Science Portal

Arecibo Observatory

Next Generation Arecibo Telescope

The white paper: “The Future of the Arecibo Observatory: The Next Generation Arecibo Telescope”, outlines how investing in a pioneering concept for a new telescope and cutting-edge instrumentation at the Arecibo Observatory will continue to propel discovery and humankind’s understanding in the fields of Planetary Science, Space and Atmospheric Sciences, and Astronomy. + Read More


.: This section describes the facilities that are currently operational at the Arecibo Observatory and available for interested investigators and students that would like to use them for their corresponding research work.

Photo of the ALF Lidar

Arecibo Lidar Facility (ALF)

The work at the Arecibo Lidar Facility is mainly focused on the so-called mesosphere and lower thermosphere (MLT) region at around 85 – 115 km of altitude. The work also includes the stratosphere down to 30 km and ion observations as high as 160 km altitude. The MLT region is experimentally challenging to access as it is too high for aircrafts or atmospheric balloons and too low for satellites because of the atmospheric friction.

Remote Optical Facility (ROF)

The Arecibo Observatory Remote Optical Facility (ROF) is located in Culebra, a small island in the east of Puerto Rico’s archipelago (approximately 150 km from Arecibo Observatory). Culebra is a federal nature reserve and was chosen due to its geographical and climatological characteristics, as well as the low light contamination, making it a strategic site for optical experiments. The container with the domes on top in the left bottom pane hosts the optical and radio instrumentation and a control room, while the other is lodging for scientists and technicians.

e-Callisto Logo with a picture of the sun and the Earth


The Arecibo Observatory received in 2019 a CALLISTO ('Compound Astronomical Low frequency Low cost Instrument for Spectroscopy and Transportable Observatory') solar radio spectrometer. The CALLISTO spectrometer has proven to be a valuable tool for monitoring solar activity and for space weather research for 24h per day through all the year. It provides dynamic spectra of type II, III and IV radio bursts in the frequency range of 45 - 900 MHz.

12m telescope with Room temperature receivers

The Arecibo Observatory (AO) operates a 12-m diameter parabolic reflector antenna. It is an alt-azimuth mount telescope with primary focal length to diameter ratio of 0.375. It is fully steerable covering an elevation range 10o - 88o. The telescope is equipped with room temperature, dual polarized receivers operating near 2.21–2.34 GHz (S-band) and 8.1–9.2 GHz (X band). The antenna was commissioned in 2011, but was not regularly used for astronomy observations. During 2021, the AO engineering team (Phil Perillat, Felix Fernandez, Luis Quintero and the technical staff) integrated the receiver system with Mock Spectrometer and VLBI backend and successfully commissioned the system for astronomy observations by December 2021.

Photo of the AOF

Arecibo Optical Lab (AOL)

The optical instruments at AO have been collecting high quality optical data since the 1960s. The mission of the Arecibo Optical Laboratory (AOL) and its Remote Optical Facility (ROF) is to continually improve the research-to-operations (and its reciprocal) data collection and dissemination necessary to address urgent national enterprises as Space Weather forecasting and Climate Change investigations.


.: This section describes the programs, facilities and instruments that are currently under development at the Arecibo Observatory.

Big Data Program

The Arecibo Observatory has gathered an enormous amount of data since it began operations in 1963. At that time, it was never imagined the storage and computing resources that the data would require to be effectively processed. Technology has improved vastly since we opened over 57 years ago. Big Data, a field in computing, has taken a lot of relevance as organizations require to efficiently store, manage and process large datasets. Here at AO, we are not the exception. The Big Data Program at AO was created to implement the benefits of this field into the scientific nature of our organization.

Culebra Aerosol Research Lidar

CARLA’s research instrument, a high spectral resolution aerosol lidar, will be developed at the main site of the Arecibo Observatory (AO) and, thereafter, installed at the Remote Optica Facility of the AO in Culebra island. CARLA will deliver information about aerosol properties over time and altitude.

Wideband (2.3 – 14 GHz), Cryogenic Front-end for the 12m telescope

The poor system performance and relatively narrow bandwidth of the room temperature receivers of the 12m telescope are not widely useful for radio astronomy observations. Therefore we are upgrading the current receiver system with a wideband (2.3 – 14 GHz), cryogenic frontend. The expected system temperature is about 35 K over the full bandwidth. This upgrade will enable novel radio astronomy projects that range from tracking inhomogeneities in the solar wind, illuminating the underlying physics of pulsars and searching for FRB and sensitive spectral line observations of the galactic plane (see the list below). The cryogenic system is fully funded by the National Science Foundation. The system will be built by CryoElec LLC, Arizona and the work will start in April 2022.

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Radio Astronomy is the study of radio waves produced by a multitude of fascinating astronomical objects such as the Sun, planets, stars, pulsars, star-forming regions (i.e., birthplace of stars), gas clouds, galaxies, supernova remnants, and more. The radio signals from these objects give astronomers a plethora of physical information across vast distances and scales in our Universe, from a three-dimensional view of the energetic solar wind from our Sun, to the composition of exoplanetary atmospheres around other stars, to the motion of distant galaxies. To detect even the weakest radio signals requires a dish with a large surface area, and the enormity of the 305-meter Arecibo radio telescope allows astronomers to detect these faint radio waves from far-off regions of the Universe. The Radio Astronomy Group at Arecibo consists of scientists who are not only users of the telescope but who also use their expertise to help other astronomers to plan and carry out their observations. Explore below some current highlights of the exciting research done by both staff and astronomers all over the world at one of the largest single-dish radio telescopes on Earth, the Arecibo Observatory.

Space & Atmospheric Sciences

Atmospheric Science is the investigation of the earth's gaseous envelope. Experiments performed at Arecibo measure upper atmosphere composition, temperature and densities in order to understand the controlling physical processes. The Arecibo Radio Telescope can measure the growth and decay of disturbances in the changing layers of charged particles which populate the region known as the ionosphere ( altitudes above 30 miles ). The "big dish" is also used to study plasma physics processes in the electrically charged regions of the earth's atmosphere. where radio waves are influenced most.

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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 305-meter 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 the Earth. This radio echo is processed then analyzed to yield information about the size, shape, spin, density, composition, surface properties, geology (e.g., ridges, craters, and boulders) of the object, and also allows to identify binary and triple asteroid systems. The Arecibo Planetary Radar System can measure the distance to an asteroid, typically millions of km away, with a precision of meters, and 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 to support planetary defense.”

CAVEAT: The Arecibo Observatory is sponsored by the National Science Foundation. Any opinions, findings and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.