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[NASA Image of the Day] Cosmic Microwave Background Dipole

Translated by DeepSeek V4 Pro. Translations can be inaccurate, please refer to the original post for important stuff.

Microwave Background Radiation, Copyright: DMR, COBE, NASA, Four-Year Sky Map

Explanation:
The Cosmic Microwave Background Dipole caused by Earth’s high-speed movement through the universe.

Our Earth is not stationary. The Earth orbits the Sun, the Sun orbits the center of the Milky Way, the Milky Way moves within the Local Group, and the Local Group is moving toward the Virgo Cluster. However, the speeds of these motions are all less than the speed at which these objects move relative to the Cosmic Microwave Background Radiation (CMBR). The image above is an all-sky map of the Cosmic Microwave Background Radiation captured by the COBE satellite. In the direction of Earth’s motion, the microwave background radiation appears blueshifted, meaning the cosmic background temperature appears higher. Conversely, in the opposite direction, the microwave background radiation appears redshifted, meaning the cosmic background temperature appears lower. This all-sky map shows that relative to this ancient radiation, the Local Group is moving at a speed of 600 kilometers per second. Such a high speed was unexpected, and even now, we cannot provide a reasonable explanation for the magnitude of this velocity. Why is the Local Group moving so fast? What objects out there are pulling us?

Translation from: http://www.skylook.org/apod/astropix.html

NASA URLs:
http://antwrp.gsfc.nasa.gov/apod/astropix.html

http://antwrp.gsfc.nasa.gov/apod/ap090906.html

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