[{"date":"2005-05-08","explanation":"Our Earth is not at rest.  The Earth moves around the Sun.  The Sun orbits the center of the Milky Way Galaxy.  The Milky Way Galaxy orbits in the Local Group of Galaxies.  The Local Group falls toward the Virgo Cluster of Galaxies.  But these speeds are less than the speed that all of these objects together move relative to the cosmic microwave background radiation (CMBR).  In the above all-sky map, radiation in the Earth's direction of motion appears blueshifted and hence hotter, while radiation on the opposite side of the sky is redshifted and colder.  The map indicates that the Local Group moves at about 600 kilometers per second relative to this primordial radiation.  This high speed was initially unexpected and its magnitude is still unexplained.  Why are we moving so fast?  What is out there?","hdurl":"https://apod.nasa.gov/apod/image/0302/dip_cobe.gif","media_type":"image","service_version":"v1","title":"CMBR Dipole: Speeding Through the Universe","url":"https://apod.nasa.gov/apod/image/0302/dip_cobe_big.jpg"},{"copyright":"Adam Block","date":"2005-04-06","explanation":"M7 is one of the most prominent open clusters of stars on the sky.  The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of Scorpius.  M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1000 light-years away.   This color picture was taken recently at the Kitt Peak National Observatory in Arizona, USA as part of the Advanced Observers Program. The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD.  Also visible is a dark dust cloud near the bottom of the frame, and literally millions of unrelated stars towards the Galactic center.","hdurl":"https://apod.nasa.gov/apod/image/0504/m7_cook_big.jpg","media_type":"image","service_version":"v1","title":"The M7 Open Star Cluster in Scorpius","url":"https://apod.nasa.gov/apod/image/0504/m7_cook.jpg"}]