Category: Space (page 7 of 9)

mercury’s surface

The surface of Mercury is different than that of other planets. It resembles the surface of a meteorite more than the surfaces of Earth or Mars for instance.  The Mercury Messenger probe has new data. Check the source link for a sample photograph:

Now, 205 measurements of Mercury’s surface composition, made by the X-ray spectrometer onboard Messenger, reveal how much Mercury’s surface differs from those of other planets in the solar system.

“Being the closest planet to the sun does mean its formation history would be different and more extreme than the other terrestrial planets, with hotter temperatures and exposure to a stronger gravitational field,” says lead study author Shoshana Weider, a planetary geologist at the Carnegie Institution of Washington.

The surface is dominated by minerals high in magnesium and enriched in sulfur, making it similar to partially melted versions of an enstatite chondrite, a rare type of meteorite that formed at high temperatures in low-oxygen conditions in the inner solar system.

“The similarity between the constituents of these meteorites and Mercury’s surface leads us to believe that either Mercury formed via the accretion of materials somewhat like the enstatite chondrites, or that both enstatite chondrites and the Mercury precursors were built from common ancestors,” Weider said.

More at Scientific American.

mars is the next frontier

Mars Insight

An artist’s render of the Mars InSight probe

The next mission to Mars includes plans to explore beneath the planet’s surface. The plan is called InSight and is scheduled for launch in 2016. The goal is to collect information on the crust, mantle and core of Mars to determine how the planet has evolved. This should enhance any knowledge that is gained from Curiosity’s surface exploration.

From Science:

 $425 million lander that would drill a few meters into Mars in order to probe its crust, mantle, and core will be NASA’s next major planetary science mission. In a teleconference late Monday, NASA’s associate administrator for the Science Mission Directorate, John Grunsfeld, announced that he has selected the InSight mission to Mars as NASA’s next cost-capped mission to explore the solar system. The craft will set a seismometer on the surface and send a temperature sensor down a drill hole to better understand how that rocky planet evolved from a nascent ball of magma.

InSight (Interior Exploration Using Seismic Investigations, Geodesy, and Heat Transport) beat out two other finalists for NASA’s Discovery Program award. One would have splashed a craft onto a lake of liquefied natural gas on Titan, and another would have touched down on an active comet. InSight team members, led by planetary scientist W. Bruce Banerdt of NASA’s Jet Propulsion Laboratory in Pasadena, California, had made a strong pitch for their mission quickly returning the maximum science for the buck. InSight is based on the lander and spacecraft design that successfully delivered the Phoenix lander to Mars, they noted, which reduces both cost and risk. And while seismological studies have detailed Earth’s interior, the interiors of the three other rocky planets—Mercury, Venus, and Mars—have remained largely unknown. Mars, they argued, is large enough to have separated into crust, rocky mantle, and metallic core, but it has not been so tectonically active that it erased the record of that evolution.

it snows dry ice on mars

Dry Ice Slabs

In Mars news that isn’t from curiosity, when it snows on Mars it’s CO2 falling from the skies instead of frozen water. From Popular Science:

Dry ice, which is frozen carbon dioxide rather than solidified water, requires temperatures dipping far below those experienced beneath Earth’s atmosphere–roughly 193 degrees below zero Fahrenheit, to be slightly more precise. Researchers had already firmly established that clouds of carbon dioxide exist in Mars’ southern polar region, and they had previously found carbon-dioxide ice in the polar caps at the Martian south pole. What they lacked was the mechanism by which this carbon dioxide moves between cloud and ice cap–via precipitation or simply freezing out at ground level, like frost. And that’s what they’ve now found, thanks to the MRO.

These observations have essentially confirmed three things. One, that carbon dioxide ice particles observed in these polar clouds are large enough to fall to the surface. Second, that these “flakes” of carbon dioxide ice could develop and fall to the ground during the lifespan of the clouds. And most importantly, the MRO has provided strong evidence that they do exactly that. By pointing the orbiter’s instruments at the horizon from an angle rather than straight down at the ground from above, they were able to observe the presence of these ice particles extending from the clouds to the surface.

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