A Sense of Doubt blog post #1246 - Twelve new Jovian Moons - Two to Crash

 Nasa photograph showing two of Jupiter’s 79 moons. Photograph: JPL/NASA

A Sense of Doubt blog post #1246 - Twelve new Jovian Moons - Two to Crash

As you know, I like space, unless you didn't know, and now you do.

I have a category for space posts. That's how much I like it.

This article caught my eye.

PS: The Guardian NEEDS donations.

Oh, and two videos!

https://www.theguardian.com/science/2018/jul/17/astronomers-discover-12-new-moons-orbiting-jupiter

Astronomers discover 12 new moons orbiting Jupiter - one on collision course with the others

A head-on collision between two Jovian moons would create a crash so large it would be visible from earth

One of a dozen new moons discovered around Jupiter is circling the planet on a suicide orbit that will inevitably lead to its violent destruction, astronomers say.

Researchers in the US stumbled upon the new moons while hunting for a mysterious ninth planet that is postulated to lurk far beyond the orbit of Neptune, the most distant planet in the solar system.

The team first glimpsed the moons in March last year from the Cerro Tololo Inter-American Observatory in Chile, but needed more than a year to confirm that the bodies were locked in orbit around the gas giant. “It was a long process,” said Scott Sheppard, who led the effort at the Carnegie Institution for Science in Washington DC.

Jupiter, the largest planet in the solar system, was hardly short of moons before the latest findings. The fresh haul of natural satellites brings the total number of Jovian moons to 79, more than are known to circle any other planet in our cosmic neighbourhood.

 Astronomers have discovered twelve new moons orbiting Jupiter, bringing the total number of Jovian moons to 79. Photograph: Carnegie Institution for Science

Nine of the new moons belong to an outer group that orbit Jupiter in retrograde, meaning they travel in the opposite direction to the planet’s spin. They are thought to be the remnants of larger parent bodies that were broken apart in collisions with asteroids, comets and other moons. Each takes about two years to circle the planet.

Two more of the moons are in a group that circle much closer to the planet in prograde orbits which travel in the same direction as Jupiter’s spin. Most likely to be pieces of a once larger moon that was broken up in orbit, they take nearly a year to complete a lap around Jupiter. Which direction the moons swing around the planet depends on how they were first captured by Jupiter’s gravitational field.

Astronomers describe the twelfth new Jovian moon as an “oddball”. Less than a kilometre wide, the tiny body circles Jupiter on a prograde orbit but at a distance that means it crosses the path of other moons hurtling towards it. Scientists have named the new moon Valetudo after the Roman god Jupiter’s great-granddaughter, the goddess of health and hygiene. But given the impending violence, it may be more than coincidence that Vale Tudo, which translates from Portuguese as “anything goes”, is an early form of full-contact mixed martial arts. 

“Valetudo is like driving down the highway on the wrong side of the road,” said Sheppard. “It is moving prograde while all the other objects at a similar distance from Jupiter are moving retrograde. Thus head-on collisions are likely.”

Sheppard, whose report appears in the International Astronomical Union Minor Planet Electronic Circular, suspects that Valetudo is the final remnant of a once much larger moon that has been ground to dust by collisions in the past.

Which raises the question of how long the tiny moon has left. “Collisions don’t happen all that frequently, every billion years or so,” said Sheppard. “If one did happen, we would be able to detect it from Earth, but it is unlikely to happen anytime soon.”

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- Bloggery committed by chris tower - 1807.20 - 10:10

- Days ago = 1112 days ago

- New note - On 1807.06, I ceased daily transmission of my Hey Mom feature after three years of daily conversations. I plan to continue Hey Mom posts at least twice per week but will continue to post the days since ("Days Ago") count on my blog each day. The blog entry numbering in the title has changed to reflect total Sense of Doubt posts since I began the blog on 0705.04, which include Hey Mom posts, Daily Bowie posts, and Sense of Doubt posts. Hey Mom posts will still be numbered sequentially. New Hey Mom posts will use the same format as all the other Hey Mom posts; all other posts will feature this format seen here.