Planetary Sciences

The Arecibo Planetary Radar is used to study celestial bodies in our solar system such as planets, moons, asteroids and comets. Directed by the 1000-foot reflector, a powerful beam of radio energy is transmitted in the direction of the target object. A small portion of this energy is reflected by the target, back in the direction of earth. This radio echo is processed then analyzed to yield information about the size, shape, spin, density, composition, surface properties, and geology (e.g., ridges, craters, and boulders) of the target object. The Arecibo Planetary Radar System can measure the distance to an asteroid, typically millions of km away, with a precision of meters; it can measure the speed of an asteroid, typically tens of kilometers per second, with a precision of millimeters per second. Arecibo’s precision can greatly refine asteroid orbits, aiding NASA in its congressionally mandated mission to study near-Earth objects and helping assess the impact hazard of potentially hazardous objects.

Science Group

The Planetary Radar Science group is a department of the Arecibo Observatory, which is an NSF facility operated under cooperative agreement by SRI International, USRA, and la Universidad Metropolitana (UMET). The Arecibo Observatory Planetary Radar program is fully funded through grants to USRA from NASA's Near-Earth Object Observations program (Grants NNX12AF24G and NNX13AQ46G). The Planetary Radar Science group is also partnered with the Center for Lunar Science and Exploration node (USRA-Lunar and Planetary Institute/NASA-Johnson Space Center) of the NASA Solar System Exploration Research Virtual Institute program.

Recent News

Arecibo Planetary Radar Returns to Action with Images of Asteroid Phaethon

Phaethon - Figure 1
Planetary December 22, 2017

Columbia, MD and Puerto Rico: After several months of downtime in the aftermath of Hurricane Maria, the Arecibo Observatory Planetary Radar returned to normal operation providing the best images to date of near-Earth asteroid 3200 Phaethon, which is thought to be the parent body for the Geminids meteor shower. Radar images reveal Phaethon to be roughly spherical with a diameter of about 6 km (3.6 mi), roughly 1 km (0.6 mi) larger than previous estimates. Read More

First Asteroid Detection since Hurricane Maria   December 12, 2017

Radar Observations and Shape Model of Asteroid 16 Psyche   Jul 21, 2017

Arecibo refines our knowledge of a potentially hazardous asteroid  Apr 17, 2017

Arecibo Observatory captures revealing images of Comet 45P/Honda-Mrkos-Pajdusakova   Feb 12, 2017

Discovery Announcement of Binary System (163693) Atira   Jan 20-23, 2017

Asteroids by the AO Planetary Radar Group

Planetary Radar Group


Dr. Anne Virkki

Postdoc Research Scientist
Dr. Flaviane Venditti

Dr. Flaviane Venditti

Postdoc Research Scientist
Dr. Sean  Marshall

Dr. Sean Marshall

Postdoc Research Scientist

Luisa Fernanda Zambrano-Marín

Research Asst.

Graduate Students
  1. Jenna Crowell, University of Central Florida, Advisor: Yan Fernandez
  2. Agata Rozek, University of Kent, Advisor: Stephen Lowry
  3. Adam Greenberg, University of California, Los Angeles, Advisor: Jean-Luc Margot
  4. (Undergraduate) Benjamin Sharkey, University of Minnesota, Twin Cities, Advisor: Charles Woodward

  1. Michael C. Nolan, Staff Scientist, Head of Planetary Radar, and Site Director
  2. Ellen S. Howell, Staff Scientist
  3. Alessondra Springmann, Data Analyst
  4. John K. Harmon, Staff Scientist
  5. Alice A. Hine, Staff Scientist
  6. Jean-Luc Margot, Postdoc
  7. Donald B. Campbell, Staff Scientist and Site Director
  8. Carolina Rodriguez Sanchez-Vahamonde, Research Assistant / Observing Support