Scientists have found that twisting structures in DNA long mistaken for knots are actually something else entirely.

Inside cells, DNA gets twisted, copied, and pulled apart. The twists can influence how genes function, affecting which are switched on and when. Studying how DNA responds to stress can help scientists better understand how genes are controlled, how the molecule is organized, and how problems with these processes might contribute to disease.

For years, researchers have been using nanopores — tiny holes just wide enough for a single DNA strand to slip through — to read DNA sequences quickly and inexpensively. These systems work by measuring the electrical current flowing through the nanopore. When a DNA molecule passes through, it disrupts that current in a distinct way that corresponds with each of the four "letters" that make up DNA's code: A, T, C and G.

Unexpected slowdowns or spikes in this signal were often interpreted as knots in DNA. But now, a new study published Aug. 12 in the journal Physics Review X finds that these signal changes can also signify plectonemes, which are natural coils that form when DNA twists under stress.

Scientists have developed a better model to understand "steam worlds," which are planets smaller than Neptune and larger than Earth that are too hot to have liquid water at their surface and thus have atmospheres filled with water vapor. Though steam worlds are unlikely to harbor life, modeling them more precisely could help scientists better comprehend ocean planets better, which in turn would aid in directing our search for life beyond the solar system.

A political scientist came across the Civic Online Reasoning curriculum, developed by the research group I used to lead at Stanford University. The curriculum, which is freely available to anyone, teaches a set of strategies based on how professional fact-checkers evaluate online information.

In fall 2021, he reached out with a question: Could aspects of the curriculum be incorporated into American Government 1101 without turning the whole course on its head?

My team and I thought so.

Did you know the Moon quakes? Apollo seismometers recorded thousands of vibrations. Now, scientists are using Apollo samples and data from NASA’s Lunar Reconnaissance Orbiter to forecast moonquakes and help keep future Artemis astronauts safe. https://t.co/uUKkMhtCsX

In a new experiment, scientists used virtual reality to show that the brain can sense virtual infection to trigger the body’s immune system, before the first microbe ever makes contact.

The immune system detects and responds to the presence of a pathogen to eliminate or counteract its toxic effects. However, the delay in this process might weaken its efficacy. A recent report in Nature Neuroscience shows how the neural system primes the immune response in anticipation of a potential infectious threat, even without actual pathogen.

Gordon Cooper joked with mission control on Day 4 of their Gemini V flight 60 years ago: "We just finished off our sausage and eggs that Pete cooked this morning, and he's making the coffee now."

Cooper and crewmate Pete Conrad had little appetite on their 8-day mission and did not eat much of the cold, dehydrated, prepackaged food provided. They each lost more than 7 lbs (3.3 kg) over their spaceflight.

Read more about early space food: https://t.co/8Y38pudbjD

Tiny particles floating in our air.

This visualization shows how tiny particles called aerosols move through Earth's atmosphere from August 1 to September 14, 2024, using NASA's Goddard Earth Observing System (GEOS) model. These particles, which include sea salt, dust, smoke, and sulfates, can travel thousands of miles and affect air quality and visibility far from their original sources.

By tracking these movements, NASA helps communities prepare for changes in air quality and visibility while advancing our understanding of Earth's complex atmospheric system.

Watch the complete video: https://t.co/YxA4A6hMp0

Exp 73 tested a special leg cuff to protect crews from space-caused head and eye pressure while also unpacking the SpaceX #Dragon and readying it for a station reboost. https://www.nasa.gov/blogs/spacestation/2025/08/27/head-and-eye-health-dragon-reboost-preps-and-emergency-drill-fill-crew-day/

For more than three decades, satellites have tracked global sea-level change, and a recent analysis shows that projections made in the mid-1990s were strikingly accurate. The findings, published in Earth’s Future, an open-access journal of the American Geophysical Union, come from two researchers at Tulane University.

“The ultimate test of climate projections is to compare them with what has played out since they were made, but this requires patience – it takes decades of observations,” said lead author Torbjörn Törnqvist, Vokes Geology Professor in the Department of Earth and Environmental Sciences.

“We were quite amazed how good those early projections were, especially when you think about how crude the models were back then, compared to what is available now,” Törnqvist said. “For anyone who questions the role of humans in changing our climate, here is some of the best proof that we have understood for decades what is really happening, and that we can make credible projections.”

Sometimes scientists use enhanced-color images to reveal subtle variations on the surface of Mars. This view from our Mars Odyssey orbiter highlights details in clouds hovering over canyons in the Margaritifer Terra region in December. More from Odyssey: https://t.co/EouBe2Uve9

The ambitious mission to retrieve samples from asteroid Bennu and return them to Earth is paying off.

Just as scientists had hoped, the asteroid is revealing details about the early days in our Solar System. More than just a simple space rock, Bennu contains not only material from the Solar System, but material from beyond our system.