Starship Asterisk*

Ann wrote: ↑Sun Nov 17, 2024 4:57 am

AVAO wrote: ↑Sat Nov 16, 2024 7:45 pm
"Reasons Why Pluto Is a Dwarf Planet

Pluto orbits the Sun and meets the second criterion, which is a nearly round shape. However, it has difficulty with the other criteria for planethood.

It resides in the Kuiper Belt, a region of small icy bodies, signifying that it has not cleared its neighborhood of other objects. But, clearing an orbit is about mass and not just about location. Pluto is about two-thirds the size of Earth’s moon, but only one-sixth of its mass. It contains a larger proportion of ice to rock than a typical planet and just doesn’t pull in the debris it encounters on its journey around the Sun.

The other issues concern Pluto’s moon, Charon. Pluto has at least five moons, but Charon is special because it’s about half the size of Pluto. It is so massive that the center of mass (barycenter) of the Pluto-Charon system doesn’t actually reside within Pluto, but in the space between the two bodies. Due to this unique characteristic, some argue that Pluto and Charon are a binary (dwarf) planet system. In other words, Pluto and Charon are essentially satellites of each other. However, the IAU has yet to officially recognize binary dwarf planets as a separate category."

Source: https://sciencenotes.org/is-pluto-a-planet/

Is it important if Pluto is called a planet or a dwarf planet? Brian Cox doesn't think so.

"It's a beautiful world", he says.

https://youtu.be/cO87BJbwes4?t=447

Ann

AVAO wrote: ↑Sat Nov 16, 2024 7:45 pm
"Reasons Why Pluto Is a Dwarf Planet

Pluto orbits the Sun and meets the second criterion, which is a nearly round shape. However, it has difficulty with the other criteria for planethood.

It resides in the Kuiper Belt, a region of small icy bodies, signifying that it has not cleared its neighborhood of other objects. But, clearing an orbit is about mass and not just about location. Pluto is about two-thirds the size of Earth’s moon, but only one-sixth of its mass. It contains a larger proportion of ice to rock than a typical planet and just doesn’t pull in the debris it encounters on its journey around the Sun.

The other issues concern Pluto’s moon, Charon. Pluto has at least five moons, but Charon is special because it’s about half the size of Pluto. It is so massive that the center of mass (barycenter) of the Pluto-Charon system doesn’t actually reside within Pluto, but in the space between the two bodies. Due to this unique characteristic, some argue that Pluto and Charon are a binary (dwarf) planet system. In other words, Pluto and Charon are essentially satellites of each other. However, the IAU has yet to officially recognize binary dwarf planets as a separate category."

Source: https://sciencenotes.org/is-pluto-a-planet/

Chris Peterson wrote: ↑Sat Nov 16, 2024 7:59 pm

AVAO wrote: ↑Sat Nov 16, 2024 7:45 pm

JimT wrote: ↑Sat Nov 16, 2024 6:33 pm Astonishing image in any case, especially to one who was a teenager in 1957, and can well remember the excitement when Sputnik I was launched in October of that year.

"Reasons Why Pluto Is a Dwarf Planet

Pluto orbits the Sun and meets the second criterion, which is a nearly round shape. However, it has difficulty with the other criteria for planethood.

It resides in the Kuiper Belt, a region of small icy bodies, signifying that it has not cleared its neighborhood of other objects. But, clearing an orbit is about mass and not just about location. Pluto is about two-thirds the size of Earth’s moon, but only one-sixth of its mass. It contains a larger proportion of ice to rock than a typical planet and just doesn’t pull in the debris it encounters on its journey around the Sun.

The other issues concern Pluto’s moon, Charon. Pluto has at least five moons, but Charon is special because it’s about half the size of Pluto. It is so massive that the center of mass (barycenter) of the Pluto-Charon system doesn’t actually reside within Pluto, but in the space between the two bodies. Due to this unique characteristic, some argue that Pluto and Charon are a binary (dwarf) planet system. In other words, Pluto and Charon are essentially satellites of each other. However, the IAU has yet to officially recognize binary dwarf planets as a separate category."

Source: https://sciencenotes.org/is-pluto-a-planet/

I consider everything that orbits the Sun to be a planet, and beyond that it's just the class of planet. Pluto is as much a planet as Jupiter. Or an asteroid. The IAU definition doesn't change reality, it's just a usage convention for those who write academic papers.

