Posted on 02/28/2019 8:50:11 PM PST by SunkenCiv
The records include dates and times, Cesario said, which makes them useful to modern-day astronomers.
Planet Nine, if it exists, would have about 10 times the mass of Earth and orbit 20 times farther from the sun than Neptune does...
Scientists suspect the existence of Planet Nine because it would explain some of the gravitational forces at play in the Kuiper Belt, a stretch of icy bodies beyond Neptune. But no one has been able to detect the planet yet, though astronomers are scanning the skies for it with tools such as the Subaru Telescope on Hawaii's Mauna Kea volcano.
Medieval records could provide another tool, said Pedro Lacerda, a Queen's University astronomer and the other leader of the project.
"We can take the orbits of comets currently known and use a computer to calculate the times when those comets would be visible in the skies during the Middle Ages," Lacerda told Live Science. "The precise times depend on whether our computer simulations include Planet Nine. So, in simple terms, we can use the medieval comet sightings to check which computer simulations work best: the ones that include Planet Nine or the ones that do not."
(Excerpt) Read more at livescience.com ...
For some time now, I've attributed the wobble in the ephemeri to an unexplained planetary body moving either in retrograde or more or less perpendicular to the ecliptic. Analogously, that's a description of Jupiter's moon system.
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By a coincidence, I've got the Canterbury episode of Time Team streaming in the other room.
Weekly digest ping, and to all on both lists (and all who read this topic), hope you have a great weekend.
There’s an equation which relates the period of a planet to its distance from the Sun.
Period squared = distance cubed
(where distance is the average distance from the Sun).
For example, Jupiter has a period of 11.86 years, and an average distance from the Sun of 5.1 a.u. (astronomical units, the distance of earth from the Sun).
So 11.86 squared = 5.1 cubed.
For Neptune, it’s 165 (years) squared and 30 (a.u.) cubed.
This planet that is supposed to be ten times as far from the Sun as Neptune is 300 a.u. from the Sun. Cube that and you get 27,000,000. The square root of 27 million is about 5,200. So the period of this planet would be 5,200 years.
“11.86 squared = 5.1 cubed”
Uh, no it doesn’t. Sounds like something analogous to so-called Bode’s Law, which is really just Bode’s mnemonic.
Sounds more like “Plan IX from Outer Space”.
“they explored past the dust cloud and saw the rest of the Universe, immediately taking a disliking to it and determining it must go.”
What came to mind.
Of course you’d have to accurately compensate for changes in the calendar over the intervening ages. Doesn’t sound very ‘precise’ to me.
Lol! I think it makes life more interesting. What I read is much more fun than what’s actually printed. I think it’s a function of skimming things to get to the stuff you really want to read.
Yep, the true perspective is hard to visualize when it’s all on one page. I was actually watching something about Planet 9 yesterday. They put it in this perspective... If the sun was the size of a basketball, We would be looking for planet 9 at a distance of 18 miles away and it would be the size of an airsoft pellet.
Ultima Thule
Discovered June 26, 2014
New Horizons FlyBy January 1 2019
Distance from Earth 4 billion miles
Eris is about the same size as Pluto. At the time it was discovered, Pluto was considered a planet. Hence, Eris would be a planet, too. But instead of announcing that they had found a tenth planet, astronomers FIRST voted to change the classification of Pluto THEN announce that they had discovered Eris, by which time they had also discovered Haumea. So there were never big headlines; Eris would be covered like just another asteroid.
Eris was not the explanation for what made some astronomers look for a tenth planet, but that has nothing to do with whether or not it was a tenth planet.
Incidentally, the definition of a planet used to deny Eris and Pluto are planets is ridiculous. It’s very complicated and yet useless as a universal standard for looking beyond our own solar system. A much simpler one would be that any object which is sufficiently large enough to be round to due hydrostatic equilibrium and which revolves directly a primary star is a planet. The complication for that standard is works great for rocky planets, not so great for snowballs.
LOL
LOL
Uh-oh, that looks like it's going to turn into a flaming globe of Sigmund.
And yet, astronomers discovered the first planet since ancient times, telescopically, 200 years ago, and have been finding planets in orbit around other stars for the past 20 or so years. Realizing the scale of the universe makes those discoveries even more impressive. :^)
We remain driven by high improbability. :^)
Of course it's precise -- the dates when the calendar was adjusted are known with precision.
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