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**World news, outside the US.** Original rationale: unless moderated, internal US news and politics often dominates world news in English, because of its demographic position. This magazine/community is to post news and articles from around the globe, but posts must have a mainly non-US component or focus. Submissions related in some way to the Alan Weisman book *The World Without Us*, which is about what would happen if humans suddenly disappeared from the planet, are also welcome. :)

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A Planetary Disk in the Orion Nebula is Destroying and Replenishing Oceans of Water Every Month (www.universetoday.com)

submitted 8 months ago by livus@kbin.social to c/worldwithoutus@kbin.social

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Astronomers used JWST to study molecules in a protoplanetary disk in the Orion Nebula to follow the destruction and replenishment of water. Planet-forming disks are places of chaotic activity. Not only do planetesimals slam together to form larger worlds, but it now appears that the process involves the destructive recycling of water within a disk. That’s the conclusion from scientists studying JWST data from a planetary birth crèche called d203-506 in the Orion Nebula.

The data they studied suggest that an amount of water equivalent to all of Earth’s oceans is created and replenished in a relatively short period—about a month. According to study co-lead Els Peeters at Western University in Canada, it was relatively easy to discover this process in the protoplanetary disk. “This discovery was based on a tiny fraction of our spectroscopic data,” she said. “It is exciting that we have so much more data to mine and I can’t wait to see what else we can find.”

The Orion Nebula is a vast active star- and planet-forming region and the d203-506 protoplanetary disk lies within it at a distance of about 1,350 light-years away from Earth. Astronomers study the nebula to understand all aspects of star birth since there are so many newborn stars there. In addition, many are surrounded by disks of gas and dust, called protoplanetary disks (proplyds, for short). Those regions are excellent places to observe planet-formation processes, and particularly the interplay between the young stars and their disks.

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[–] livus@kbin.social 2 points 8 months ago (1 children)

From the article:

Most of Earth’s water got delivered to the forming planet over millions of years. It melted or outgassed to form the oceans, rivers, and lakes we see today. But, some fraction of the water in our system’s birth disk probably went through a “freeze-thaw” cycle within the disk. That happened when the Solar System was still just a disk of gas and dust. The water was essentially destroyed and then re-formed at higher temperatures.

We can’t see that effect anymore in our system. But, astronomers can point telescopes at other proplyds to see if the same process happens there. That’s what Peeters and her team did. They used JWST to look at d203-506. There, bright young stars flood the nearby regions in the proplyd with intense ultraviolet radiation. The UV breaks up water molecules to form hydroxyl molecules and that process also releases infrared light. JWST can search out that light and report back on how much hydroxyl is in the birth cloud. The team estimates that the process in d203-506 regularly destroys and replenishes about an Earth oceans-full of water each month.

Formation of the Solar System Implications

The d203-506 system is currently forming new worlds, but it began as a cloud of gas and dust without a star. That’s exactly how our own Solar System began—as a cloud of gas and dust more than 4.5 billion years ago. The cloud it formed from was a cold, dark nebula containing some amount of water ice, or water-rich material. Something nudged the cloud to coalesce into a region of higher density, and that continued to shrink in on itself under the force of gravity. Temperatures rose, and eventually, a protostar began to form. Ultraviolet from the Sun irradiated the birth cloud, and that led to a similar water-destroying and replenishing activity. Heat and radiation from the Sun also forced lighter elements to migrate out to cooler regions in the system.

So, d203-506 makes a great analog to study the water cycle in the infant Solar System. Based on this JWST data, it’s very likely that water in Earth’s oceans went through this same process. Eventually, that water made its way to the planetesimals and icy bodies that helped form the worlds of the Solar System...

[–] theodewere@kbin.social 2 points 8 months ago

The UV breaks up water molecules to form hydroxyl molecules and that process also releases infrared light. JWST can search out that light and report back on how much hydroxyl is in the birth cloud.

those are some nice optics