DNA Ingredients Discovered in Ryugu Asteroid Samples

In 2020, samples from asteroid Ryugu were returned to Earth by the Japanese Hayabusa2 space probe. Analysis of these samples by Japanese researchers has revealed the presence of the five building blocks of DNA and RNA.

This discovery contributes to understanding the conditions of the early solar system and how the components for life may have arrived on Earth.

Published in Nature Astronomy, the study identified the nucleobases adenine, guanine, cytosine, thymine, and uracil. These nucleobases have also been found in samples from asteroid Bennu and in Murchison and Orgueil meteorites, indicating their widespread presence in the early solar system.

This supports the hypothesis that carbonaceous asteroids like Ryugu and Bennu delivered these components to Earth.

Ammonia, also found in the samples, may be involved in nucleobase formation.

Toshiki Koga, the study's lead author from the Japan Agency for Marine-Earth Science and Technology, stated that this discovery does not imply life on Ryugu. Instead, it suggests that primitive asteroids are capable of producing and preserving molecules crucial for the chemistry associated with the origin of life.

Bacterial Consortium Degrades Plastic Additives

German researchers have identified a bacterial consortium capable of digesting common plastic additives. Published in Frontiers in Microbiology, the study found that a group of bacterial strains—two from Pseudomonas species and one from Microbacterium—could break down various phthalate esters (PAEs).

PAEs are used to enhance plastic flexibility and are an increasing environmental pollutant with potential health impacts on humans and wildlife.

The Discovery

The research team isolated microbes from biofilm on polyurethane bioreactor tubing. This sample was cultured with diethyl phthalate (DEP) as a carbon and energy source, leading to a stable bacterial culture capable of degrading DEP. The consortium could fully degrade DEP within 24 hours at 30 degrees Celsius, provided the concentration did not exceed 888 mg/L. It also demonstrated growth using dimethyl phthalate, dipropyl phthalate, and dibutyl phthalate.

A Cooperative Process

DNA sequencing identified the bacteria in the consortium, revealing that individual strains could not degrade PAEs independently. This indicates a cooperative process, or cross-feeding, is involved in chemical breakdown.

This bacterial consortium offers a potential method for degrading PAEs in contaminated environments, accelerating the breakdown of PAE-containing plastics, and treating industrial plastic waste.

Hubble Telescope Observes Comet Fragmentation

The Hubble Space Telescope has captured images showing the breakup of Comet C/2025 K1 (ATLAS) in November as it exited the solar system. A research team, having redirected their observation target, documented Comet K1 shortly after its fragmentation began.

Hubble recorded three 20-second images between November 8 and November 10, 2025. The initial image is estimated to have been taken approximately eight days after the fragmentation commenced. During this period, a smaller piece of the comet also started to break apart.

John Noonan, a research professor at Auburn University, stated that this observation marked a rare instance of Hubble capturing a comet's fragmentation just days after it began, rather than weeks or months later.

This observation marked a rare instance of Hubble capturing a comet's fragmentation just days after it began, rather than weeks or months later.