Pluto To Become A Planet Again? Scientists Take Hard Look At Reclassifying Pluto

Will Pluto become a planet again? It turns out that experts are still flummoxed on what the downgraded planet’s correct classification should be.

The Christian Science Monitor reports that the International Astronomical Union’s decision in 2006 to demote Pluto to a dwarf planet is being looked at a second time.

As it currently stands, NASA’s New Horizons mission has another element of confusion. Pluto is in a category its own but is neither a comet nor a planet.

Readings obtained from a spacecraft’s flyby in July 2015 were revealed this week in the Journal of Geophysical Research. The files illustrate that Pluto’s interaction with the solar wind is unlike anything they’ve witnessed in our solar system before.

“The results are astonishing. We were fascinated and surprised,” said lead author David J. McComas, who manages the Solar Wind Around Pluto (SWAP) instrument on New Horizons and is a professor in Princeton University’s Department of Astrophysical Sciences and the vice president for the Princeton Plasma Physics Laboratory. “We’ve now visited all nine of the classical planets and examined all their solar wind interactions, and we’ve never seen anything like this.”

As the report describes, the solar wind is a plasma, containing charged particles that speed from the sun at 100 million miles-per-hour. Scientists have learned that when a comet is the path of the solar wind, a substantial region of gentle slowing of its force takes place. Venus and Mars, however, will cause “an abrupt diversion,” according to the report.

Science Alert more clearly describes it when it explains that the sun fires out plasma winds of highly charged particles in the solar system every second of every day.

It’s the way that those particles interact with the atmospheres surrounding various planets, dwarf planets, moons, and comets that relay what composition of gas that covers these cosmic bodies — in addition to the gravitational pull they’re able to maintain.

In an example provided, as solar winds encounter a comet, they’re gently slowed down over a long distance. The “very subtle influence that the comet’s gravitational pull has on these charged particles would only be seen very close to the comet.”

Most researchers believed Pluto fell into the former category of acting like a comet until this latest stream of information emerged.

Now, Pluto is considered a hybrid.

“This is an intermediate interaction, a completely new type. It’s not comet-like, and it’s not planet-like. It’s in-between,” said Dr. McComas.

The scientific team was able to pinpoint these conclusions due to SWAP’s ability to distinguish between heavy methane ions, the principal gas bleeding into space from Pluto’s atmosphere, and the lighter hydrogen ions, which originate in the sun.

They were shocked to learn that Pluto’s gravity was sturdy enough to retain heavy ions in its extended atmosphere. According to Michael Liemohn, a University of Michigan astrophysicist who helped edit the paper, researchers found that “only a wisp of atmosphere leaves the planet as ions.”

The data acquired by New Horizon’s SWAP instrument may hold more surprises. Scientists will continue analyzing data over the years in an effort to better understand Pluto’s interaction with the solar wind.

“These results speak to the power of exploration,” said Alan Stern, New Horizons’ principal investigator, in a NASA press release. “Once again we’ve gone to a new kind of place and found ourselves discovering entirely new kinds of expressions in nature.”

Will Pluto be reclassified as a planet once more after this study?

[Image via NASA/AP Images]