NASA's Mars Exploration Rover Opportunity caught an image of a celestial visitor -- comet C/2013 A1 Siding Spring -- as the comet approached near to Mars on Oct. 19, 2014.
› Read more (October 20, 2014)
Rosetta's Comet Landing Site Close Up
An annotated mosaic from the Rosetta spacecraft shows "Site J," the primary landing site on comet 67P/Churyumov-Gerasimenko for the mission's Philae lander.
› Read more (October 15, 2014)
Rosetta Selflessly Beams Back Comet Selfie
A composite image from a camera on the Rosetta mission's Philae comet lander shows a solar array, with comet 67P/Churyumov-Gerasimenko in the background.
› Read more (October 14, 2014)
NASA Prepares its Science Fleet for Oct. 19 Mars Comet Encounter
NASA's extensive fleet of science assets, particularly those orbiting and roving Mars, have front row seats to image and study a once-in-a-lifetime comet flyby on Sunday, Oct. 19.
› Read more (October 09, 2014)
Average distance between Earth and the moon is about 239,000 miles (385,000 kilometers).
The Asteroid Watch Widget tracks asteroids and comets that will make relatively close approaches to Earth. The Widget displays the date of closest approach, approximate object diameter, relative size and distance from Earth for each encounter. The object's name is displayed by hovering over its encounter date. Clicking on the encounter date will display a Web page with details about that object.
The Widget displays the next five Earth approaches to within 4.6 million miles (7.5 million kilometers or 19.5 times the distance to the moon); an object larger than about 150 meters that can approach the Earth to within this distance is termed a potentially hazardous object.