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Astronomers have made significant strides in understanding how planets like the ones in our solar system form by detecting planet-forming “pebbles” around two young stars

These tiny rocky particles were discovered orbiting DG Tau and HL Tau, two stars located approximately 450 light-years from Earth, providing a rare opportunity to understand the earliest stages of planetary formation.

Planetary seeds in action

The new observations show large reservoirs of solid material, or pebbles, in the wide discs of dust and gas that surround these young stars. These discs, known as protoplanetary discs, are the birthplaces of planets.

Over time, these tiny pebbles clump together, forming larger and larger bodies that eventually create planets like Earth, Jupiter, and other worlds in our solar system.

The importance of this discovery lies in the fact that these pebbles have been found at distances similar to Neptune’s orbit, which suggests that the entire planetary system could be forming right now in these distant stellar nurseries.

Understanding the missing link in planet formation

Although astronomers have always known that dusty discs often surround young stars and have discovered thousands of fully formed planets in other star systems, the in-between stage has always been much harder to observe.

Astronomers struggle with determining the size of the particles; smaller grains are easily visible using optical and infrared telescopes, but as the grains grow and clump into larger pebbles, their surface area decreases, making them harder to detect.

To solve this mystery, astronomers used MERLIN, which is a unique array of seven radio telescopes spread across the UK. This robust network is capable of detecting the radio signals emitted by centimetre-sized pebbles, which shine brightest at similar wavelengths.

A breakthrough using e-MERLIN

Using e-MERLIN, researchers captured a striking image of DG Tau’s disc showing centimetre-sized pebbles already present at long distances from the central star. A similar pattern of rocky seeds has also been observed around HL Tau. These findings suggest that planet formation begins much earlier and farther out than previously understood.

The project behind this breakthrough is known as PEBBLeS (Planet Earth Building-Blocks – a Legacy eMERLIN Survey), a large-scale effort to map and study the building blocks of future planetary systems.

The success of e-MERLIN will soon enable more powerful observations. The upcoming Square Kilometre Array (SKA) telescopes, currently under development in South Africa and Australia, will increase astronomers’ ability to study protoplanetary discs. With greater sensitivity and resolution, the SKA will be able to observe hundreds of developing planetary systems across our galaxy.

When science operations with the SKA-Mid telescope begin in 2031, researchers will be ready to build on the work started with e-MERLIN.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors.

Source: Perspectives of Earth and Space Scientists

Our modern society is increasingly reliant on multiple technologies that are vulnerable to the adverse effects of space weather. This necessitates effective public communication and awareness of various space weather phenomena as well as increased public engagement and preparedness for risk mitigation.

Chabanski et al. [2025] advocate for the development and implementation of a standardized naming convention of geomagnetic storms, along the lines of existing naming conventions in meteorology, astronomy, and geography.

The authors surveyed the top 50 geomagnetic storms over the past 47 years (since 1978), of which only five had names assigned by the scientific community. Drawing on lessons learned in other scientific disciplines, they propose the possible formation of an international working team comprised of International Space Weather Coordination Forum participants. This international team would implement a theoretical framework and a unified international standard for defining the criteria, protocols, and procedures for naming and cataloguing geomagnetic storms based on their minimum Disturbance Storm Time (Dst) indices and their solar origins.

This proposed initiative is about not only assigning names to geomagnetic storms but also empowering the public with the knowledge necessary to navigate the challenges of the 21st-century space environment.

Citation: Chabanski, S., de Montety, F., Lilensten, J., Poedts, S., & Spogli, L. (2025). The power of a name: Toward a unified approach to naming space weather events. Perspectives of Earth and Space Scientists, 6, e2025CN000285. https://doi.org/10.1029/2025CN000285

—Andrew Yau, Editor, Perspectives of Earth and Space Scientists

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Related

On July 9, 2025, Earth spun a little faster than usual, enough to make the day about 1.3 to 1.6 milliseconds shorter than the standard 24 hours.

That may not sound like much, but it was the shortest day since modern records began.

An astronaut on the International Space Station has captured a rare kind of lightning called a sprite while traveling 250 miles above the Texas–Mexico border. Referred to as “space lightning” and compared to a jellyfish in shape, the rare weather phenomenon was captured on camera by NASA astronaut Nichole Ayers.

The rare image was taken on July 3 by pilot Nichole Ayers, who launched to the ISS on March 14, 2025, as part of the SpaceX Crew-10 mission. It shows an ethereal crimson jellyfish-like flash shooting from the tops of clouds and into space. It’s known as a “red sprite,” but also as a transient luminous event, lightning in Earth’s upper atmosphere. According to NASA, these colorful, bright, faster-than-lightning flashes are generated above the clouds by thunderstorms.

Ayers’ Explanation Of The ‘Sprite’

“Just. Wow. As we went over Mexico and the U.S. this morning, I caught this sprite,” wrote Ayers on X/Twitter. “Sprites are TLEs or Transient Luminous Events that happen above the clouds and are triggered by intense electrical activity in the thunderstorms below. We have a great view above the clouds, so scientists can use these types of pictures to better understand the formation, characteristics, and relationship of TLEs to thunderstorms.” In a later message, she stated that it was a gigantic jet, another type of TLE. “So cool to learn as we go up here,” she wrote.

The image also shows the glow of Dallas, Austin, San Antonio and Houston to the northeast, with Torreón, Mexico, to the southwest. “Our hearts go out to the families affected by the flooding in the Texas Hill Country this weekend,” added Ayers.

How The Image Was Taken

The ISS is the best observation point humankind has for monitoring Earth at night but photographing lightning takes a huge amount of patience and trial and error. Astronauts on the ISS take photos from the Cupola (Italian for dome), an observatory module that has seven windows and allows photography of Earth. Ayers took the shot using a Nikon Z9 and a 50mm lens as part of a time-lapse project during which she took multiple images. “To record a photo like this takes skill to set up the camera but more than that, the knowledge of what lightning systems are likely to create sprites and the willingness to take 2000-5000 images where only one will record a sprite,” wrote NASA astronaut and astrophotographer Don Pettit on X/Twitter, who arrived back from the ISS on April 19. “Kudos to Nicole for her imagery efforts!”

The ISS And The ‘Great North American Eclipse’

Perhaps the most widely seen images taken from the ISS were those of the total solar eclipse on April 8, 2024. NASA flight engineers Matthew Dominick and Jeanette Epps captured unique views of the moon’s shadow over part of Maine, U.S. and Quebec and New Brunswick, Canada. For the shots, NASA carefully adjusted the altitude of the orbiting laboratory for months, leading up to the final total solar eclipse in the contiguous U.S. until 2044.

Wishing you clear skies and wide eyes.