\begin{table}%t1
%\centering
\par
\caption{\label{table1}Comparison between the orbital (at J2000.0) and physical parameters of Venus necessary for our study and the corresponding ones for the Earth.}
\small \begin{tabular}{lccc}
\hline \hline
& Earth & Venus  \\
\hline
Semi-major axis & 1.000001~U.A &0.723332 U.A &\\
Eccentricity & 0.0167 & 0.0068 &  \\
Inclination  & 0 & 3.39 & \\
Ascending node &174.87 & 7667 &  \\
Period of revolution  & 365.25 d & 224.70 d &   \\
Density & 5.51 $\mathtt{g/cm^3}$ & 5.25 $\mathtt{g/cm^3}$ &  \\
Equatorial radius & 6378~km & 6051~km &  \\
Mass &$ 5.97 \times 10^{24}$ kg&$ 4.87 \times 10^{24}$ kg &  \\
Obliquity  & 23.43 & 2.63 &  \\
Period of rotation  &0.997 d & --243.02~d &\\
Triaxiality: $\frac{A-B}{4C}$ & $ -5.34 \times 10^{-6}$ & $ -1.66 \times 10^{-6}$ \\ 
Dyn. flattening: $\frac{2C-A-B}{2C}$ &  $ 3.27\times 10^{-3}$ & $ 1.31 \times 10^{-5}$\\
$\frac{B-A}{2(2C-A-B)}$ & 0.0016 & 0.12  \\
\hline
\end{tabular}
\vspace*{2.5mm}
\end{table}