Observations from Deep Space: James Webb Telescope Investigates Trio of Dwarf Planets in Kuiper Belt

In an artist’s rendering, the newly identified celestial body known as ‘Sedna’ is depicted at the farthest reaches of the recognized solar system. Credit: NASA/JPL-Caltech

Employing the James Webb Space Telescope, astronomers have explored three dwarf planets within the Kuiper Belt, uncovering the presence of light hydrocarbons and intricate molecules. Such revelations not only deepen our comprehension of celestial objects in the extremities of the Solar System but also attest to the capabilities of the JWST in the realm of space science.

The Kuiper Belt, an expansive area on the periphery of our Solar System filled with myriad icy formations, remains a fertile ground for scientific inquiry. The identification and description of Kuiper Belt Objects (KBOs), alternatively termed as Trans-Neptunian Objects (TNOs), have offered fresh perspectives on the Solar System’s historical development. The arrangement of these KBOs serves as a gauge for the gravitational forces that have sculpted the Solar System, shedding light on its fluctuating history of planetary movements. Since the latter part of the 20th century, researchers have been keen to delve deeper into the nature and constituents of KBOs.

James Webb Space Telescope’s Contributions

The study of celestial bodies in the Solar System’s outermost regions is among the myriad goals of the James Webb Space Telescope (JWST). Through data acquired by the telescope’s Near-Infrared Spectrometer (NIRSpec), a global team of astronomers has scrutinized three dwarf planets in the Kuiper Belt: Sedna, Gonggong, and Quaoar. The observations disclosed intriguing details about these objects’ orbits and molecular make-up, including the detection of light hydrocarbons and intricate organic molecules that are thought to be the outcome of methane exposure to radiation.

The investigation was spearheaded by Joshua Emery, a Professor of Astronomy and Planetary Sciences at Northern Arizona University. Collaborating with him were researchers from various institutions, including NASA’s Goddard Space Flight Center, the Institut d’Astrophysique Spatiale (Université Paris-Saclay), the Pinhead Institute, the Florida Space Institute (University of Central Florida), the Lowell Observatory, the Southwest Research Institute, the Space Telescope Science Institute, American University, and Cornell University. A preliminary version of their research paper is currently under review and has been made available online.

Historical Context of Kuiper Belt Exploration

In spite of significant advancements in the field of astronomy and robotic exploration, our understanding of the Trans-Neptunian Region and the Kuiper Belt remains circumscribed. Until now, the only mission that has examined Uranus, Neptune, and their major moons was the Voyager 2 mission, which executed flybys in 1986 and 1989. Furthermore, the New Horizons mission holds the distinction of being the first to scrutinize Pluto and its moons in 2015, as well as being the sole spacecraft to encounter a KBO, namely Arrokoth, on January 1, 2019.

Expectations from the James Webb Space Telescope

The anticipated launch of the JWST was a momentous occasion for astronomers. Beyond its capabilities to examine exoplanets and early galaxies, the telescope’s potent infrared imaging technology has also been focused on our immediate cosmic environment, yielding fresh imagery of Mars, Jupiter, and its major moons. For their particular study, Emery and his associates referred to near-infrared data collected by Webb on the dwarf planets Sedna, Gonggong, and Quaoar. These celestial bodies have diameters around 1,000 km (approximately 620 miles), categorizing them as Dwarf Planets under the IAU classification.

Insights into Dwarf Planets

Emery conveyed to Universe Today via email that these celestial objects are of particular interest because of their dimensions, orbits, and elemental compositions. Other Trans-Neptunian bodies like Pluto, Eris, Haumea, and Makemake have managed to preserve volatile ices such as nitrogen and methane on their surfaces. Haumea stands as an exception, having apparently lost its volatiles due to a large-scale impact. Emery and his team aimed to assess if Sedna, Gonggong, and Quaoar exhibit similar volatile characteristics.

The orbits of these dwarf planets are diverse, with Sedna belonging to the inner Oort Cloud and having an extremely elliptical orbit, whereas Quaoar follows a relatively circular trajectory. This places them in distinct thermal and radiation environments. Emery and his team wished to explore how these varying orbits might influence their surface properties. Furthermore, they found other intriguing ices and complex organic molecules on the surfaces of these celestial bodies.

Utilizing data from Webb’s NIRSpec instrument, the researchers observed all three objects at near-infrared wavelengths, offering valuable insights into their molecular structure and surface composition. This led to the discovery of abundant ethane and other hydrocarbons, especially on Sedna. The findings align with recent studies led by Dr. Will Grundy and Chris Glein, which suggests that methane on other dwarf planets is not primordial but is being processed internally before being released to the surface.

Conclusions and Implications

These discoveries could potentially be groundbreaking for the scholarly investigation of KBOs, TNOs, and other celestial objects in the outer Solar System. They provide a new understanding of the formation of these bodies beyond the Frost Line and suggest that these objects may undergo interior reprocessing of ices. Moreover, the study also showcases the remarkable capabilities of the JWST in delivering high-quality data, aiding in the understanding of both our immediate cosmic neighborhood and the broader Universe.

Adapted from an article originally published on Universe Today.

Reference: “A Comprehensive Study of Three Dwarf Planets: Identification of Ices and Organics on Sedna, Gonggong, and Quaoar through JWST Spectroscopy” by J.P. Emery, I. Wong, R. Brunetto, J.C. Cook, N. Pinilla-Alonso, J.A. Stansberry, B.J. Holler, W.M. Grundy, S. Protopapa, A.C. Souza-Feliciano, E. Fernández-Valenzuela, J.I. Lunine and D.C. Hines, 26 September 2023, Astrophysics > Earth and Planetary Astrophysics. arXiv:2309.15230

Frequently Asked Questions (FAQs) about James Webb Space Telescope

More about James Webb Space Telescope

• James Webb Space Telescope Official Website
• Research Paper on Observations of Kuiper Belt Dwarf Planets
• NASA’s Goddard Space Flight Center
• Institut d’Astrophysique Spatiale
• Northern Arizona University Department of Astronomy
• Southwest Research Institute
• The Lowell Observatory
• The Space Telescope Science Institute
• Florida Space Institute
• Pinhead Institute
• American University
• Cornell University
• Near-Infrared Spectrometer (NIRSpec)
• Introduction to the Kuiper Belt