determine whether the bin-opening techniques were socially learned or individuals figured it out by themselves.

  1. In an online survey, they asked residents to report whether they'd seen cockatoos doing this and when. In 2018, residents from three areas said they spotted it. By the end of 2019, people in 44 areas said they've seen the birds opening bins, indicating the behavior spread fast.
  2. They recorded and analyzed the behavior of about 500 cockatoos in three suburbs. They found only about 10% of the birds could successfully open the bins, and they were mostly males.

The intrigue: They found the birds' techniques were more similar the closer they were geographically to each other.

  • They also observed an innovative bird in northern Sydney that changed the technique, which nearby birds then learned.
  • "It shows we don’t just have this animal culture of bin-opening but also local subcultures of opening," Klump says.

Yes, but: It's too soon to say the birds have culture, cognitive scientist Claudio Tennie of the University of Tübingen told Science's Cathleen O'Grady.

  • That would require finding a bin-opening sequence that is locally unique.

What's next: Birds aren't the only animals adapting: People have started to protect their bins, and the researchers want to look at whether the birds are changing their behavior as a result.