New worlds in the making: Is this how our solar system was born?

Astronomers have, for the first time, directly observed the earliest physical conditions in which rocky planets begin to form around a distant, young star.

The observations offer clarity into how planetary systems like our own are born — capturing the beginning of planet formation as it unfolds around a protostar known as HOPS-315, located approximately 1,300 to 1,370 light-years away in the Orion constellation.

This celestial breakthrough was made possible through coordinated efforts by the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

By studying the gaseous and dusty disk around HOPS-315 — a sun-like star still in its infancy — researchers have conclusively identified the condensation of hot mineral grains: the initial building blocks from which planets eventually emerge.

The genesis of the solar system

HOPS-315 is a young, sun-like protostar believed to be between 100,000 and 200,000 years old, making it one of the youngest known stars to exhibit early planetary formation processes.

At this stage, a star is typically surrounded by a thick envelope of gas and dust — residual material from the collapse of the interstellar cloud that birthed it. This structure, known as a protoplanetary disk, is the very environment in which future planets form.

Using JWST’s infrared capabilities and ALMA’s powerful radio imaging, scientists managed to peer through a gap in the outer disk of HOPS-315.

This opening, coupled with the favourable tilt of the star’s disk toward Earth, allowed for a rare observational window into the hot inner region of the disk where solids begin to emerge.

In this region, researchers detected crystalline silicate minerals and silicon monoxide gas — materials that also appear in meteorites on Earth and are considered among the first solids to have condensed in the early solar system.

“We’ve captured a direct glimpse of the hot region where rocky planets like Earth are born around young protostars,” AP quoted Melissa McClure of Leiden Observatory, who led the international team.

“For the first time, we can conclusively say that the first steps of planet formation are happening right now.”

Echoes of our own solar system

One of the most significant aspects of this discovery is the detection of silicon monoxide, both in its gaseous form and in crystalline structures.

These materials condense only at extremely high temperatures and are thought to be the earliest solids to form in our own solar system over 4.5 billion years ago.

“Meteorites are fragments of asteroids that formed 4.6 billion years ago at the same time that the planets of our solar system were taking shape,” noted the research team.

These ancient space rocks contain embedded crystalline minerals rich in silicon, offering scientists a sort of fossil record of solar system formation.

Now, the observation of identical mineral signatures in the HOPS-315 disk supports the idea that these high-temperature condensation processes are not unique to our solar system.

Instead, they may be a universal characteristic of planet formation around young stars.

“This process has never been seen before in a protoplanetary disk — or anywhere outside our solar system,” Space quoted Edwin Bergin, a member of the research team from the University of Michigan.

The location of these minerals in the HOPS-315 system — at a distance from the star comparable to the main asteroid belt between Mars and Jupiter.

“We’re really seeing these minerals at the same location in this extrasolar system as where we see them in asteroids in the solar system,” added Logan Francis, a co-author from Leiden University.

How planets were formed

The findings offer compelling evidence that the solid particles forming in the disk around HOPS-315 are the earliest precursors to planetesimals — solid bodies that, through gravitational accumulation, coalesce into planets over time.

These components, composed of condensed minerals, represent the foundational seeds from which terrestrial planets like Earth and the cores of gas giants such as Jupiter originate.

“We’ve always known that the first solid parts of planets, or ‘planetesimals,’ must form further back in time, at earlier stages,” said McClure.

Although previous astronomical research has captured images of infant stars surrounded by protoplanetary disks and has detected giant, Jupiter-sized exoplanets embedded within them, these studies have not been able to observe the initial condensation phase — until now.

This new data bridges the observational gap between early disk formation and the eventual emergence of full-sized planets.

“For the first time, we have identified the earliest moment when planet formation is initiated around a star other than our sun,” McClure added.

What this means for Earth-like worlds

The discovery around HOPS-315 doesn’t just illuminate how planets are born — it provides a critical template for understanding the conditions under which systems like ours evolve.

With its young sun-like characteristics, similar disk structure, and mineral composition, HOPS-315 may be the most accurate proxy for our early solar system yet discovered.

“This is one of the things we’ve been waiting for. Astronomers have been thinking about how planetary systems form for a long period of time,” Fred Ciesla of the University of Chicago, who was not involved in the study, told AP.

“There’s a rich opportunity here.”

“We’re seeing a system that looks like what our solar system looked like when it was just beginning to form,” said Merel van ’t Hoff of Purdue University, a co-author of the study.

“This system is one of the best that we know to actually probe some of the processes that happened in our solar system.”

Van ’t Hoff added that finding more such systems would allow scientists to determine how common Earth-like planets might be across the galaxy.

“Are there Earth-like planets out there or are we like so special that we might not expect it to occur very often?” she asked.

What next in HOPS-315?

While the exact number and type of planets that might eventually form around HOPS-315 remains unknown, the current structure of its disk suggests it has the potential to produce a full planetary system, possibly similar in scale to our own solar system.

With the clear detection of solid mineral formation underway, astronomers now have the first direct evidence of the chemical and physical processes that precede planet formation.

This milestone sets the stage for a new phase of research into the origin of planetary systems, particularly the formation of rocky, potentially habitable worlds.

“This study shows that it could be a common process during the earliest stage of planet formation,” McClure avered.

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With inputs from agencies