Search results
Results From The WOW.Com Content Network
The Sun is composed primarily of the chemical elements hydrogen and helium; they account for 74.9% and 23.8%, respectively, of the mass of the Sun in the photosphere.All heavier elements, colloquially called metals in stellar astronomy, account for less than 2% of the mass, with oxygen (roughly 1% of the Sun's mass), carbon (0.3%), neon (0.2%), and iron (0.2%) being the most abundant.
Other layers break up into large boulders so they are probably much harder. Basalt, a volcanic rock, is thought to in the layers that form boulders. Basalt has been identified on Mars in many places. Instruments on orbiting spacecraft have detected clay (also called phyllosilicate) in some layers.
If placed on Earth, Valles Marineris would span the width of North America. [36] In places, the canyons are up to 300 km wide and 10 km deep. Often compared to Earth's Grand Canyon, the Valles Marineris has a very different origin than its tinier, so-called counterpart on Earth. The Grand Canyon is largely a product of water erosion.
Like Earth, Mars is differentiated into a dense metallic core overlaid by less dense rocky layers. [ 45 ] [ 46 ] The outermost layer is the crust, which is on average about 42–56 kilometres (26–35 mi) thick, [ 47 ] with a minimum thickness of 6 kilometres (3.7 mi) in Isidis Planitia , and a maximum thickness of 117 kilometres (73 mi) in the ...
The spectrum of sunlight has approximately the spectrum of a black-body radiating at 5,772 K (9,930 °F), [12] interspersed with atomic absorption lines from the tenuous layers above the photosphere. The photosphere has a particle density of ~10 23 m −3 (about 0.37% of the particle number per volume of Earth's atmosphere at sea level). The ...
The red color of the chromosphere could be seen during the solar eclipse of August 11, 1999.. The density of the Sun's chromosphere decreases exponentially with distance from the center of the Sun by a factor of roughly 10 million, from about 2 × 10 −4 kg/m 3 at the chromosphere's inner boundary to under 1.6 × 10 −11 kg/m 3 at the outer boundary. [7]
This process, called hydrothermal alteration, is a major way in which ore deposits are produced. The area around Martian craters may be rich in useful ores for the future colonization of Mars. [63] Studies on Earth have documented that cracks are produced and that secondary minerals veins are deposited in the cracks.
A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. [2]