In this artist’s conception, a newly discovered planet-like object, called Sedna, is located at the outer edge of the known solar system. Image source: NASA/JPL-Caltech
using the James Webb Space TelescopeAstronomers observed three dwarf planets in… the Kuiper BeltAnd the discovery of light hydrocarbons and complex molecules. These results improve our understanding of objects beyond the solar system and highlight the capabilities of the James Webb Space Telescope for space exploration.
That Kuiper beltThe vast region at the edge of our solar system, inhabited by countless icy bodies, is a repository of scientific discoveries. Detection and characterization Kuiper belt objects (KBO), sometimes referred to as Trans-Neptune objects (TNO Agency) gives rise to new understanding of the history of the solar system. The release of Kuiper belt objects is an indicator of the gravitational currents that shaped the solar system and reveals the dynamic history of planetary migration. Since the late 20th century, scientists have been interested in taking a closer look at Kuiper Belt objects to learn more about their orbits and composition.
James Webb Space Telescope Observations
Studying objects outside the solar system is one of the many goals of the James Webb Space Telescope (JWST). Using data obtained by Webb Near infrared spectrometer (NIRSpec), an international team of astronomers has observed three dwarf planets in the Kuiper Belt: Sedna, Jungjung, and Kwar. These observations reveal many interesting things about its orbit and composition, including light hydrocarbons and complex organic molecules that are thought to be products of methane irradiation.
The research was led by Joshua Emery, a professor of astronomy and planetary science at Northern Arizona University. He was joined by researchers from NASA’s Goddard Space Flight Center (GSFC). Institute for Spatial Astrophysics (Paris-Saclay University). Pini Head InstituteThat Florida Space Institute (University of Central Florida). Observatorium LowellThat Southwest Research Institute (Sweet), then Space Telescope Science Institute (STScI), American University. and Cornell University. A preprint of their paper has appeared online and is being reviewed for publication by Icarus.
Since last flying by the Arrokoth object in the Kuiper Belt, the New Horizons mission has explored objects in the Kuiper Belt and carried out heliosphere and astrophysical observations. Image credit: NASA/JHUAPL/SwRI//Roman Tkachenko
History of Kuiper Belt exploration
Despite all the advances in astronomy and robotic exploration, our knowledge of Trans-Neptunian and the Kuiper Belt is still limited. So far, the only task of studying Uranus, NeptuneTheir main satellites are explorer 2 These missions were flown by these two ice giants in 1986 and 1989 respectively. In addition, new horizons The mission was the first spacecraft to study Pluto and its satellites (in July 2015) and the only one to ever discover a Kuiper Belt object, which occurred on January 1, 2019, when it flew close to the Kuiper Belt known as Arrokoth.
Astronomer’s forecast from JWST
This is one of the many reasons astronomers are eagerly awaiting the launch of the James Webb Space Telescope. In addition to studying the oldest exoplanets and galaxies in the universe, powerful infrared imaging capabilities have also been directed into our backyards, revealing new images… MarsJupiterand him Biggest satellite. For their research, Emery and his colleagues relied on near-infrared data obtained by Webb for three planets in the Kuiper Belt – Sedna, Gungong and Kuar. These objects are about 1,000 km (620 miles) in diameter, which means they are within it Classification of dwarf planets from the International Astronomical Union.
Insight into dwarf planets
As Emery told Universe Today via email, these objects are of great interest to astronomers because of their size, orbit and composition. Other trans-Neptunian objects – such as Pluto, Eris, Haumea, and Makemake – have retained volatile ices on their surfaces (nitrogen, methane, etc.). The only exception is Haumea, which loses its (apparently) significant volatile impact. As Emery said, they wanted to know whether Sedna, Goonggong, and Quaoar also had similar volatiles on their surfaces:
“Previous research has shown that they may be able to do so. Although they are roughly the same size, their orbits are different. Sedna is an object of the inner Oort Cloud with a perihelion of 76 AU and a peak around 1,000 AU. Gunggung is in an elliptical orbit Also very extreme, with a perihelion of 33 AU and an apogee of ~100 AU, Kwar is in a relatively circular orbit near 43 AU. These orbits place objects in different temperature regimes and different radiation environments (Sedna, for example, “It spends most of its time outside the Sun’s heliosphere. We want to investigate how these different orbits affect the surface. There are also other interesting ices and complex organic materials on the surface .”
