Search results
Results from the WOW.Com Content Network
Mercury, being the closest to the Sun, with a weak magnetic field and the smallest mass of the recognized terrestrial planets, has a very tenuous and highly variable atmosphere (surface-bound exosphere) containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, with a combined pressure level of about 10 −14 bar (1 nPa). [2]
Several areas on Mercury are extremely dark, such as a small crater within Hemingway crater in the lower right. The geology of Mercury is the scientific study of the surface, crust, and interior of the planet Mercury. It emphasizes the composition, structure, history, and physical processes that shape the planet.
Before 1974, it was thought that Mercury could not generate a magnetic field because of its relatively small diameter and lack of an atmosphere. However, when Mariner 10 made a fly-by of Mercury (somewhere around April 1974), it detected a magnetic field that was about 1/100 the total magnitude of Earth's magnetic field.
Mercury received impacts over its entire surface during this period of intense crater formation, [52] facilitated by the lack of any atmosphere to slow impactors down. [57] During this time Mercury was volcanically active; basins were filled by magma, producing smooth plains similar to the maria found on the Moon.
Scientists have found a new Earth-like planet that could support alien life – just 40 light-years away.. The planet is a remarkable discovery in the search for habitable worlds: it is slightly ...
Venusian craters range from 3 kilometres (2 mi) to 280 kilometres (174 mi) in diameter. There are no craters smaller than 3 km, because of the effects of the dense atmosphere on incoming objects. Objects with less than a certain kinetic energy are slowed down so much by the atmosphere that they do not create an impact crater. [17]
For example, Mercury does not have an atmosphere because it is so close to the sun that the solar winds have stripped it from the planet. Earth has an atmosphere largely because of the magnetic field which deflects most of the harmful radiation and solar winds away from the surface.
It happens because of something called the Rayleigh effect, or Rayleigh scattering, named after a British scientist who first wrote about it in 1871. Bands of vivid blue, pink and orange light are ...