July Astronomy Notes from Around the Galaxy
Volcanism forged Mercury’s surface
Images provided by MESSENGER from its January 14 fly-by provide strong evidence that volcanoes played a critical role in forming Mercury’s surface, according to geologist James Head of Brown University in Providence, Rhode Island. The Caloris basin, with a diameter of 960 miles, is one of the solar system’s biggest impact craters. (TWO links below — Reuters story plus original and better article on Space.com.)
http://www.space.com/scienceastronomy/080703-mercury-messenger.htmlSpeaking of Mercury — The Last Thing They Expected to Find Was WATER!
Mercury’s exosphere (as it’s normally termed) is so thin that the MESSENGER [name of Mercury mission] can fly directly through it without burning up (though if it had been worried about burning it wouldn’t have flown to Mercury in the first place). On the way through its Fast Imaging Plasma Spectrometer detected an awful lot of rock elements, as you might expect, but also signals indicating water element groups. To the general reactions of “What the Hell?” “Check it AGAIN!” and eventually “Wow!” back at mission control.
One explanation for this momentous moisture is that charged hydrogen atoms from the solar wind (which constantly flays the surface) can combine with oxygen from the vaporized crust of the planet to form the essential H2O. Sun radiation combined with blasted rocks on another planet – it makes Evian look like tap water in a council flat.
Universe Sandbox — Kinda Like “Smashing Planets” Plus Astro ‘Aquarium’
Check out this cool program: you can smash planets together, introduce rogue stars, and build new worlds from spinning discs of debris. Fire a moon into a planet or destroy everything you’ve created with a super massive black hole. You can simulate and interact with:
Our solar system: the 8 planets,160+ moons, and hundreds of asteroids
Nearest 1000 stars to our Sun
Our local group of galaxies
An unlimited number of fictional scenarios
http://www.dailygalaxy.com/my_weblog/2008/07/universe-sandbo.htmlMoon Volcanoes Show Detectable Water
All previous studies on moon samples had a minimum moisture sensitivity of fifty parts per million; it turns out the precious water was hiding down at the forty-six per million mark. Analysing samples of volcanic glass beads with the new technique of Secondary Ion Mass Spectrometry (SIMS) the bashful water was finally detected.
The distribution of H20 in the samples is consistent with the original material being relatively rich in water, about as much as the Earth’s upper mantle, but the volcanic processes causing 95% of it to be lost.
http://www.dailygalaxy.com/my_weblog/2008/07/h20-detected-fr.htmlAre Jupiter’s Red Spots Under Siege?
The little red spot (LRS) was first identified by John Rogers, British Astronomical Association’s Jupiter Section director. As Rogers recounts, “This spot appeared last winter while Jupiter was hidden behind the Sun. I noticed it on March 1st in images taken by amateur astronomers Tomio Akutsu in the Philippines and Anthony Wesley in Australia. Such spots in the South Tropical Zone (STrZ) are very rare.”
Since LRS’s discovery, the currents of the STrZ have carried it inexorably toward the Great Red Spot. Jupiter watchers wondered what would happen to the small spot when it encountered the GRS and the adjacent Oval BA (Red Spot Junior). The moment of fate arrived on July 3rd, when the LRS tried to squeeze through the narrow gap between the GRS and adjacent Oval BA like dough through the rollers of a pasta machine.
As of this date, the little spot’s ultimate fate remains unclear.
Entry filed under: Astronomy Notes on the Web.