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Only seven transits of Venus have been observed and studied up to now since the first astronomical observations with the telescope: 1639, 1761-69, 1874-82 and 2004-12. The measurement of the Astronomical Unit has been one of the main goal…
The data of 2012 transit of Venus are compared with the ones of 2004. The thickness of the atmosphere of Venus, its aureole and the effect of oblateness and other asphericities in the figure of the Sun are taken into consideration, as well…
The transit of Mercury occurred two times in this century: 2003, May 7 and 2006, November 8. In 2016 there is another opportunity to observe this phenomenon and measure the solar diameter with the method of comparing the ephemerides with…
The role of Venus and Mercury transits is crucial to know the past history of the solar diameter. Through the W parameter, the logarithmic derivative of the radius with respect to the luminosity, the past values of the solar luminosity can…
The role of Venus and Mercury transits is crucial to know the past history of the solar diameter. Through the W parameter, the logarithmic derivative of the radius with respect to the luminosity, the past values of the solar luminosity can…
The possibility to measure the solar diameter using the transits of Mercury has been exploited to investigate the past three centuries of its evolution and to calibrate these measurements made with satellites. This measurement basically…
Many observers in the past gave detailed descriptions of the telescopic aspect of Venus during its extremely rare transits across the Solar disk. In particular, at the ingress and egress, the portion of the planet's disk outside the Solar…
Ground based observers have on 5/6th June 2012 the last opportunity of the century to watch the passage of Venus across the solar disk from Earth. Venus transits have traditionally provided unique insight into the Venus atmosphere through…
The main observations of 1761 by M. Lomonossov and those that followed are recalled by extending the discussion to other remarkable visual observations of the passages, then with more and more powerful imagers producing images in profusion.…
This work analyzes the X-ray, EUV and UV emission apparently coming from the Earth-facing (dark) side of Venus as observed with Hinode/XRT and SDO/AIA during a transit across the solar disk occurred in 2012. We have measured significant…
The variation of the solar diameter in time and in position angle has implications in astrophysics and in general relativity, as the long series of studies attest. The Transits of Venus in 2004 and 2012 have been carefully studied because…
The mesosphere of Venus is a critical range of altitudes in which complex temperature variability has been extensively studied by the space mission Venus Express (Vex) during its eight-years mission (2006-2014). Data collected at different…
Nowadays the more powerful method to detect extrasolar planets is the transit method. We review the planet transits which were anticipated, searched, and the first ones which were observed all through history. Indeed transits of planets in…
Large sunspots can be observed with the unaided eye under suitable atmospheric seeing conditions. Such observations are of particular value because the frequency of their appearance provides an approximate indication of the prevailing level…
The similarity of Mercury to the Moon raises the question on mercurian analogues of lunar transient phenomena. However, since the mid-1960s, this topic has remained out of attention. Nevertheless, the discoveries of the 21st century and the…
On 5-6 June 2012, Venus will be transiting the Sun for the last time before 2117. This event is an unique opportunity to assess the feasibility of the atmospheric characterisation of Earth-size exoplanets near the habitable zone with the…
To study the variations in the solar wind velocity during inferior conjunctions of Mercury and Earth, we analyzed 54 events in the period 1995 to 2012 by the superimposed epoch method. We have found a noticeable increase in the velocity…
We used the 8 June 2004 transit of Venus (ToV) as a surrogate to test observing methods, strategies and techniques that are being contemplated for future space missions to detect and characterize extrasolar terrestrial planets (ETPs) as…
The atmosphere of a transiting planet shields the stellar radiation providing us with a powerful method to estimate its size and density. In particular, because of their high ionization energy, atoms with high atomic number (Z) absorb…
I present the first systematic catalogue of simultaneous solar transits of both Phobos and Deimos as observed from the surface of Mars. Using the JPL mar099 ephemeris (Brozovic et al. 2025) and SPICE toolkit, I searched the millennium…