Accretion of planets may be occurring around these stars, just as it did in the early solar system. They must explain or account for similarities and differences in the characteristics of the planets. The sun's equator lies roughly in the ecliptic Planetary orbits are nearly coplanar. All planetary orbits are prograde.
Planetary orbits are nearly circular.
Many Satellite orbits are prograde. Most planets rotate prograde. Overall abundance ratios of chemical elements in the Jovian planets are like those in stars. Jovian planets are further from the sun than terrestrial planets. Oldest planetary surfaces are heavily cratered.