JWST Captures Earliest Steps of Planet Formation Around HOPS 315 in Orion

Overview

In this episode, the James Webb Space Telescope discovers HOPS 315, a newborn star in the Orion Nebula, still enveloped in gas and dust as its protoplanetary disc forms. Webb's infrared spectra detect warm silicon monoxide gas and tiny silica crystals, the first clear sign of gas condensing into solids during planet formation. ALMA follows up with millimeter observations to map the colder disc regions, linking the formation zone to the asteroid-belt region our solar system may later host. The video explains the condensation sequence, implications for how many planets might arise, and what this means for our understanding of planet formation across the universe. This discovery could rewrite timelines of planet formation and provide a direct glimpse into processes that shape every planetary system.

Introduction and context

The video discusses a breakthrough observation by the James Webb Space Telescope of HOPS 315, a very young star in the Orion Nebula, less than 150,000 years old and still growing in a cloud of dust and gas. The focus is on the very early phase of planet formation as a nascent disc emerges around this stellar embryo.

Discovery details and evidence

Webb's infrared spectrum reveals warm silicon monoxide gas and tiny silica crystals near the young star, indicating the moment gas begins to crystallize into solids. This condensation sequence is inferred from the chemistry of primordial materials and by studying meteorites, marking the earliest moment of planet formation seen in real time.

Role of ALMA and disc structure

To complement Webb, ALMA targets the colder, outer regions of the disc, tracing dust and gas at millimeter wavelengths. The combined data connect the inner warm part of the disc with a broader formation zone, roughly in the same region where our own asteroid belt would later form, suggesting a common early pathway for planet formation across systems.

Implications for planet formation theory

The detection of calcium aluminum inclusions and crystalline silicates around HOPS 315 implies that the inner disc could begin building planets earlier than previously thought. This supports the idea that planetesimal growth may start while the star is still forming, rather than waiting for a calm debris disc to emerge.

What this means for our solar system

If HOPS 315 follows a similar condensation sequence to the early solar system, the timing and location of ice lines, or snow lines, and the emergence of rocky planets versus gas giants could be established much earlier. The potential for an asteroid belt to arise near the snow line remains a compelling question for this young system.

Open questions and future work

Researchers plan to survey more very young stars to determine how widespread these early formation hallmarks are. Questions remain about how many planets form around such stars, whether they migrate, and how quickly discs evolve in the earliest stages of stellar life.

Conclusion

HOPS 315 offers a portal to our past, providing a rare glimpse into the very first steps of planet formation and a testing ground for models of how planetary systems emerge throughout the universe.