Search Publications
Advanced method to derive the IMF direction near Mars from cycloidal proton distributions
Kallio, E.; Fedorov, A.; Barabash, S. +7 more
In a previous paper, we showed a method for deriving the interplanetary magnetic field (IMF) orientation from the velocity distribution of ring-like distributed ions as measured by the Ion Mass Analyser (IMA) on board Mars Express (MEX). This method has been improved so that one can derive the IMF orientation from a very limited portion of the rin…
Huygens probe entry dynamic model and accelerometer data analysis
Colombatti, Giacomo; Aboudan, Alessio; Ferri, Francesca +1 more
During the first phase of Huygens arrival into Titan's atmosphere the probe is subjected to gravitational and aerodynamic forces in aerodynamic hypersonic regime. Atmospheric drag exerts a strong deceleration on the capsule measured by Huygens atmospheric structure instrument (HASI) servo accelerometer. A 6 DOF (Degree of Freedom) model of the Huy…
The Venus ground-based image Active Archive: A database of amateur observations of Venus in ultraviolet and infrared light
Barentsen, Geert; Koschny, Detlef
The Venus ground-based image Active Archive is an online database designed to collect ground-based images of Venus in such a way that they are optimally useful for science. The Archive was built to support ESA's Venus Amateur Observing Project, which utilizes the capabilities of advanced amateur astronomers to collect filtered images of Venus in u…
Saturnian icy satellites: Disk-integrated observations of the brightness opposition surge at low phase angles
Kulyk, Irina
Photopolarimetric observations of Saturn's satellites Enceladus, Tethys, Dione, and Rhea were obtained with the 2 m RCC telescope at the National Astronomical Observatory, Rozhen, in two different phase-angle regions (from 0.07° to 0.01° and from 5.6° to 5.2°). In this paper we present the first results of disk-integrated satellite photometry incl…
Upstream proton cyclotron waves at Venus
Russell, C. T.; Wei, H. Y.; Zhang, T. L. +2 more
Data from the magnetometer MAG aboard the Venus Express S/C are investigated for the occurrence of cyclotron wave phenomena upstream of the Venus bow shock. For an unmagnetized planet such as Venus and Mars the neutral exosphere extends into the on-flowing solar wind and pick-up processes can play an important role in the removal of particles from…
The Huygens scientific data archive: Technical overview
Colombatti, Giacomo; Aboudan, Alessio; Lebreton, Jean-Pierre +31 more
The Cassini/Huygens mission was launched in October 1997, and during the third orbit around Saturn, the Huygens probe was released on course to enter Titan's atmosphere. During the descent, six science instruments provided in situ and remote sensing measurements of Titan's atmosphere and surface. Doppler tracking was performed with two Earth-based…
Variations of the magnetic field near Mars caused by magnetic crustal anomalies
Kallio, E.; Fedorov, A.; Janhunen, P. +2 more
The possible avenues for photoelectron transport were determined during southern hemisphere winter at Mars by using a mapping analysis of the theoretical magnetic field. Magnetic field line tracing was performed by superposing two magnetic field models: (1) magnetic field derived from a three-dimensional (3D) self-consistent quasi-neutral hybrid m…
A conceptual model for explanation of Albedo changes in Martian craters
Yue, Z.; Zhu, M.; Xie, H. +3 more
We propose a conceptual model to interpret AM/PM high albedo events (HAEs) in crater interiors at the Martian seasonal polar caps. This model consists of two components: (1) a relatively permanent high-albedo water-ice body exposed in a crater interior and (2) a variable crater albedo in response to aerosol optical depth, dust contamination, and H…
Predicted interplanetary shocks/particles at Mars compared with in-situ observations: An overview
McKenna-Lawlor, Susan M. P.
The biological and technological consequences of long-duration, solar-related, energetic particle radiation for manned/unmanned spacecraft warrant that consideration be given to providing reliable space weather predictions for future space missions to planet Mars. An account is, herein, provided of how the HAFv.2 numerical model was applied to pre…
Ground-based astrometric observations of latitude for improved reference frame
Damljanović, Goran
The Commission 19 (Earth Rotation) of the International Astronomical Union - IAU established the Working Group on Earth Rotation in the Hipparcos Reference Frame - WG ERHRF at 1995 to collect the optical observations of latitude and universal time variations, made during 1899.7-1992.0 in line with Earth orientation programmes (to derive Earth Orie…