The thin dense crust of MercuryUsing data gathered by the MESSENGER spacecraft while it was in orbit around Mercury, scientists now estimate that the planet’s crust is thinner than previously believed, 16 miles thick rather than 22 miles.
The crust is also as dense as aluminum. It is also the thinnest crust, relative to the planet’s core, of any rocky planet in the solar system.
Mercury’s core is believed to occupy 60 percent of the planet’s entire volume. For comparison, Earth’s core takes up roughly 15 percent of its volume. Why is Mercury’s core so large?
“Maybe it formed closer to a normal planet and maybe a lot of the crust and mantle got stripped away by giant impacts,” Sori said. “Another idea is that maybe, when you’re forming so close to the sun, the solar winds blow away a lot of the rock and you get a large core size very early on. There’s not an answer that everyone agrees to yet.”
There appears to be a great deal of uncertainty to these conclusions, and I would not be surprised if these conclusions change with the arrival of more data.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Using data gathered by the MESSENGER spacecraft while it was in orbit around Mercury, scientists now estimate that the planet’s crust is thinner than previously believed, 16 miles thick rather than 22 miles.
The crust is also as dense as aluminum. It is also the thinnest crust, relative to the planet’s core, of any rocky planet in the solar system.
Mercury’s core is believed to occupy 60 percent of the planet’s entire volume. For comparison, Earth’s core takes up roughly 15 percent of its volume. Why is Mercury’s core so large?
“Maybe it formed closer to a normal planet and maybe a lot of the crust and mantle got stripped away by giant impacts,” Sori said. “Another idea is that maybe, when you’re forming so close to the sun, the solar winds blow away a lot of the rock and you get a large core size very early on. There’s not an answer that everyone agrees to yet.”
There appears to be a great deal of uncertainty to these conclusions, and I would not be surprised if these conclusions change with the arrival of more data.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Ah, yeah, more data. I had forgotten about BeppiColombo that is to be launched in October to November this year. ESA’s and JAXA’s joint Mercury orbiter. Or two orbiters actually, they build one each, which I think is how different space agencies should cooperate, as independently as possible. Taking seven years to get into orbit, but first flyby of Mercury in 2021.
TESS, InSight, Parker Solar probe, CHEOPS, BeppiColombo. Is this a record year for launching significant science missions?
I read that they planned to have a 45 kg lander on the BeppiColombo, that was canceled for budget reasons. With a seismometer and a mole drill. Too bad.