December 2018 Approach through the large, near-Earth asteroid 2003 from SD220
Astronomers have an excellent opportunity to get detailed radar images of the surface
and shape of the object and to improve understanding of its orbit.
The asteroid will be on Saturday, December 22, safely at a distance of approx
1.8 million miles (2.9 million kilometers).
That will be it
Asteroid's closest approach in more than 400 years and the next to 2070, when
the asteroid will surely approach the earth a little closer.
reveal radar images
an asteroid with a length of at least 1.6 km and a similar shape
to the exposed part of a hippopotamus wading in a river. They were received
at the Goldstone Deep Space Communications Complex in California's National Science Foundation
100-meter Green Bank Telescope in West Virginia and the Arecibo Observatory
305 meters antenna in Puerto Rico.
The Green Bank Telescope was the recipient of the strong microwave signals transmitted by Goldstone
or the NASA funded planetary radar Arecibo in a so-called "bistatic"
Radar configuration. "One telescope to send and another to receive
can be much more detailed than a telescope, and it is invaluable
Technique to obtain radar images of approaching slowly rotating asteroids
like this one.
Radar images reach an unprecedented level of detail and are therefore comparable
received from a spacecraft, "said Lance Benner from Jet Propulsion
Laboratory in Pasadena, California, and the scientist conducting the observations
from Goldstone. "The most striking surface feature is a distinctive ridge
that seems to wrap around the asteroid at one end. The ridge stretches
about 330 feet [100 meters] over the surrounding terrain. Numerous small bright ones
Spots are visible in the data and can be reflections of boulders. The pictures too
show a group of dark, circular elements on the right edge, which can be craters. "
Images confirm what has been seen in earlier "light curve" measurements
Sunlight reflected from the asteroid and earlier radar images of Arecibo: 2003
SD220 has an extremely slow rotation time of about 12 days. It has something too
seems to be a complex rotation that resembles badly thrown football. Known
as a "non-major axis" rotation, it is uncommon among near-Earth asteroids,
most rotate around their shortest axis.
Resolutions of up to 3.7 meters per pixel are the details of these images
20 times finer than the previous approach of the asteroid
to Earth three years ago, which was further away. The new radar data is displayed
Give important restrictions on the density distribution of the interior of the asteroid
– Information available on very few near-Earth asteroids.
With our knowledge of the slow rotation of the SD220 from 2003 we could plan this year
A large series of radar images using the largest single-dish radio telescopes
in the nation, "said Patrick Taylor, senior scientist at Universities Space
Research Association (USRA) at the Lunar and Planetary Institute (LPI) in
New details that we have discovered, down to the geology of the 2003 SD220, will allow this
We reconstruct their shape and their state of rotation, as is the case with Bennu, the goal of
OSIRIS REx mission, "said Edgard Rivera-Valentín, USRA scientist at LPI." detailed
The reconstruction of shapes helps us understand how these small bodies have formed
evolved over time. "
Taylor led the bistatic radar observations with the Green Bank Observatory, home of
the Green Bank Telescope, the world's largest fully deflectable radio telescope. Rivera-Valentín will lead the way
Reconstruction of 2003 SD220 and initiated the observations of the Arecibo Observatory.
2003 SD220 was discovered on September 29, 2003 by astronomers at the Lowell Observatory for Near Earth Objects (LONEOS)
Flagstaff, Arizona – an early exploration project near Earth (NEO)
from NASA, this is no longer in operation. It is classified
as a "potentially dangerous asteroid" because of its size and proximity
Approaches to the Earth's orbit. However, these radar measurements refine the
Understanding the orbit of SD220 from 2003 and confirmed that this is the case
no future impact on the earth.
The Arecibo, Goldstone and
USRA planetary radar projects are funded by NASA's Near-Earth Object Observations
Program within the Planetary Defense Coordination
Office (PDCO), which manages the agency
Planetary defense program. The Arecibo Observatory is a facility of the National
Scientific Foundation operated under the terms of a cooperation agreement by the University of Central
Florida, Yang Enterprises and Universidad Metropolitana. GBO is an institution of
National Science Foundation, operated under an Associated Collaboration Agreement
JPL hosts the Center for Near Earth
Object studies (CNEOS) for the Object Observation Program of NASA.
More information about CNEOS
For asteroids and near-Earth objects, see:
Learn more about
Planetary Defense Coordination Office of NASA, visit:
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The Arecibo Observatory can be found at:
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