The discovery of thousands of exoplanets orbiting distant stars in our Galaxy has only heightened our interest in further understanding the origins, evolution and fate of our own solar system - what we can learn from our neighbourhood will inform our future observations of these distant worlds, which will become a working reality with the launch of the JWST (James Webb Space Telescope), the successor to the HST (Hubble Space Telescope). Observations of our solar system involve the use of ground and space based observatories, as well as the analysis of robotic spacecraft 'in situ', and despite centuries of observations of even the largest of the planets, Jupiter, we are still making new discoveries about these fascinating objects. 


Movie 1: Whole sky seen over 24 hours sampled at 9 second integrations, radio 'light' on the left (taken with Caltech's Owens Valley Long Wavelength Array), optical on the right (obtained simultaneously using the all-sky camera at Caltech's Palomar Observatory). The correlation in emission from the Milky Way is apparent - the dazzling bursts later correspond to solar flares. Credit: Stephen Bourke/ Caltech and the LWA team.


Dr. Aaron Golden

Joining the Group

 If you are interested in pursuing a PhD in this area of astronomy, please contact to see how best to make this happen.

Research Outline

The recently formed Planetary Astronomy group is currently engaged in two specific observational programmes, one involving planetary atmospheres, and the second focusing on the study of comets.

Electrostatic Discharges in Planetary Atmospheres

Electrostatic discharges - lightning - provide a unique and powerful means to time, track and electrostatically characterize intense meteorological events within a planetary atmosphere, probe its associated ionosphere, as well providing constraints on the production of non-equilibrium organic molecules, many of which are of significant astrobiological relevance. These discharges manifest themselves, as they do terrestrially, by means of their optical flash and associated high and low frequency radio emission – optical flashes have been detected on Saturn and Jupiter, and HF radio bursts from 100s of kHz to ~ 40 MHz have been detected from all the outer planets bar Jupiter, where it is believed the intense ionospheric environment absorbs such HF emission.

Using the Long Wavelength Array radio telescope (LG002 *"LWA Monitoring of Electrostatic Discharges from Saturn and Uranus"*), located in the New Mexican desert next to the Jansky Very Large Array, we are actively monitoring the planets Saturn and Venus, in conjunction with NASA/ESA's Cassini and JAXA's Akatsuki, with the goal of detecting coincident low frequency electrostatic discharges from both planets. Previously we observed the planet Uranus during its extraordinary storm activity in the late summer/early autumn of 2014.

Figure 1: The Long Wavelength  Array (LWA1) located next to the National Radio Astronomy Observatory's Very Large Array in New Mexico, USA - this telescope operates between 10-88 MHz using a phase-array of 256 dipole antennas. Credit: The LWA consortium.

Temporal Studies of Cometary Nuclei

Using NASA's K2/Kepler observatory, we have been allocated time during Campaign 12 and 13 to observe several Jupiter Family comets, 1 Main Belt Comet and the Centaur Chiron as they serendipitously pass across K2's field of view during its ~ 80 day observation of the same star fields (GO13033 *"Serendipitous Observations of Short Period Comets by K2"*). Our principal goal is the acquisition of sufficiently deep Long Cadence photometry to derive the rotational period for all the cometary nuclei, and to track the evolution of the cometary comae and associated dust production for those that are active. Taken together these datasets will increase by almost 50% the known rotation rates for this solar system population, providing additional constraints to models of nuclear composition/density, size, spin rate evolution and providing important baseline data to identify excited modes of rotation.

Figure 2: Comet Siding Spring observed in October 2016 as it passed across the field of view of NASA's Kepler spacecraft. Each 'box' corresponds to one of the 22 CCD panels at the focal plane of Kepler's telescope. In the blow up image, the comet's motion during the 30 minute exposure is clearly evident by the oblong shape of the cometary nucleus. Credit: NASA Ames/W Stenzel; SETI Institute/D Caldwell

In addition, long baseline monitoring of dust production at ∼ 30 minute resolution from several active comets at differing heliocentric distances/ranges will give a unique temporal insight into dust production from these objects. These observations have been supported by Target-of-Opportunity time on NASA's Swift Observatory, and ground-based observations from the Vatican Advanced Technology Telescope in Arizona using the GUFI high speed photometer.


Dr. G. Fischer (Space Research Institute (SRI), Austrian Academy of Sciences, Graz, Austria)


In preparation.