Pluto’s solar wind interaction more like a planet’s
Data from New Horizons has found that Pluto, in its interaction with the solar wind, behaves more like a planet than a comet.
Previously, most researchers thought that Pluto was characterized more like a comet, which has a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus. Instead, like a car that’s part gas- and part battery-powered, Pluto is a hybrid, the researchers say. “This is an intermediate interaction, a completely new type. It’s not comet-like, and it’s not planet-like. It’s in-between,” McComas said. “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.”
…Pluto continues to confound. Since it’s so far from the sun – an average of about 5.9 billion kilometers (3.7 billion miles) – and because it’s so small, scientists thought Pluto’s gravity would not be strong enough to hold heavy ions in its extended atmosphere. But, “Pluto’s gravity clearly is enough to keep material sufficiently confined,” McComas said. Further, the scientists found that very little of Pluto’s atmosphere is comprised of neutral particles converted to electrically charged ions and swept out into space.
As I’ve written previously, we simply don’t know enough yet about planets to come up with a reasonable definition. As far as I’m concerned, Pluto will remain a planet until we do.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Data from New Horizons has found that Pluto, in its interaction with the solar wind, behaves more like a planet than a comet.
Previously, most researchers thought that Pluto was characterized more like a comet, which has a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus. Instead, like a car that’s part gas- and part battery-powered, Pluto is a hybrid, the researchers say. “This is an intermediate interaction, a completely new type. It’s not comet-like, and it’s not planet-like. It’s in-between,” McComas said. “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.”
…Pluto continues to confound. Since it’s so far from the sun – an average of about 5.9 billion kilometers (3.7 billion miles) – and because it’s so small, scientists thought Pluto’s gravity would not be strong enough to hold heavy ions in its extended atmosphere. But, “Pluto’s gravity clearly is enough to keep material sufficiently confined,” McComas said. Further, the scientists found that very little of Pluto’s atmosphere is comprised of neutral particles converted to electrically charged ions and swept out into space.
As I’ve written previously, we simply don’t know enough yet about planets to come up with a reasonable definition. As far as I’m concerned, Pluto will remain a planet until we do.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
“As I’ve written previously, we simply don’t know enough yet about planets to come up with a reasonable definition. As far as I’m concerned, Pluto will remain a planet until we do.”
Mr. Zimmerman, I agree that a more reasonable definition of what a planet is would be in order as until 2006 Pluto was one and now is not so much. As our knowledge increases, I would submit that Pluto and other Kuiper objects will not be considered so. Remnants from the forming of the Solar System that managed become spheres and have shown some aspects of our growing knowledge about such things does not make a planet IMHO.
I propose a rule that states that only bodies discovered prior to 1931 be considered for planetary status…. ;-)
But seriously, I think some consideration should be given to history and tradition. Pluto has been thought of as a planet almost since the moment it was discovered.
Not to mention that these other bodies took considerably more time and effort than Pluto to even locate in the first place. They may rival or even surpass Pluto in size, but IIRC they are much further away. Truly they are Kuiper belt objects, whereas Pluto is much more a part of our little Sol-system.
Heck , Pluto even comes closer to the sun than Neptune during part of its orbit, yes?
A planet doesn’t have to orbit a star. The defining quality of a planet is it’s big enough to be round. This means some moons could also be considered planets. Colonists everywhere will certainly consider their homes to be planets.
The traditional planets are those that orbit a star. One day we may find a moon the size of the earth… would that not be a planet?