[{"date":"2006-09-27","explanation":"What's that pale blue dot in this image taken from Saturn?  Earth.  The robotic Cassini spacecraft looked back toward its old home world earlier this month as it orbited Saturn.  Using Saturn itself to block the bright Sun, Cassini imaged a faint dot on the right of the above photograph.  That dot is expanded on the image inset, where a slight elongation in the direction of Earth's Moon is visible.  Vast water oceans make Earth's reflection of sunlight somewhat blue.  Earth is home to over six billion humans and over one octillion Prochlorococcus.","hdurl":"https://apod.nasa.gov/apod/image/0609/earth2_cassini.jpg","media_type":"image","service_version":"v1","title":"Earth from Saturn","url":"https://apod.nasa.gov/apod/image/0609/earth2_cassini_big.jpg"},{"date":"2000-11-09","explanation":"rly on, x-ray satellites revealed a surprising cosmic background glow of x-rays and astronomers have struggled to understand its origin. Now, peering through a hole in the obscuring gas and dust of our own Milky Way Galaxy, the powerful orbiting XMM-Newton telescope has recorded this deep image of the x-ray sky, resolving some of the mysterious background into many faint individual sources. The tantalizing image is color-coded, with red representing relatively low energy x-rays, photons with 500 or so times the energy of visible light. Green and blue colors correspond to increasingly energetic x-rays with up to about 10,000 times visible light energies. Notably, the faint sources tend to be green and blue, showing x-ray characteristics of huge amounts of material falling into massive black holes in very distant galaxies. Do massive black holes reside in the hearts of all large galaxies? The XMM-Newton results add to the growing consensus that they do and that, from across the universe, x-rays produced as matter feeds these black holes account for the cosmic x-ray background.","hdurl":"https://apod.nasa.gov/apod/image/0011/lockman_xmm.jpg","media_type":"image","service_version":"v1","title":"The Cosmic X-Ray Background","url":"https://apod.nasa.gov/apod/image/0011/lockman_xmm.jpg"}]