[meteorite-list] Secondhand Spacecraft Has Firsthand Asteroid Experience (NEOWISE)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 11 Nov 2015 12:13:49 -0800 (PST)
Message-ID: <201511112013.tABKDnTG015856_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4767

Secondhand Spacecraft Has Firsthand Asteroid Experience
Jet Propulsoin Laboratory
November 11, 2015

The NEOWISE mission hunts for near-Earth objects (NEOs) using the Wide-field
Infrared Survey Explorer (WISE) spacecraft. Funded by NASA's NEO Observations
Program, the NEOWISE mission uses images taken by the spacecraft to look
for asteroids and comets, providing a rich source of measurements of solar
system objects at infrared wavelengths. These measurements include wavelengths
that are difficult or impossible to detect directly from the ground.

NEOWISE is one of 54 ongoing projects supported by the NEO Observations
Program in fiscal year 2015. NASA-funded survey projects have found 98
percent of the known catalogue of more than 13,000 NEOs. NASA-funded surveys
are currently finding NEOs at a rate of about 1,500 per year.

The NEOWISE mission uses a repurposed NASA spacecraft to find and characterize
asteroids. Launched in December 2009, WISE was tasked with documenting
in infrared light some of the most remote objects in not only our galaxy,
but our universe. Less than two years later, WISE had done just that,
scanning the entire sky not once, but twice. From galaxies, to stars,
to black holes, WISE collected data on over 750 million celestial targets
of interest. With its mission a complete success after a year of operations,
WISE was put into hibernation. In December 2014, the space telescope was
revived with an updated mission and a new name. Its job was to find and
collect the infrared signatures on some of our closest celestial neighbors
- asteroids, comets and near-Earth objects. Now led by Principal Investigator
Amy Mainzer of NASA's Jet Propulsion Laboratory in Pasadena, Calif., the
mission was named Near-Earth Object WISE, or NEOWISE.

As an infrared telescope, NEOWISE sees the heat emitted from celestial
bodies. Although it's common to think of objects in space as very cold,
our sun warms the surfaces of asteroids, making them glow brightly in
NEOWISE images. Even asteroids as dark as black ink, which can be difficult
to see against the darkness of space in visible wavelengths, can be spotted
by NEOWISE's camera.

"Using visible wavelengths of light, it is difficult to tell if an asteroid
is big and dark, or bright and small, because both combinations reflect
the same amount of light," said Carrie Nugent, a NEOWISE scientist at
the Infrared Processing and Analysis Center at California Institute of
Technology, in Pasadena. "But when you look at an asteroid in the infrared
with NEOWISE, the amount of infrared light corresponds with how big the
asteroid is, and with some thermal models on a computer, you can figure
out how big the asteroids are."

With these thermal models, the NEOWISE team has measured the size and
brightness of about 20 percent of the known asteroid population. In the
first year since reactivation, Nugent and the NEOWISE team have made these
measurements for almost 8,000 asteroids, including 201 near-Earth asteroids.

"When WISE rolled off the assembly line, it was like a shiny new car with
all the latest technology," said Nugent. "Now it's like that first car
you get out of school -- more vintage than new and with a lot of miles
on the odometer. But NEOWISE is giving us great data and experience behind
the wheel and reminding us every day how powerful infrared space telescopes
are for finding and studying asteroids."

NEOWISE snaps an infrared image of the sky every 11 seconds from its orbit
around Earth. Outside of Earth's atmosphere, it always has a clear view
of the night sky. NEOWISE's orbit was designed so that the telescope never
sees the sun. Although a person may not like the idea of living in darkness,
this is perfect for NEOWISE, since too much light would damage its sensitive
sensors.

Although NEOWISE has been a reliable workhorse operating long past its
planned lifetime, its mission will eventually come to an end. The spacecraft's
orbit is changing, and sometime in 2017, engineers estimate it will move
into too much sunlight to function. However, the team is eyeing a new
space telescope, one with a little more muscle. NEOWISE Principal Investigator
Amy Mainzer led a proposal for a new asteroid-hunting spacecraft, the
Near-Earth Object Camera (NEOCam). Unlike NEOWISE, NEOCam is specifically
designed to hunt asteroids. NEOCam is one of five Discovery-class proposals
funded for further study this year by NASA.

"There's so much left to discover when it comes to asteroids," said Nugent.
"And the NEOWISE mission is a great asset for learning more about our
closest extraterrestrial neighbors."

More information about the NEOWISE mission is at:

http://neowise.ipac.caltech.edu/

More information about the NEOCam proposal is at:

http://neocam.ipac.caltech.edu/


Media Contact

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle at jpl.nasa.gov

2015-344
Received on Wed 11 Nov 2015 03:13:49 PM PST