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"I want to know why the universe exist, why there is something greater than nothing."
Steven Hawking
Scientist, Space Lover
Only 11 million light-years away, Centaurus A is the closest active galaxy to planet Earth. Spanning over 60,000 light-years, the peculiar elliptical galaxy, also known as NGC 5128, is featured in this sharp color image. Centaurus A is apparently the result of a collision of two otherwise normal galaxies resulting in a fantastic jumble of star clusters and imposing dark dust lanes. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. As in other active galaxies, that process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A.
Here are the true colors of planet Earth. Blue oceans dominate our world, while areas of green forest, brown mountains, tan desert, and white ice are also prominent. Oceans appear blue not only because water itself is blue but also because seawater frequently scatters light from a blue sky. Forests appear green because they contain chlorophyll, a pigment that preferentially absorbs red light. The above image is a composite generated predominantly with data from Moderate Resolution Imaging Spectroradiometer (MODIS), an instrument mounted on the Terra satellite that has orbited Earth since 1999 December. Sub-areas were imaged only when experiencing cloud-free daylight when it occurred from June through September 2001. The Earth looks much different at night.
Why does this galaxy emit such spectacular jets? No one is sure, but it is likely related to an active supermassive black hole at its center. The galaxy at the image center, Hercules A, appears to be a relatively normal elliptical galaxy in visible light. When imaged in radio waves, however, tremendous plasma jets over one million light years long appear. Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center. Pictured above is a visible light image obtained by the Earth-orbiting Hubble Space Telescope superposed with a radio image taken by the recently upgraded Very Large Array (VLA) of radio telescopes in New Mexico, USA. The physics that creates the jets remains a topic of research with a likely energy source being infalling matter swirling toward the central black hole. Follow APOD on: Facebook (Daily) (Sky) (Spanish) or Google Plus (Daily) (River)
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