Webb reveals ancient surface of Pluto and other celestial bodies for the first time
Scientists at NASA for the first time have been able to observe the make up of Pluto and other small and icy celestial bodies in the outer solar system.
They had expected to find that the surfaces of the bodies, known as “trans-Neptunian” objects, were dominated by frozen molecules that are gases or liquids on the surface of Earth, like water, methane, and carbon dioxide. They believed that radiation from the sun and solar system would alter that chemistry, creating new and more complex hydrocarbon molecules like methanol and ethane.
New data from the James Webb Space Telescope’s Near Infrared Spectrograph instrument (NIRSpec) has “confirmed this, but in unexpected ways, and in unprecedented detail,” NASA explained in a blog post on Wednesday.
The findings were published in the journal Nature Astronomy.
To reach these conclusions, the researchers used data from NIRSpec, one of four science instruments on the Webb telescope.
Spectrographs scatter light from an object into a spectrum: a chart or a graph that shows the intensity of light being emitted over a range of energies. Analyzing that chart can reveal an object’s temperature, mass, and chemical composition.
With the data from NIRSpec – which detects near-infrared wavelengths of light and is capable of observing more than 100 bodies at once – the scientists were able to study more than 75 trans-Neptunian objects.
The objects range in size, with diameters less than tens of miles to 1,500-mile-diameter dwarf planets. The objects travel on orbits comparable in size or even larger than Neptune’s orbit. NASA says their paths reflect the migration of the ice giants Uranus and Neptune during the early formation of the solar system.
Data from nearly 60 trans-Neptunian objects helped to identify three “spectral classes” characterizing the spectra they analyzed. Spectral classes are how astronomers categorize stars based on their light spectrum and temperature.
The three categories are distinct in their color and shape. Notably, they are generated by molecules that contain water and feature carbon dioxide ice, and silicate-rich dust.
Those that were shaped like bowls formed closer to the sun and were subject to higher temperatures, the space agency said.
The data came from the DiSCo-TNOs program, which is comprised of a group of international researchers.
Looking forward, researchers will work on imaging and spectroscopy of a handful of these objects and their satellites.
