Context. Video observations of Jupiter obtained by amateur astronomers over the past eight years have shown five flashes of light with durations of 1-2 s. The first three of these events occurred on 3 . Previous analyses of their light curves showed that they were caused by the impact of objects of 5-20 m in diameter, depending on their density, with a released energy comparable to superbolides on Earth of the class of the Chelyabinsk airburst. The most recent two flashes on Jupiter were detected on 17 March 2016 and 26 May 2017 and are analyzed here. Aims. We characterize the energy involved together with the masses and sizes of the objects that produced these flashes. The rate of similar impacts on Jupiter provides improved constraints on the total flux of impacts on the planet, which can be compared to the amount of exogenic species detected in the upper atmosphere of Jupiter. Methods. We extracted light curves of the flashes and calculated the masses and sizes of the impacting objects after calibrating each video observation. An examination of the number of amateur observations of Jupiter as a function of time over the past years allows us to interpret the statistics of these impact detections.Results. The cumulative flux of small objects (5-20 m or larger) that impact Jupiter is predicted to be low (10-65 impacts per year), and only a fraction of them are potentially observable from Earth (4-25 per year in a perfect survey). Conclusions. We predict that more impacts will be found in the next years, with Jupiter opposition displaced toward summer in the northern hemisphere where most amateur astronomers observe. Objects of this size contribute negligibly to the abundance of exogenous species and dust in the stratosphere of Jupiter when compared with the continuous flux from interplanetary dust particles punctuated by giant impacts. Flashes of a high enough brightness (comparable at their peak to a +3.3 magnitude star) could produce an observable debris field on the planet. We estimate that a continuous search for these impacts might find these events once every 0.4 to 2.6 years.

The VESPA data access system focuses on applying Virtual Observatory (VO) standards and tools to Planetary Science. Building on a previous EC-funded Europlanet program, it has reached maturity during the first year of a new Europlanet 2020 program (started in 2015 for 4 years). The infrastructure has been upgraded to handle many fields of Solar System studies, with a focus both on users and data providers. This paper describes the broad lines of the current VESPA infrastructure as seen by a potential user, and provides examples of real use cases in several thematic areas. These use cases are also intended to identify hints for future developments and adaptations of VO tools to Planetary Science.

Since 2003 the Planetary Virtual Observatory and Laboratory (PVOL) has been storing and serving publicly through its web site a large database of amateur observations of the Giant Planets (Hueso et al., 2010a). These images are used for scientific research of the atmospheric dynamics and cloud structure on these planets and constitute a powerful resource to address time variable phenomena in their atmospheres. Advances over the last decade in observation techniques, and a wider recognition by professional astronomers of the quality of amateur observations, have resulted in the need to upgrade this database. We here present major advances in the PVOL database, which has evolved into a full virtual planetary observatory encompassing also observations of

Amateur astronomers operating small telescopes accumulate a larger amount of observational time of Solar System planets than the ensemble of professional telescopes. Over the last 15 years, advancements in low-cost fast acquisition cameras and image software processing tools have pushed forward the scientific analysis of these observations thanks to a sustained increase in quality and spatial resolution. The high temporal coverage attained by amateur astronomers collaborating with scientists allows detecting rare events in the atmospheres of different planets. In particular, high-atmosphere phenomena in Mars, possibly caused by solar activity, and meteor impacts in Jupiter have been observed serendipitously in the last decade. Here we review the contribution of amateur astronomers to these two fields. Coronal Mass Ejections arriving to Mars under favorable observing conditions can be predicted after observations of the Sun, and their possible effect on Mars upper atmosphere can be monitored with small telescopes. Impacts in Jupiter of two different classes can be discovered by amateur astronomers: intermediate size impacts big enough to leave a debris field on its atmosphere (150-m size objects before the impact), and fireballs caused by objects of 5–20 m producing short-lived flashes in video observations of the planet. In this regard, we present a software tool designed to analyze video observations of Jupiter and Saturn that should help to find new impact flashes on the giant planets.