Search results
Results from the WOW.Com Content Network
A planetary core consists of the innermost layers of a planet. [1] Cores may be entirely liquid, or a mixture of solid and liquid layers as is the case in the Earth. [ 2 ] In the Solar System , core sizes range from about 20% (the Moon ) to 85% of a planet's radius ( Mercury ).
Originally formulated by two independent research groups in 1976, the giant impact model supposed that a massive planetary object the size of Mars had collided with Earth early in its history. The impact would have melted Earth's crust, and the other planet's heavy core would have sunk inward and merged with Earth's.
Earth's inner core is the innermost geologic layer of the planet Earth. It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 20% of Earth's radius or 70% of the Moon's radius. [1] [2] There are no samples of the core accessible for direct measurement, as there are for Earth's mantle. [3]
In November 2010, it was announced that two large elliptical lobe structures of energetic plasma, termed bubbles, which emit gamma- and X-rays, were detected astride the Milky Way galaxy's core. [37] Termed Fermi or eRosita bubbles, [ 38 ] they extend up to about 25,000 light years above and below the Galactic Center. [ 37 ]
In planetary science, the term geology is used in its broadest sense, to mean the study of the surface and interior parts of planets and moons, from their core to their magnetosphere. The best-known research topics of planetary geology deal with the planetary bodies in the near vicinity of the Earth: the Moon , and the two neighboring planets ...
Its orbit revealed that it was a new planet, Uranus, the first ever discovered telescopically. [20] Giuseppe Piazzi discovered Ceres in 1801, a small world between Mars and Jupiter. It was considered another planet, but after subsequent discoveries of other small worlds in the same region, it and the others were eventually reclassified as ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The first successful planetary mission was the 1962 fly-by of Venus by Mariner 2. [180] The first fly-by of Mars was by Mariner 4 in 1964. Since that time, uncrewed spacecraft have successfully examined each of the Solar System's planets, as well their moons and many minor planets and comets.