How do clouds of neutral hydrogen atoms transform into molecular clouds, the birthplaces of all stars in our galaxy? This is an unanswered question in galactic astronomy that some scientists are investigating using the Arecibo Observatory (AO).

A unique, high-altitude plasma cavity formed over Arecibo during an ionospheric heating campaign conducted at the observatory in June of 2019. Simultaneously, the Arecibo Incoherent Scatter Radar (ISR) collected measurements of the narrow cavity, revealing an exceptionally deep depletion of the electron density and a strong enhancement of the electron and ion temperatures. Read More

In the 2030’s, two spacecrafts - NASA’s Europa Clipper and the European Space Agency’s Jupiter Icy Moons Explorer (JUICE) missions - will enter orbit around Jupiter to study the planet’s largest moons. Until then, observations of the Galilean satellites - named for their discoverer - are restricted to observations from Earth. Read More

New results from the AO Remote Optical Facility (ROF) have shown that certain wavelike perturbations in the Earth’s ionosphere are highly dependent on season in a variety of ways. For the first time, these perturbations – known as Medium Scale Traveling Ionospheric Disturbances (MSTIDs) - were conclusively shown to be modulated by the geomagnetic and solar activities.