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OPEN POSITION for Research Intern in the Planetary Radar Group

Job Summary/Basic Function: The University of Central Florida (UCF) and the Department of Planetary Radar Group at the Arecibo Observatory (AO) invites applications for the Research Intern position. The intern will participate in the research activities of the planetary radar group of the Arecibo Observatory. The details of the research projects will be tailored based on the level of background knowledge and skills of the successful applicant. This is a paid (stipend) internship position for undergraduate students only (starting year 2 or more). + Read More

OPEN POSITIONS for Postdoctoral Scientists in Planetary Radar

Two post-doctoral scientist positions are available in the planetary radar group at the Arecibo Observatory, Puerto Rico. The research emphasis of the group is the study and characterization of near-Earth objects and other solar system bodies. The incumbents will be expected to participate in radar data processing, analysis, and modeling of near-Earth asteroids and other solar system bodies observed using the Arecibo planetary radar system. We encourage applications from candidates with experience in any type of small bodies observations or research. Experience with radar observations and techniques, programming languages, and Linux systems is preferred but not required. Conference travel and equipment support are available. + Read More

The Arecibo Observatory has the world's most powerful planetary radar system, which provides ground-based observations whose quality could only be exceeded with a spacecraft flyby. The 305 meter Arecibo telescope equipped with a 1 MW transmitter at S-band (12.6 cm, 2380 MHz) is used for studies of small bodies in the solar system, terrestrial planets, and planetary satellites including the Moon.

Radar Astrometry

Since NASA’s near-Earth object observations program started funding the planetary radar program in November 2011, the annual number of radar-observed asteroids increased from less than 20 per year to more than 100. Roughly one half of the targets observed each year are recently discovered near-Earth asteroids (NEAs), which usually have large orbit uncertainties. Radar astrometry is a valuable tool for orbit refinement, providing precise measurements that can significantly improve the accuracy of orbit determination, preventing the object from becoming lost and requiring re-discovery in the future. In addition, Doppler and range measurements can increase the orbit predictability window from years to centuries, and quickly eliminate impact false alarms with the improvement of estimates of an asteroid’s orbital elements.

Physical Characterization

The Arecibo planetary radar is a powerful tool for post-discovery characterization of near-Earth objects, planets, and moons. In addition to precise line-of-sight velocity and range information, depending on the target’s size and distance, planetary radar is useful for quickly estimating the instantaneous rotation rate of near-Earth asteroids, resolving the target’s size, detecting potential satellites, and ultimately resolving the shape through inverse modeling efforts. Although comets rarely come close enough to Earth to allow strong enough echo, when an approaching comet becomes detectable by the planetary radar systems, it is possible to get clues to the size and spin period of the nucleus. Furthermore, radar signal can penetrate through clouds (such as the thick atmospheres on Venus or Titan), or several wavelengths below the regolith surface, providing insight to geologic features hidden from optical wavelengths, and provide clues to the near-surface bulk density or metal richness of the target based on its reflectivity at radar wavelengths. Radar polarimetry can give clues to the decimeter-scale surface structure, which is crucial for landing spacecrafts. The physical properties obtained with radar are fundamental information to support space mission’s planning, hence the majority of small bodies missions select targets that can be characterized with radar prior to the mission.

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The Arecibo Observatory Planetary Radar program is fully funded by NASA's Near Earth Object Observations Program and proudly supports NASA's efforts to track and characterize near-Earth objects for planetary defense. For information about asteroid and comet orbits, including close approaches to Earth, please see the websites of the NASA Center for Near-Earth Object Studies and the NASA Planetary Defense Coordination Office.

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A team of scientists, including AO data analyst Luisa Fernanda Zambrano-Marin and several previous AO scientists, derived the shape, features, and a global map of the asteroid. + Read More

Image Credit: NASA / ISS


Excited stargazers with a pair of binoculars were not the only ones to spot the bright comet C/2020 F3 NEOWISE last year!
A team of scientists at the Arecibo Observatory, led by postdoctoral researcher Dr. Allison Smith, aimed the massive 305-meter radio telescope at the celestial object with the goal of understanding how much water the comet was shedding as it approached the Sun.
The unique dataset collected at the Arecibo Observatory would be among the final observations made by the iconic radio telescope before it began experiencing cable failures that led to the telescopes collapse on December 1, 2020.
Comet NEOWISE, named for the near-Earth object (NEO)-hunting NASA Wide-field Infrared Survey Explorer (WISE) space telescope that was used to discover it, originated in the distant parts of our Solar System. Because of its distance from the Sun, it has likely remained relatively unaltered since it formed. + Read More


While the recent successful landing of the Perseverance rover furthers robotic exploration of Mars, some scientists are preparing for the next kind of mission to the Red Planet: human exploration. A recent study published in the scientific journal Astrobiology chronicles laboratory analyses of geologic samples collected during the AMADEE-18 mission, a humanrobotic Mars expedition simulation in the Dhofar region in the Sultanate of Oman. + Read More

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NOTE: Any opinions, findings, or recommendations expressed here do not necessarily reflect the views of the Arecibo Observatory, the National Science Foundation (NSF), University of Central Florida (UCF), Yang Enterprises (YEI), and Universidad Metropolitana (UMET), or the National Aeronautics and Space Administration (NASA). This website section is maintained by Dr. Sean Marshall