Which of these gives out its own heat and light?
2 Mars at 54 Million Miles from Earth, NASA Hubble Space Telescope, NASA, CC BY 2.0 DEED, 4 Earthstar Geographics, Source: Airbus,USGS,NGA,NASA,NOAA,GEBCO,CGIAR,NLS,OS,NMA,Geodatastyrelsen,GSA,GSI and the GIS User Community
