It has been a difficult year for Pluto. The deep planet, first discovered in 1930 by astronaut Clyde Tombaugh, was removed from its most prestigious planet status in 2006 by the International Astronomical Union (IAU) because orbit his crossing over Neptune. A new set of IAU criteria dictates that a planet must orbit the sun, be spherical as a result of gravity, and “illuminate” the “neighborhood” around the orbit, saying that the presence it is the largest. Pluto met the first and second editions but not the third, releasing it to the smallest deep planet designation.
That determination led to an ongoing debate as to whether Pluto was actually earning his position. The latest and most powerful argument comes courtesy of a paper from researchers at the University of Central Florida Space Institute and published in the journal Planetary Science Icarus. On the record, the first author Philip Metzger states that no one since 1802 has used the landfill argument to describe a planet. Describing the IAU’s definition as “sloppy,” Metzger and his co-authors reveal that no one else has separated asteroids from planets using the cleanup command. Planets, the paper argues, should not be confined to dynamic descriptions of bodies that may change over time.
“We now have a list of more than 100 recent examples of planetary scientists using the word planet in a way that contradicts the IAU definition, but they do so because it is useful to in terms of action, “Metzger said in a statement. “It’s a sloppy explanation. They didn’t say what they meant by clearing the orbit. If you take that literally, there are no planets, because no planet is cleaning its orbit. orbit. “
Metzger claims instead for a planet to gain its status due to being large enough to achieve a spherical shape under the influence of gravity that triggers geological changes.
Speaking to CNN, IAU spokeswoman Lars Lindberg Christensen said a move could be put forward so that the group could re-evaluate the classification but no one had done so yet.
Whatever Pluto is or may one day be, it was a planet to Tombaugh, who was not around long enough to experience the reclassification. He died in 1997. In 2015, his ashes, attached to the New Horizons space probe, went into Pluto’s orbit after nine years of orbit.
[h/t Science Alert]