Webb eyes a pair of planet-forming disks in Taurus and Ophiuchus

This month’s NASA/ESA/CSA James Webb Space Telescope Picture of the Month delivers something unusual: not one, but two protoplanetary disks captured in a single visual release, each orbiting a newly born star and each potentially harboring the seeds of future planets. The two objects — Tau 042021 in the constellation Taurus, located roughly 450 light-years from Earth, and Oph 163131 in Ophiuchus at approximately 480 light-years — share a striking geometric coincidence: as seen from our vantage point, both disks are oriented edge-on, with the flat plane of the disk facing directly toward us.

This orientation is scientifically valuable precisely because it hides the blinding glare of the central star behind the disk itself, allowing Webb’s instruments to illuminate the fine dust that has risen above and below the disk plane, lit by reflected starlight and glowing in colors that resemble, as the ESA describes it, spinning tops suspended in the dark of space.

How a star builds its planetary system

Protoplanetary disks are the inevitable byproduct of stellar birth. When a dense clump of gas inside a molecular cloud collapses under its own gravity to ignite a star, the material that doesn’t fall directly onto the stellar core is left spinning in a thick disk of gas and dust around the newborn object. Over time, collisions within that disk cause dust grains to stick together, gradually building planetesimals — the rocky or icy building blocks from which planets eventually assemble.

Not all of this material makes the leap to full planetary status. The objects that fail to grow large enough are left behind as asteroids and comets, while the gas that escapes planetary incorporation is swept away by the young star’s radiation over tens of millions of years, gradually dispersing the disk entirely. What Webb is capturing in Tau 042021 and Oph 163131 is a snapshot of this process at its most active and formative stage — a window into conditions that our own solar system passed through more than four and a half billion years ago.

Multi-telescope observations and what the colors reveal

The images were produced using data from Webb’s NIRCam and MIRI instruments as part of Webb program #2562 (PI F. Ménard, K. Stapelfeldt). Together, these two cameras cover a broad range of infrared wavelengths, allowing astronomers to trace dust grains of different sizes distributed across the disk. The red, orange, and green hues visible in the images correspond to varying grain sizes as well as specific molecules, including molecular hydrogen (H₂), carbon monoxide (CO), and polycyclic aromatic hydrocarbons (PAHs) — complex organic molecules that are among the building blocks of interstellar chemistry.

Both images also incorporate data from the NASA/ESA Hubble Space Telescope, which contributes visible-light observations of the fine floating dust reflecting the central star’s light. For Oph 163131, the dataset goes further still, including observations from the Atacama Large Millimeter/submillimeter Array (ALMA). While Webb and Hubble resolve micrometer-scale dust grains, ALMA detects larger grains approximately one millimeter in size, concentrated in the disk’s central plane where conditions are most favorable for grain growth and eventual planet formation.

Crucially, the ALMA data for Oph 163131 reveals a gap in the inner disk — a cleared region that may already be the signature of a young planet in the process of forming, sweeping the surrounding dust as it orbits its star. If confirmed, it would represent one of the earliest detectable signs of planetary architecture emerging from raw disk material.

The distribution of dust shapes the planets that form

Beyond the visual spectacle, the scientific priority here is understanding how the spatial distribution of dust — both within the disk plane and in the diffuse layers above and below it — determines what kind of planetary system ultimately assembles. The composition, size, and location of dust grains influence whether a system builds rocky terrestrial planets close to the star, gas giants at intermediate distances, or icy bodies in the outer regions. By mapping these properties across disks in multiple star-forming regions, Webb is building the comparative framework needed to explain the extraordinary diversity of planetary systems discovered across our galaxy over the past three decades.

Tau 042021 and Oph 163131 are not isolated curiosities — they are laboratories for understanding the universal mechanics by which stars and planets come into being, including the mechanics that built our own cosmic home.

© 2026 SKYCR.ORG | Homer Dávila Gutiérrez, FRAS. Todos los derechos reservados. Prohibida la reproducción total o parcial sin autorización expresa. Fuente original: European Space Agency / NASA.