NRL telescope onboard ESA, NASA SOHO (IMAGE) Naval Research Laboratory Caption Courtesy Photo | The 4,000th comet discovered by ESA (European Space Agency) and NASA's SOHO observatory is seen here in an image from the spacecraft alongside SOHO's 3,999th comet discovery. The two comets are relatively close at approximately 1 million miles apart, suggesting that they could have been connected together as recently as a few years ago. Credit ESA/NASA/SOHO/Karl Battams Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.