planet earth, saturn and jupiter in a cosmic cloud - Elements of this image furnished by NASA

The Outer Region of the Solar System

June 13, 2020

The Solar System is divided into the inner and outer regions, grouping similar planets together. The outer region of the solar system hosts the gas giants: Jupiter, Saturn, Uranus, and Neptune. However, the system continues far beyond Neptune. The comets, for instance, come from the far end, but how far? […]

Watercolor universe Sky, stars, deep space Violet, blue, fantasy background

Ice in the Solar System: From Lakes to Comets

June 13, 2020

Ice in the Solar System includes of various types and materials: from ice giants to the water ice particles orbiting Saturn, to the type that is found on comets. The existence of ice in some places indicates the existence of water. Read more to know if planets have oceans of water. […]

Solar system planet, comet, sun and star.

Terrestrial Planets: The Inner Region of the Solar System

June 12, 2020

Terrestrial planets are the ones in the inner region of the Solar System, with hard surfaces, heavy-metal liquid cores, moons, rocks, valleys, volcanoes, and ice. Their distance to the Sun, the heaviest member of the System, has caused these features. […]

Artist's impression of a time loop. Closed timelike curves allow a material particle to traverse spacetime and return to its starting point.
History of Science

Do Closed Timelike Curves Exist or Not?

May 15, 2020

A number of solutions to the field equations have shown that closed timelike curves can exist. However, there’s still uncertainty regarding the existence of closed timelike curves. Why is this the case? […]

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