Image from one of two PRISM observations at Sedna, Goonggong, and Quoar. Credit: Emery, JP et al. (2023)
Using data from the Webb NIRSpec instrument, the team observed all three objects in low-resolution prism mode at wavelengths of 0.7 to 5.2 micrometers (µm) – placing them all in the near-infrared spectrum. Additional Quaoar observations were made from 0.97 to 3.16 μm using a medium resolution grid with tenfold spectral resolution. The resulting spectrum revealed some interesting things about the TNO object and its surface composition, Emery said:
“We found an abundance of ethane (C2H6) in all three objects, especially in Sedna. Sedna also exhibits acetylene (C2H2) and ethylene (C2H4). The abundance is orbitally related (mostly at Sedna, less at Gunggung, and least at Kuwar), which is consistent with the Relative temperature and radiation environment. These molecules are products of direct irradiation of methane (CH4). If ethane (or something else) has been on the surface for a long time, it will turn into Since we still see it, we doubt that the Roof should be fueled with methane (CH4) on a regular basis.
These findings are consistent with those presented in two recent studies led by Dr. Will Grundy, astronomer at Lowell Observatory and NASA research associate. new horizons mission, and Chris Glenn, planetary scientist and geochemist at SwRI. In both studies, Grundy, Glenn and their colleagues measured the deuterium/hydrogen (D/H) ratio in methane at Iris and Makemake and concluded that the methane was not primitive. Instead, they argue, the ratio results from internal methane processes released to the surface.
“We suggest the same applies to Sedna, Gonggong and Quaoar,” Emery said. “We also saw that the spectra of Sedna, Goonggong, and Quaoar were different from those of the smaller KBOs. There was talk at two recent conferences showing that the James Webb Space Telescope data for the smaller KBOs clusters in three groups, none of which are similar to Sedna, Gonggong, and Quaoar. They agree that this is the result even though our three larger bodies have different geothermal histories.
Comparison of the eight largest TNOs with Earth (all to scale). Credit: NASA/Lexicon
Implications of the results
These results could have important implications for the study of Kuiper Belt objects, TNOs, and other objects outside the solar system. This includes new insights into the formation of objects beyond the freezing line in planetary systems, which refers to the line beyond the freezing point of volatile compounds. In our solar system, the trans-Neptunian region corresponds to the nitrogen line, where objects hold large amounts of volatile materials with very low freezing points (such as nitrogen, methane, and ammonia). Emery said the findings also illustrate the type of evolutionary processes that occurred in the body in this region:
“The main impact may be to find volumes where Kuiper Belt objects become warm enough for internal reprocessing of ancient ice, and perhaps even differentiation. We should also be able to use these spectra to better understand the radiation processing of ice surfaces in the future.” outer solar system.” Future research will also be able to look in more detail at the stability of the volatiles and possible atmospheres of these objects above any part of their orbits.
The results of this research also show the capabilities of the James Webb Space Telescope, which has proven its effectiveness several times since it was put into operation early last year. It also reminds us that in addition to enabling new insights and new discoveries about distant planets, galaxies, and the large-scale structure of the universe, Webb can also reveal things about our own small corner of the universe.
“The James Webb Space Telescope data is incredible,” added Emery. “This telescope allows us to obtain spectra at longer wavelengths than can be obtained from Earth, allowing us to detect these icicles. Often, when observing in new wavelength ranges, the quality of the raw data can be very poor. The James Webb Telescope has not yet been opened. This spacecraft not only provides a new wavelength range, but also provides extraordinary sensitive and high-quality data for a variety of surface materials in the outer solar system.
Adapted from an article first published in Current universe.
Reference: “A Tale of Three Dwarf Planets: Ice and Organics in Sedna, Gunggong, and Kuwar from JWST Spectroscopy” by JP Emery, I. Wong, R. Brunoto, JC Cook, N. Pinilla-Alonso, JA Stansbury, BJ Holler, WM Grundy, S. Protopapa, AC Souza-Feliciano, E. Fernández-Valenzuela, JI Lunine and DC Hines, 26 September 2023, Astrophysics > Physics of the earth and planets Astrophysics.
arXiv:2309.15230
2023-10-22 13:37:48
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