DNA, Greenhouse Gases, and Rock Salt Alternatives

DNA, explained

Deoxyribonucleic acid, or DNA, is the molecule that encodes the genetic information of all known living things. Tightly packed into the nucleus of nearly all cells (watch visualization), DNA takes the shape of a double helix—a twisted ladder—with rails made up of stacked sugar-phosphate groups connected by rungs made up of four types of nitrogen-containing bases in pairs (see diagram). The order of these bases mimics the letters of an alphabet, spelling out genes that carry the instructions for an organism's traits.

DNA was initially called "nuclein" after its discovery in the nuclei of white blood cells in 1869. Although DNA's bases were discovered by the late 1800s, scientists were skeptical that it was a hereditary molecule and viewed proteins, which were made of 20 different building blocks, as more likely to code for the wide variety of observed life (explore historical timeline). However, by 1952, experiments had shown that bacterial traits changed when they took up DNA rather than proteins, overturning the prevailing wisdom (watch explainer). The following year, DNA's structure was identified, and subsequent observations of how proteins responsible for cellular function are encoded in DNA led to modern genetics (watch how DNA is translated into proteins).

Advancements in DNA sequencing and editing have enabled breakthrough technologies, including the testing and diagnosis of genetic disorders, disaster victim and forensic identification, genetically engineered crops and microbes for medicines (e.g., insulin production), the detection and tracking of variant pathogens (e.g., influenza), and various gene therapies.

Learn even more by exploring all our findings on DNA here.

Here's a sample of what we found ... 

> The average cell's DNA is damaged thousands of times daily. (Watch)

> Some cells destroy their own DNA to be able to complete specific functions. (Read)

> How do scientists actually read DNA? (Watch)

> The molecule that may have allowed life to exist before DNA. (Watch)

Greenhouse gases, 101

Greenhouse gases are molecules that absorb thermal radiation emitted by a planet and emit it in all directions, including back to the planet's surface. Unlike the various types of light that a planet can reflect, this emitted planetary radiation is primarily a smaller subset of the electromagnetic spectrum (e.g., infrared). By acting as a blanket that prevents some of this energy from escaping to space, a planet warms in a phenomenon called the greenhouse effect (see visualization).

In the early 1800s, as scientists began developing the field of thermodynamics to improve the efficiency of steam engines, an analysis of Earth revealed it to be much warmer than expected. Sunlight alone was shown to be insufficient, and the atmosphere was hypothesized to act as an insulator. By mid-century, experiments showed that some atmospheric gases, including water vapor and carbon dioxide, could absorb and emit some infrared radiation—the kind emitted by Earth's surface—significantly altering the planet's climate (watch demonstration).

Despite greenhouse gases accounting for less than 0.04% of the Earth's atmosphere, average surface temperatures would be about 33 degrees Celsius (59 degrees Fahrenheit) lower without them. However, atmospheric carbon dioxide concentrations have increased by over 50% since before the Industrial Revolution—primarily driven by the burning of fossil fuels—causing a rise in average surface temperatures during the same period (view emissions data).

Learn even more by exploring all our findings on greenhouse gases here.

Here's a sample of what we found ...

> Greenhouse gas concentrations are measured by their unique spectral fingerprints. (View)

> Feeding cattle seaweed reduced their methane emissions by nearly 40%. (Read)

> What makes certain molecules greenhouse gases? (Watch)

> The techniques that can capture and store greenhouse gases. (Watch)

What is the James Webb Space Telescope?

The James Webb Space Telescope is a $10B telescope launched by NASA in 2021 that captures infrared light from across the universe. As of 2025, it is the largest space telescope, able to detect light from the earliest observable moments of the universe about 13.5 billion years ago.

Webb's observations are possible thanks to its distinctive 6.5-meter (21-foot) mirror, composed of 18 hexagonal, gold-plated beryllium mirrors arranged in a honeycomb (watch explainer). To keep the mirrors cool enough to retain sensitivity across the long-wavelength visible to mid-infrared range, a tennis court-sized sunshield (see visualization) keeps Webb's instruments permanently in shadow as the spacecraft orbits the sun. In this range, Webb can see through visible light-blocking cosmic dust.

Since it began operations in the summer of 2022, Webb's accomplishments include observing the atmospheres of exoplanets in search of life, viewing the universe's first stars and galaxies to understand our origins, and collecting data used to refine calculations of the rate of expansion of the cosmos (see discovery timeline).

Learn even more by exploring all our findings on the James Webb Space Telescope here.

Here's a sample of what we found ... 

> AI fixed blurriness in the James Webb Space Telescope's infrared imaging. (Read)

> Webb orbits in a special location without the need for constant course corrections. (Watch)

> Fly through a visualization of the "Pillars of Creation," made using Webb data. (Watch)

> View a gallery of images taken by the James Webb Space Telescope. (View)

Science Spotlight

Like all great scientists, we love spending time researching the latest scientific breakthroughs, tech releases, engaging explainers, and the connections between science and society that are making headlines. Here's what we found this week.

> Visualize the downsizing of US science in 2025

Nature | Staff. In an effort to reshape and shift priorities within the federal scientific workforce, which shrank by about 25,000 scientists and personnel, more than 7,800 research grants were terminated or frozen last year. Changes disproportionately impacted projects involving misinformation, vaccine hesitancy, infectious diseases, and research on people from underrepresented ethnic and gender groups. (Read)

> The United Nations reports the world has entered a period of 'water bankruptcy'

Smithsonian Magazine | Sara Hashemi. The effects of climate change, land degradation, deforestation, pollution, and water overuse have created regions where groundwater and other reservoirs have emptied. Water demands surpass river and snowmelt supply at these locations, preventing long-term reservoir recovery. (Read)

> Discovering how to develop carbon dioxide-based energetic materials

Lawrence Livermore National Laboratory | Ashley Piccone. Researchers combined dynamics simulations with machine learning models to uncover a recipe for making stable, energetic materials under high-pressure conditions. Experiments can now test compressing carbon monoxide and oxygen to fabricate new propellants. (Read)

> Air pollution reduction policy may have worsened coral bleaching

University of Melbourne | Staff. In 2020, the International Maritime Organization worked to reduce sulfur dioxide and sulfur particulate matter produced from ships when burning fuel. The efforts inadvertently stressed the Great Barrier Reef by reducing the amount of sun-blocking aerosols, increasing ocean heating. (Read)

> Solar flares originate from 'snowballing' magnetic disturbances

European Space Agency | Staff. Just as avalanches start with the movement of a small quantity of snow, the Solar Orbiter spacecraft discovered that a solar flare is triggered by initially weak disturbances that rapidly turn violent. This process creates streams of raining plasma that continue to fall even after the flare subsides. (Read)

Best of the Week

We curate hundreds of resources into 1440 Topics each week. Here are some of our favorites from the world of science and technology.

Read:

> Why satellites pose an increasing risk to space observations.

> Pet- and yard-friendly alternatives for clearing ice and snow without rock salt.
> Estimating the total number of species on Earth.
> How data center energy demands are driving a fracking boom.

> How much energy do our brains need to think?

> Exploring the limits of digital cadavers in medical education.

Listen:

> Tips on improving the flavor and texture of meals using molecular gastronomy.

> How are personal relationships being changed by AI companions?
> Are humans currently driving Earth's sixth mass extinction event?

Watch:

> After the Grammy Awards, we wondered: how does fame affect the brain?

Thank you to our readers for inspiring us with their questions! Curious about something in science and technology? Tell us here.

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