Category: Space & Time

Here you will find all articles published in the Space & Time category.

Earth

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Earth is the largest terrestrial planet in the Solar System, the third planet from the Sun and the only astronomical object known to sustain life. It has a mean radius of ~ 6371 km, a mean distance to the Sun of ~ 150 million km and an orbital period of ~ 365 days. Earth is thought to have formed approximately 4.55 billion years ago and has one natural satellite, the Moon. The planet has a differentiated structure consisting of a crust, mantle and core and features plate tectonics. Importantly, Earth harbors abundant liquid water at its surface, most of which can be found in its oceans. The planet is surrounded by an atmosphere that contains ~ 78 % nitrogen (N2), ~ 21 % oxygen (O2) and several other trace gases, including carbon dioxide (CO2) and water vapor (H2O).

Information source: NASA

Image: Earth as seen from space, also known as the Blue Marble. Credit: NASA/NOAA/Reto Stöckli.

Pillars of Creation

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The Pillars of Creation are pillars of interstellar gas and dust in the Eagle Nebula, ~ 5 lightyears tall and at a distance of ~ 7000 lightyears from the Earth. Massive new stars are being formed within the pillars, but at the same time the gas and dust are being eroded by the intense ultraviolet light from nearby young stars. The different colors in the Pillars of Creation result from the electromagnetic emission from different elements: blue is related to oxygen, orange is related to sulfur and green is related to both hydrogen and nitrogen.

Information source: NASA

Image: The Pillars of Creation in the Eagle Nebula as seen from the Hubble Space Telescope. Source: NASA/ESA/Hubble Heritage Team.

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