Search

Since the formation of the Solar System some 4.55 billion years ago, the Sun has provided the necessary conditions to allow life on Earth to begin forming, evolve and thrive. As a main sequence star, the Sun is exhausting its reserves of hydrogen at its core over time as it is fused into helium. Once this process – known as solar reddening – has been completed and helium fusion begins in the core, the Sun will become a red giant. This evolution will lead to fluctuations in the solar properties such as mass, luminosity, radius and surface temperature. While solar-reddening will likely be catastrophic for the inner-most planets, it could present an opportunity for Saturn’s moon Titan and the dwarf planet Pluto as the Sun’s luminosity increases. Titan and Pluto are of significant interest due to their photochemically-active atmospheres, both of which are mostly made up of nitrogen with traces of methane. We will present a model for simulating planetary atmospheres in orbit around reddening stars, with case-studies investigating how Titan and Pluto’s atmospheric and surface conditions will change between the solar ages of 4.55 and 12.15 Gyr. Our model builds upon the TitanIC (Titan Irradiative Chemistry) model, first created by Borg (2015). We will also present how the model can also be used to simulate exoplanet atmospheres of known initial compositions for a host star with a given set of solar parameters.Borg, J., 2015. Projecting the Evolution of Titan’s Atmosphere under a Reddening Sun. University of Malta., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

This paper illustrates the Italian BIstatic RAdar for LEo Survey (BIRALES) sensor for Space Surveillance and Tracking in the LEO regime. BIRALES is a bistatic radar whose receiving part has been refurbished to synthetize up to 32 simultaneous beams in the antenna field of view. The multibeam configuration offers the possibility of estimating the track of the detected objects inside the receiver field of view by analysing the beams illumination sequence. The estimated track is then coupled with the available Doppler shift and slant range measurements. The availability of such a plethora of information is then exploited to perform initial orbit determination with a single passage of a resident space object inside the sensor field of view. This work describes BIRALES sensor setup and operation, showing the performance of the sensor in terms of observation and tracking capabilities.

If you were to travel back in time to Earth’s distant past, about three billion years ago, you would find a planet bearing barely any semblance to today’s world. A toxic atmosphere primarily composed of methane swathed our planet as its surface, devoid of liquid water at the time, was incessantly bombarded by small asteroids. While time travel evades our current realm of possibilities, we do have a replica of this past, primordial Earth right in our cosmic backyard!, N/A

The aim of this article is to present the architecture proposed for the bistatic radar BIRALES (BIstatic Radar for LEo Surveys) as an instrument for space debris detection in the framework of the European Space Surveillance and Tracking Support Framework (EUSST). In the following paragraphs, the architecture and the upgrades done so far will be presented, as well as the multibeam technology and system calibration. Eventually, the orbit determination algorithm both for known and unknown objects is described, along with the numerical simulation.