Pluto may have recently been demoted to the status of dwarf planet, but as astronomers learn more about this distant body, they are learning it behaves more like a planet than once believed. This frigid globe is able to interact with solar wind in a way that is much like its larger cousins.
The New Horizons team is still interpreting vast amounts of data recorded by the spacecraft as it whizzed past Pluto in the summer of 2015.
A Solar Wind Around Pluto (SWAP) instrument aboard the vehicle measured the effect the distant world had on charged particles from the far-distant sun. Pluto was found to affect the solar wind in a manner that appeared to be a hybrid between cometary and planetary effects.
Comets hardly change the course of this stream of electrically charged particles, and what little alteration that does occur takes place close to the body. Planets have a great effect on the solar wind, which is felt for significant distances. Astronomers found the river of particles was significantly affected by Pluto, but only for short distances from the icy sphere.
Until New Horizons arrived at the dwarf planet in July 2015, most astronomers believed heavy ions from Pluto's atmosphere would quickly be lost to space. The body was thought to be too small, and too far from the sun, to hold on to these molecules. The spacecraft found atmospheric ions in far greater concentrations than thought likely.
Pluto was also found to possess an ion tail extending 73,800 miles behind the frozen globe. The dwarf planet was found to only interfere with the solar wind just 1,844 miles in front of the body. This is roughly the distance between Chicago and Los Angeles.
"Comparing the solar wind-Pluto interaction to the solar wind-interaction for other planets and bodies is interesting because the physical conditions are different for each, and the dominant physical processes depend on those conditions," Heather Elliot of the Southwest Research Institute (SwRI) said.
Learning how Pluto interacts with the solar wind can help astronomers learn more about planets and comets in our own system, as well as how a solar wind from another star may behave.
Analysis of how Pluto interacts with the solar wind was published in the Journal of Geophysical Research: Space Physics.