Of the more than 600,000 known asteroids in our Solar System, almost 10 000 are known as Near-Earth Objects (NEOs). These are asteroids or comets whose orbits bring them close to Earth’s, and which could potentially collide with us at some point in the future. As such, monitoring these objects is a vital part of NASA’s ongoing efforts in space. One such mission is NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE), which has been active since December 2013.
And now, after two years of study, the information gathered by the mission is being released to the public. This included, most recently, NEOWISE’s second year of survey data, which accounted for 72 previously unknown objects that orbit near to our planet. Of these, eight were classified as potentially hazardous asteroids (PHAs), based on their size and how closely their orbits approach Earth.
Originally launched back in 2009 as the Wide-field Survey Explorer (WISE), the spacecraft relied on its infrared telescope to look for previously undetected star clusters and main belt asteroids. In February of 2011, the mission ended and the spacecraft was put into hibernation. As of December 2013, it was reactivated for the purpose of surveying Near-Earth Objects (i.e. comets and asteroids) for the remainder of its service life.