Great bit of news. NASA’s recently re-awakened Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) rubbed the sleep from its eyes and promptly discovered a new comet. The Earth-orbiting telescope snagged C/2014 C3 (NEOWISE) on Valentine’s Day when it was about 143 million miles (230 million km) from Earth. Although the comet’s orbit isn’t precisely determined, it appears to originate from the realm of the distant planets Uranus and Neptune.
Originally called the Wide-field Infrared Survey Explorer (WISE), its primary mission wrapped up in 2011 after two very successful years. WISE performed an all-sky survey in infrared light (heat) that uncovered tens of thousands of new asteroids, luminous, star-burst galaxies and dim brown dwarfs. Along the way it also added 21 new comets to its booty.
Our eyes can’t see infrared, but we sense it as heat. The probe’s 15.7-inch (0.4-m) telescope is optimized for just that very slice of the spectrum. Infrared light penetrates dust clouds revealing what’s inside (newborn stars for instance) and can see otherwise faint, dark asteroids by the heat they radiate into space.
Two years later in September 2013 WISE was taken out of hibernation and re-activated as NEOWISE to assist NASA’s efforts to identify the population of potentially hazardous near-Earth objects. It will also study previously known asteroids and comets to better understand their sizes and compositions.
Wondering what’s going on with comets you and I might see in our telescopes? Comet ISON has long gone to comet heaven. And three other bright comets – Lovejoy, Encke and C/2012 X1 LINEAR - that kept us from our sleep so many nights have either faded from view or lost their luster. Morning skywatchers using 6-inch or larger telescopes can still follow Lovejoy and X1 LINEAR, both glowing around magnitude 9, but it’s slim pickings otherwise.
Sit tight. Come late summer we’ll have several nice binocular comets from which to choose.