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The Universe

Universe NASA-HS201427a-HubbleUltraDeepField2014-20140603.jpg The Hubble Ultra-Deep Field image shows some of the most remote galaxies visible with present technology, each consisting of billions of stars. (Apparent image area about 1/79 that of a full moon)[1] Age (within Lambda-CDM model) 13.799 ± 0.021 billion years[2] Diameter Unknown.[3] Diameter of the observable universe: 8.8×1026 m (28.5 Gpc or 93 Gly)[4] Mass (ordinary matter) At least 1053 kg[5] Average density (including the contribution from energy) 9.9 x 10?30 g/cm3[6] Average temperature 2.72548 K[7] Main contents Ordinary (baryonic) matter (4.9%) Dark matter (26.8%) Dark energy (68.3%)[8] Shape Flat with only a 0.4% margin of error[9] The Universe is all of space and time[a] and their contents,[10] including planets, stars, galaxies, and all other forms of matter and energy. While the spatial size of the entire Universe is unknown,[3] it is possible to measure the observable universe.

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