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Planet Mercury Has Shrunk More Than Thought
sciencehabit writes "Measuring just 4880 kilometers across, Mercury is a small world. The planet became slightly smaller as its interior cooled, which caused Mercury to shrink, buckling its surface and creating numerous cliffs and ridges. Now, after studying 5934 of these features, researchers report online today in Nature Geoscience that Mercury's contraction was much greater than previously thought: During the past 4 billion years, the planet's diameter decreased by 7 to 14 kilometers. The greater estimate of shrinkage accords with models that predict how much a rocky planet should contract as its interior cools; the new work may also lend insight into the evolution of extrasolar planets that, like Mercury and unlike Earth, lack any moving continents."
Easy mistake to make.
Do we need to worry about our water being contaminated in the event any of part of Mercury makes it to Earth?
Only 14 kilometers diameter left ? Hardly a planet anymore.
It's the girth, not the length that matters.
The shrinkage of a body in response to cooling was experimentally derived by Dr. Costanza in the 90's.
Mercury is trying to tell all the other planets it's shrinkage but they know better.
Obligatory penis joke aside, I'm surprised to hear it has "cooled" with it's greatest distance from the Sun being a mere 69,816,900 km.
"If any question why we died, Tell them because our fathers lied."
...but Uranus is expanding!
Space is cold!
Mercury meets the definition of planet, why not call it one?
You're thinking of Pluto.
Isn't it common knowledge?
Earth is called a planet, yet it most certainly isn't one.
woosh!
Ball-shrivelingly cold, as it turns out.
You're thinking of Pluto.
No, Uranus.
That sucks.
Sucks so far
Earth is a toxic waste repository for the dominant invasive species.
Serious? Seriousness is well above my pay grade.
You mean Urrectum?
Maybe it's just cold... Or at least that's what I told her.
We need that planet hater from the planetarium who talks all dramatically on PBS with hi swishy washy science to delist this planet like the freak did with Pluto. Yeeeeehaaaaah! I forgot his name but most people did too.
You mean Urrectum?
"And I said, rectum? I damn near killed 'em!"
In other news, your mother's diameter has expanded by 2km.
That's the important question.
We don't want a repeat of the Pluto incident. The solar system is already 11% gone, who knows how much we'll lose.
It's a small world after all...
Never answer an anonymous letter. - Yogi Berra
I thought cold caused shrinkage.
The messanger itself didnt get the message about some recent pharmaceutical advances ...
4 billion years ago? Give me a break! Who provided the measurements?
It was in the pool!!!
So its average density must be high, and the number of pits and caves on its surface and the collapse features say that volitile elements have been cooked out of what is left. Maybe someone in the know can tell if there is much S on the surface.
I'm sure that long after we have looked at differentiated planetessimals from the asteroid belt for heavy metals, imagine finding double the reserves of rare Iron group metals, or many times the amount of Au, Pt, Zr, Rh, Pd, Ir, Ti, Zr, out there than on the earth's crust, or better rare earths, that Mercury might be a good place to prospect for refractory heavy metals, ones with high melting points. How Ironic that Hg is probably long cooked off the planet! It would be a tough place to work, though. Most places in the solar system that have metals would have to manufacture refined products out there to make it worthwhile to bring them to earth,