“It always has been, and it always will be,” Will Grundy of Lowell Observatory in Flagstaff, Arizona is quoted on Sciencenews.org. But he has a challenge. How will he convince the world? How will a forty year old man in Chitipa in Malawi be convinced otherwise.
Now he just has to convince the world of that.
For years, centuries, the word planet has meant “wanderer.” The wanderer had included the sun, the moon, Mercury, Venus, Mars, Jupiter and Saturn.
However over the years of debates, the moon and sun were dropped from the definition. But Pluto was included, after its discovery in 1930. That idea of a planet as a rocky or gaseous body that orbited the sun stuck, all the way up until 2006.
The challenge is the definition of the planet. The way it is defined and application of the definition has been varying.
The International Astronomical Union sensing the challenge described a planet as “any round object that orbits the sun and has moved any pesky neighbors out of its way, either by consuming them or flinging them off into space.” This is where Pluto fails to fit in. Especially when compared to the last part of the definition. It’s perhaps the reason it’s called a “dwarf planet.”
The definition has flaws.
It forgets and overlooks thousands of “exotic worlds that orbit other stars and also rogue ones with no star to call home.” Secondly, studies show that “it requires that a planet cut a clear path around the sun.” But no planet does that; Earth, Mars, Jupiter and Neptune share their paths with asteroids, and objects crisscross planets’ paths all the time.
Grundy and the team members of NASA’s New Horizons mission to Pluto have meticulously laid out these arguments against the IAU definition of a planet March 21 at the Lunar and Planetary Science Conference in The Woodlands, Texas.
There is need for a simple definition. Grundy says the definition should be “any round object in space that is smaller than a star.”
“There’d be about 110 known planets in our solar system,” Grundy quoted as saying.
The reason for the tweak is to maintain the focus on the features — the physics, the geology, the atmosphere — of the world itself, rather than worry about what’s going on around it, he says.
The New Horizons mission has shown that Pluto is an interesting world with active geology, an intricate atmosphere and other features associated with planets in the solar system. It makes no sense to write Pluto off because it doesn’t fit one criterion. Grundy seems convinced the public could easily readopt the small world as a planet. Though he admits astronomers might be a tougher sell.
“People have been using the word correctly all along,” Grundy says. He suggests we stick with the original definition. That’s his plan.
For Ipyana Mwaungulu in Chitipa, he still has to follow the debate.
No comments:
Post a Comment