Alpha Centauri 2

Community => Recreation Commons => Destination: Alpha Centauri => Topic started by: Buster's Uncle on March 17, 2014, 10:17:39 pm

Title: New maps show smallest planet Mercury is even smaller
Post by: Buster's Uncle on March 17, 2014, 10:17:39 pm

New maps show smallest planet Mercury is even smaller
Reuters
By Irene Klotz  22 hours ago



CAPE CANAVERAL, Florida (Reuters) - Detailed maps of Mercury's cliffs and ditches show the solar system's innermost and smallest planet Mercury has lost much more real estate due to cooling over four billion years than scientists thought, according to a report published on Sunday.

Cooling of Mercury's massive iron core has pared about nine miles from the planet's diameter, more than twice as much as previous estimates.

"When you look at the actual number, it's really pityingly small, compared to the size of a planet. But it doesn't need to change very much to have some effect," said planetary scientist Paul Byrne, with the Carnegie Institution's Department of Terrestrial Magnetism.

Scientists studied more than 5,900 surface features, including cliff-like scarps and wrinkle ridges, to calculate how much Mercury has condensed.

Unlike Earth, which as several plates of crust, Mercury has just one rigid, rocky layer which bears telltale cliffs and chasms caused by global contraction.

The measurements, made with NASA's Mercury-orbiting MESSENGER spacecraft, match computer model predictions, which scientists use to determine the planet's inner composition, chemistry and structure.

"An awful lot of a planet's processes are driven by its heat loss - that's a primary thing that drives a planet's evolution," Byrne said. "We didn't set out to prove the models right, but it turns out this number is exactly what the models have been predicting for 40 years."

Previous maps of Mercury's surface map date back to the mid-1970s. NASA's Mariner 10 spacecraft made three flybys of the planet, imaging about 45 percent of its surface.

That data indicated Mercury had lost 1.2 to 3 miles in diameter, a finding that clashed with scientists' heat dissipation models for the planet.

In addition to learning more about how Mercury evolved, the discovery has implications for assessing the compositions of planets beyond the solar system.

"It may be that Mercury is an archetypal example of what a planet does and how it behaves as it has cooled in time," Byrne said.

The research is published in the journal Nature Geoscience.


http://news.yahoo.com/maps-show-smallest-planet-mercury-even-smaller-231841698.html (http://news.yahoo.com/maps-show-smallest-planet-mercury-even-smaller-231841698.html)

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: gwillybj on March 18, 2014, 02:43:41 am

I hope it doesn't shrink much more; they'll stop calling it a planet. ;sarc

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Geo on March 18, 2014, 03:40:09 pm

Just call it a moon of the sun then. ;nod

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Valka on April 01, 2014, 09:48:33 pm

Seems rather unfair that this little pipsqueak gets to be a planet, and Pluto - with FIVE moons of its own - doesn't.

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Buster's Uncle on April 01, 2014, 09:49:57 pm

They can't handle the non-ecliptic orbit...

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Valka on April 01, 2014, 09:58:46 pm

That's orbital discrimination!

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Geo on April 01, 2014, 09:59:29 pm

Quote from: Valka on April 01, 2014, 09:48:33 pm

Seems rather unfair that this little pipsqueak gets to be a planet, and Pluto - with FIVE moons of its own - doesn't.

This little 'pipsqueak' is still over twice the diameter of that Pluto dwarf! ;lol
Furthermore, the 3 smaller moons are thought to be collision remnants from when the Pluto-Charon pair formed.
But we'll just have to wait for next year when the Pluto probe passes the system. Who knows what it will discover/confirm.

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Geo on April 01, 2014, 10:01:09 pm

Quote from: BUncle on April 01, 2014, 09:49:57 pm

They can't handle the non-ecliptic orbit...

Mercury has the most extreme ecliptic orbit of all the planets.

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Buster's Uncle on April 01, 2014, 10:28:15 pm

Plane of the ecliptic.

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Geo on April 02, 2014, 03:19:51 am

Do keep in mind English isn't my native language. :P

Title: Re: New maps show smallest planet Mercury is even smaller
Post by: Buster's Uncle on April 02, 2014, 03:21:13 am

Yes, I never forget that you're only a Flem.



Hey, I bet you've never seen the Monty Python 'Prejudice' skit, unless Maniac showed you.   Heheheheh...