18
April
2017
|
15:32 PM
America/New_York

Arecibo refines our understanding of a potentially hazardous asteroid

Radar reveals the asteroid to be twice as big as previously thought

UPDATE 1: April 19 - Estimates of the size and rotation period have been adjusted since an earlier draft of this press release.

UPDATE 2: April 20 - Observations on April 19 show the largest dimension of the body is at least 870 meters, significantly longer than the visible extent seen on April 17.

Columbia, MD and Puerto Rico—April 18, 2017. The Arecibo Observatory in Puerto Rico this week observed potentially hazardous near-Earth asteroid 2014 JO25 as part of its planetary radar program sponsored by NASA’s Near-Earth Object Observations (NEOO) program. Arecibo radar observations revealed that the asteroid is twice as big as was previously thought and has a lumpy, peanut shape.

2014 JO25 was discovered in May 2014 by the Catalina Sky Survey and designated a potentially hazardous asteroid based on its size and relative proximity to Earth. Prior to accurate radar measurements, its diameter was estimated using data from the NEOWISE spacecraft to be 650 meters (2130 feet), more than twice the size of the Arecibo telescope's reflector. The Arecibo Observatory Planetary Radar system, which is the most sensitive and the most active in the world, has now provided direct measurement of this asteroid’s size, shape, rotation, and near-surface geology.

“Using radar, we can illuminate a near-Earth asteroid and directly measure its features. In this case, we found 2014 JO25 to be a contact-binary or peanut-shaped asteroid,” noted Dr. Edgard Rivera-Valentín, Planetary Scientist with the Universities Space Research Association (USRA) at Arecibo Observatory. “Each lobe is between about 640 m - 670 m (2100 ft - 2198 ft) in diameter for a total size of about 1.3 kilometers (4270 feet; 0.8 miles) along its widest point, so twice as large as inferred using infrared data from the NEOWISE spacecraft" continued Rivera-Valentín. Additionally, Arecibo data suggests 2014 JO25 rotates about once every 3.5 hours.

Not all asteroids are spherical. In fact, Dr. Patrick Taylor, Group Lead for Planetary Radar at Arecibo notes “About 1 in 6 near-Earth asteroids are contact binaries, which could have formed as two asteroids failed at orbiting each other and fell back together. There are as many of these contact binaries as there are true binaries, asteroids with their own moons.”

“Because radar can very precisely measure an asteroid’s distance from Earth and how fast it is moving, we can better predict where this object will be in the future,” said Luisa Fernanda Zambrano-Marin, graduate student and researcher with USRA at Arecibo. “The data we provide to NASA’s NEOO program helps us evaluate an asteroid’s impact hazard to Earth and helps NASA evaluate appropriate deflection strategies if needed,” continued Zambrano-Marin.

Though designated as potentially hazardous, asteroid 2014 JO25 is not a threat to Earth at this time and will safely pass by Earth on April 19 at 4.6 times the distance between the Earth and Moon. Current models predict it will not make a similar close approach to Earth for another 900 years. The next known close approach by an object of similar size is in August 2027 by 1999 AN10, which is estimated to be 800 meters (2620 feet) in diameter. Further observations of 2014 JO25 will be conducted by NASA’s Goldstone Solar System Radar located in the Mojave Desert of California.

About AreciboThe Arecibo Observatory is a facility of the National Science Foundation (NSF) operated under cooperative agreement by SRI International in alliance with Universities Space Research Association (USRA) and Universidad Metropolitana. The Arecibo Observatory Planetary Radar Program is fully supported by the National Aeronautics and Space Administration (NASA) by grants from the Near-Earth Object Observations program to USRA.

About USRAUniversities Space Research Association is an independent, nonprofit research corporation where the combined efforts of in-house talent and university-based expertise merge to advance space science and technology. USRA works across disciplines including biomedicine, planetary science, astrophysics, and engineering and integrates those competencies into applications ranging from fundamental research to facility management and operations. USRA engages the creativity and authoritative expertise of the research community to develop and deliver sophisticated, forward-looking solutions to Federal agencies and other government sponsors.

(left) Delay-Doppler image captured by the Arecibo Observatory Planetary Radar System. In this image, the peanut-shaped nature of this asteroid is readily visible as well as potential geologic features, such as a peak on the front half of the asteroid and a rounded double-lobed nature to the back half of 2014 JO25. (right) Movie of the rotation of 2014 JO25 produced by combining several delay-Doppler images. The movie spans 2 hours of observations. (both) Vertical resolution is 7.5 m/pxl.

 

 

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About Arecibo

The Arecibo Observatory is a facility of the National Science Foundation (NSF) operated under cooperative agreement by SRI International in alliance with Universities Space Research Association (USRA) and Universidad Metropolitana. The Arecibo Observatory Planetary Radar Program is fully supported by the National Aeronautics and Space Administration (NASA) by grants from the Near-Earth Object Observations program to USRA.

About USRA

Universities Space Research Association is an independent, nonprofit research corporation where the combined efforts of in-house talent and university-based expertise merge to advance space science and technology. USRA works across disciplines including biomedicine, planetary science, astrophysics, and engineering and integrates those competencies into applications ranging from fundamental research to facility management and operations. USRA engages the creativity and authoritative expertise of the research community to develop and deliver sophisticated, forward-looking solutions to Federal agencies and other government sponsors.

Contact: Dr. Edgard G. Rivera-Valentin, Technical ContactSuraiya Farukhi, USRA PR ContactRicardo Correa, Arecibo PR Contact