AVAO wrote: ↑Sat Nov 16, 2024 7:45 pm

JimT wrote: ↑Sat Nov 16, 2024 6:33 pm

JimT wrote: ↑Sat Nov 16, 2024 6:25 pm Clarification, just for the record:

Tenzing Montes
Feature type Mountain range
Location Western Sputnik Planitia, Pluto
Discoverer New Horizons
Eponym Tenzing Norgay

"The Tenzing Montes /ˈtɛnzɪŋ ˈmɒntiːz/ (formerly Norgay Montes) are a range of icy mountains on Pluto, bordering the southwest region of Sputnik Planitia and the nearby Hillary Montes...

The mountains, first viewed by the New Horizons spacecraft on 14 July 2015, and announced by NASA on 15 July 2015, are named after the Nepalese mountaineer Tenzing Norgay...The mountains were informally called Norgay Montes by the New Horizons team, but that name was later changed from Norgay to Tenzing. On 7 September 2017..."

— Wikipedia

Astonishing image in any case, especially to one who was a teenager in 1957, and can well remember the excitement when Sputnik I was launched in October of that year.

"Reasons Why Pluto Is a Dwarf Planet

Pluto orbits the Sun and meets the second criterion, which is a nearly round shape. However, it has difficulty with the other criteria for planethood.

It resides in the Kuiper Belt, a region of small icy bodies, signifying that it has not cleared its neighborhood of other objects. But, clearing an orbit is about mass and not just about location. Pluto is about two-thirds the size of Earth’s moon, but only one-sixth of its mass. It contains a larger proportion of ice to rock than a typical planet and just doesn’t pull in the debris it encounters on its journey around the Sun.

The other issues concern Pluto’s moon, Charon. Pluto has at least five moons, but Charon is special because it’s about half the size of Pluto. It is so massive that the center of mass (barycenter) of the Pluto-Charon system doesn’t actually reside within Pluto, but in the space between the two bodies. Due to this unique characteristic, some argue that Pluto and Charon are a binary (dwarf) planet system. In other words, Pluto and Charon are essentially satellites of each other. However, the IAU has yet to officially recognize binary dwarf planets as a separate category."

Source: https://sciencenotes.org/is-pluto-a-planet/

JimT wrote: ↑Sat Nov 16, 2024 6:33 pm

JimT wrote: ↑Sat Nov 16, 2024 6:25 pm Clarification, just for the record:

Tenzing Montes
Feature type Mountain range
Location Western Sputnik Planitia, Pluto
Discoverer New Horizons
Eponym Tenzing Norgay

"The Tenzing Montes /ˈtɛnzɪŋ ˈmɒntiːz/ (formerly Norgay Montes) are a range of icy mountains on Pluto, bordering the southwest region of Sputnik Planitia and the nearby Hillary Montes...

The mountains, first viewed by the New Horizons spacecraft on 14 July 2015, and announced by NASA on 15 July 2015, are named after the Nepalese mountaineer Tenzing Norgay...The mountains were informally called Norgay Montes by the New Horizons team, but that name was later changed from Norgay to Tenzing. On 7 September 2017..."

— Wikipedia

Astonishing image in any case, especially to one who was a teenager in 1957, and can well remember the excitement when Sputnik I was launched in October of that year.

JimT wrote: ↑Sat Nov 16, 2024 6:25 pm Clarification, just for the record:

Tenzing Montes
Feature type Mountain range
Location Western Sputnik Planitia, Pluto
Discoverer New Horizons
Eponym Tenzing Norgay

"The Tenzing Montes /ˈtɛnzɪŋ ˈmɒntiːz/ (formerly Norgay Montes) are a range of icy mountains on Pluto, bordering the southwest region of Sputnik Planitia and the nearby Hillary Montes...

The mountains, first viewed by the New Horizons spacecraft on 14 July 2015, and announced by NASA on 15 July 2015, are named after the Nepalese mountaineer Tenzing Norgay...The mountains were informally called Norgay Montes by the New Horizons team, but that name was later changed from Norgay to Tenzing. On 7 September 2017..."

— Wikipedia

Astonishing image in any case, especially to one who was a teenager in 1957, and can well remember the excitement when Sputnik I was launched in October of that year.