Brain growth slowed down about 300,000 years ago due to energetic and climate pressures, according to a study published in Brain & Cognition.

One of the puzzles of human evolution is why Homo sapiens is the only surviving species within the Homo lineage. Larger brains have often been seen as a key advantage, enabling fire use, tool-making, and symbolic communication. However, big brains also come at a cost—they consume around 20% of our resting energy and produce considerable heat, which can be a liability in warmer climates.

Study author Jeffrey M. Stibel examined this evolutionary trade-off. Earlier Homo species experienced strong selection for larger brains, which likely helped them navigate shifting environments and complex social worlds. But fossil evidence suggests that in the past 100,000 years, brain size began to plateau or even shrink, raising the possibility that survival depended not just on biology but also on cultural innovations.

The Dragonfly mission is flying through milestones! Recent thermal and environmental testing shows how the rotorcraft will survive and navigate Titan’s skies. This bold mission will explore one of our solar system’s most intriguing worlds. https://t.co/ctPlSEzMyS

The greatest challenge facing astrobiologists is that there is only one planet known to us that has life. Of all the bodies of the Solar System, only Earth has a dense atmosphere, liquid water on its surface, and the organic chemistry that supports life.

However, these conditions did not exist billions of years ago when Earth was still young. While the nebula from which the planets formed was rich in volatile elements, the high temperatures in the inner Solar System largely prevented them from condensing, leaving them mostly in a gaseous state.

As a result, these elements were not incorporated into the solid rocky materials from which the inner planets formed. Only celestial bodies that formed farther from the Sun retained the substances essential to life, which raises questions about how and when they were introduced to Earth.

In a new study, researchers from the University of Bern showed for the first time how the chemical composition of primordial Earth was complete three million years after it formed (ca. 4.5 billion years ago).

Their results imply that the ingredients for life (water, carbon compounds, sulfur, etc.) were introduced later, likely by an impact.

Starting next month, four volunteers will spend a year inside a 3D-printed habitat at NASA Johnson to help us prepare for future missions to Mars.

Meet the members of our new CHAPEA crew: https://t.co/BMnXQaWq1O

The ocean is filled with life, yet much of it remains hidden unless observed at very close range. Water acts like a natural veil, bending and scattering light while also dimming it as it moves through the dense medium and reflects off countless suspended particles. Because of this, accurately capturing the true colors of underwater objects is extremely difficult without close-up imaging.

Researchers at MIT and the Woods Hole Oceanographic Institution (WHOI) have created an image-analysis system that removes many of the ocean’s optical distortions. The tool produces visuals of underwater scenes that appear as though the water has been removed, restoring their natural colors. To achieve this, the team combined the color-correction tool with a computational model that transforms images into a three-dimensional underwater “world” that can be explored virtually.

The team named the tool “SeaSplat,” drawing inspiration from both its underwater focus and the technique of 3D Gaussian splatting (3DGS). This method stitches multiple images together to form a complete 3D representation of a scene, which can then be examined in detail from any viewpoint.

“With SeaSplat, it can model explicitly what the water is doing, and as a result, it can in some ways remove the water, and produces better 3D models of an underwater scene,” says MIT graduate student Daniel Yang.

On Wednesday, Sept. 10 at 11am EDT, NASA will host a media teleconference with Acting NASA Administrator Sean Duffy and experts from the Mars Perseverance mission to discuss the analysis of a rock sampled by the rover.

Set a reminder:
https://www.youtube.com/live/-StZggK4hhA

🌙 A blood moon from the edge of the world 🇦🇶
🌒 A few nights ago, around 85% of Earth could see a total lunar eclipse - including the crew of Concordia station in Antarctica, a place more remote than the Space Station.
📸: esa /IPEV/PNRA/DC21-J. Lacrampe, sivrupanin

A landmark federally funded clinical trial has provided the first real evidence that doctors can pinpoint breast cancer survivors at higher risk of relapse by detecting dormant cancer cells, and that these hidden cells can be successfully treated using already available drugs. The work, led by researchers at the Abramson Cancer Center of the University of Pennsylvania and Penn’s Perelman School of Medicine, appears in the journal Nature Medicine.

Although survival rates for breast cancer continue to improve thanks to better screening and therapies, the disease remains incurable once it comes back after initial treatment. About 30 percent of women and men experience a relapse, leaving them dependent on ongoing treatment that cannot completely remove the cancer. Some forms, such as triple negative and HER2+, often reappear within a few years, while ER+ cases can resurface even decades later. Until now, doctors had no way to identify which survivors carried dormant cells that fuel recurrence or to step in with a therapy that could prevent it.

One of the first parts of the brain affected by Alzheimer’s disease is the entorhinal cortex — a region that plays a big role in memory, spatial navigation, and the brain’s internal mapping system.

With support from the Commonwealth of Virginia’s Alzheimer’s and Related Diseases Research Award Fund (ARDRAF), Fralin Biomedical Research Institute at VTC scientists Sharon Swanger and Shannon Farris are working to understand why this area is especially vulnerable.

A large study of more than 5 million women over 30 years has suggested that CT scans before conception could increase the risk of pregnancy loss and congenital anomalies.

As concerning as the results seem, there are a lot of caveats to consider.

This observational study was conducted in Ontario, Canada, between 1992 and 2023, involving 5,142,339 pregnancies that resulted in 3,451,968 live births. Generally, rates of spontaneous pregnancy loss and congenital anomalies were found to increase in patients who had more CT scans prior to conception.

Compared to patients who had no CT scans, the risk of pregnancy loss increased by 8 percent for those who had 1 scan, 14 percent for 2 scans, and 19 percent for 3 or more scans. The risk of congenital anomalies increased by 6 percent for 1 scan, 11 percent for 2 scans, and 15 percent for 3 or more scans.

That sounds alarming, but extra context is important.

First, the increase itself is rather small: If, for example, your baseline risk is 10 percent, and it increases by 19 percent after 3 scans, the new risk is 11.9 percent.

Secondly, the study shows a correlation but not necessarily causation, and other factors are almost certainly at play. For instance, people don't tend to require CT scans for trivial reasons – the reason they're getting checked out could be a bigger driver of problems than the scan itself.