Unraveling the Mystery of Cosmic Crystals
Scientists have been puzzled for a long time about the existence of crystalline silicates or cosmic crystals in the comets that inhabit the frigid outer reaches of our solar system. Crystals typically need intense heat to form, yet these icy bodies are found in the extraordinarily cold Kuiper Belt and Oort Cloud. Thanks to a powerful space telescope, we now have a better understanding of these intriguing phenomena.
The telescope's observations have provided the first definitive proof that links the formation of these cosmic crystals to extremely hot, inner regions of the gas and dust disk surrounding a young star that's still forming. The findings also indicate a strong outflow capable of ferrying these crystals to the outer regions of the disk. In comparison to our solar system, which is mostly cleared of dust and fully formed, these cosmic crystals are forming somewhere between the positions of the Sun and Earth.
Star Winds and Cosmic Crystals
The space telescope has delivered detailed mid-infrared observations of a protostar, known as EC 53. These observations indicate that the strong winds generated by the star's disk could be responsible for launching these newly formed cosmic crystals into distant, cold areas of its protoplanetary disk where comets might eventually form.
"The layered outflows from EC 53 may be lifting these newly formed cosmic crystals and transferring them outwards, like they're on a cosmic highway," said the lead investigator of the research. "The telescope not only showed us which types of silicates are present in the dust near the star, it also revealed where they are both before and during a burst."
The research team used the telescope's mid-infrared instrument to collect two sets of detailed spectra. These allowed them to identify specific elements and molecules and determine their structures. They then mapped where everything is when EC 53 is "quiet" and gradually eating away at its disk, as well as when it's more active during an outburst phase.
A Predictable Star
EC 53 is a fascinating object of study. Unlike other young stars with erratic outbursts or outbursts that last for hundreds of years, EC 53's behavior is highly predictable. About every 18 months, this protostar starts a 100-day burst phase, intensifying its pace and consuming nearby gas and dust. Some of this intake is then ejected as powerful jets and outflows, which could be responsible for flinging some of the freshly formed crystals into the outskirts of the protoplanetary disk.
"It's incredibly impressive that we can find specific silicates in space, including forsterite and enstatite near EC 53," said a co-author of the study. "These are common minerals on Earth. The main ingredient of our planet is silicate." For many decades, research has identified cosmic crystals not only on comets in our solar system but also in distant protoplanetary disks around other, slightly older stars — but couldn't pinpoint how they got there. Now, with this new data, researchers have a better understanding of how these conditions might be possible.
"It's incredibly impressive that the telescope can not only show us so much, but also where everything is," said another co-author of the study. "Our research team mapped how the crystals move throughout the system. We've effectively shown how the star creates and distributes these superfine particles, which are each significantly smaller than a grain of sand."
Looking Ahead
EC 53 is still enveloped in dust and may remain so for another 100,000 years. Over millions of years, while a young star's disk is heavily populated with small grains of dust and pebbles, countless collisions will occur that may slowly build up a range of larger rocks. This could eventually lead to the formation of terrestrial and gas giant planets. As the disk settles, both the star itself and any rocky planets will finish forming, the dust will largely clear, and a Sun-like star will remain at the center of a cleared planetary system, with cosmic crystals scattered throughout.
EC 53 is part of the Serpens Nebula, a region brimming with actively forming stars, located 1,300 light-years away from Earth.
The space telescope that made these discoveries is the world's leading space science observatory. It is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it.
