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The Near-Earth Object Wide-field Infrared Survey Explorer at IPAC |
The NEOWISE 2016 Data Release makes available the 3.4 and 4.6 μm (W1 and W2) Single-exposure images and extracted source information that were acquired between December 13, 2014 and December 13, 2015 UTC, the second year of survey operations of the Near-Earth Object Wide-field Infrared Survey Explorer Reactivation Mission (NEOWISE; Mainzer et al. 2014, ApJ, 792, 30). The second year NEOWISE data products are concatenated with those from the first year (originally released on March 26, 2015) into a single archive so that all data can be queried easily at one time.
NEOWISE utilizes the Wide-Field Infrared Explorer (WISE; Wright et al. 2010, AJ, 140, 1868) spacecraft that surveyed the entire sky in 2010 with a cryogenically cooled 40 cm telescope and four 1kx1k mid-infrared array detectors. WISE continued to survey for four months following the exhaustion of its solid hydrogen cryogen in September 2010 using its two short wavelength bands. After completing a survey of the inner main asteroid belt and a second coverage of the sky, WISE was placed into hibernation in February 2011.
The WISE spacecraft was brought out of hibernation in September 2013 and renamed NEOWISE with a mission to detect and characterize asteroids and comets, and to learn more about the population of near-Earth objects that could pose an impact hazard to the Earth. The spacecraft was returned to zenith pointing which enabled the telescope and focal plane to passively cool down to approximately 73 K. Survey operations were resumed on December 13, 2013 UTC with the W1 and W2 detectors operating at sensitivities near those of the original cryogenic survey. The first solar system moving object tracklet candidates were reported to the IAU Minor Planet Center on December 26, and tracklet deliveries continue to be made three times per week. As of mid-March, 2016, NEOWISE has made over 350,000 infrared measurements of approximately 19,000 different solar system objects.
The combined NEOWISE Data Release products from the first two years of survey operations include:
NEOWISE scanned the sky nearly four complete times during the first two years of survey operations, with six months separating survey passes. Twelve independent exposures are acquired at each point on the sky near the ecliptic plane during each survey epoch, and the number of samples increases towards the ecliptic poles. As illustrated in Figure 1, the NEOWISE 2016 Release brings the total number of independent observations near the ecliptic plane to ~48, increasing to over 11,000 observations very close to the ecliptic poles.
The NEOWISE Release Single-exposure data products are time-domain resources for extracting thermal flux and position measurements for NEOWISE moving object detections, as well as a precovery archive for solar system objects discovered after the NEOWISE observations. The NEOWISE products are also an archive for studying flux variability and proper motion of galactic and extragalactic objects. When combined from the Single-exposure data from the original WISE mission, the NEOWISE images and source detection database provide an archive that spans a six year baseline with six or seven separate epochs of observation.
The NEOWISE Reactivation Mission is funded by the NASA Planetary Science Division. Planetary science research using NEOWISE data is eligible for proposals to the NASA ROSES Solar System Workings and Planetary Data Archiving, Restoration and Tools Programs. Astrophysics reasearch using NEOWISE data is eligible for proposals to the NASA ROSES Astrophysics Data Analysis Program.
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| Figure 1 - NEOWISE Year 1+2 Depth-of-Coverage. Ecliptic Aitoff projection sky map showing the average number of individual Single-exposures within 12´ × 12´ spatial bins that are included in the NEOWISE data release. Colors encode different frame depths-of-coverage as specified by the legend on the bottom. The percentages of sky covered to various depths are given in the upper left. Approximately 10% of the sky bounded by ecliptic longitude ranges 107.5°<λ<126.1° and 281.4°<λ<299.2° was not observed during the first coverage epoch because of a safe hold event. |
"This publication makes use of data products from the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), which is a project of the Jet Propulsion Laboratory/California Institute of Technology. NEOWISE is funded by the National Aeronautics and Space Administration."
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