What was it like when Venus and Mars both died?

They all possessed volcanoes, watery oceans, and complex interactions between the surface, oceans, plus clouds and hazes, enabling these worlds to retain significant amounts of the heat they absorbed from the Sun. Moreover, at these very early stages, even the compositions of their atmosphere were similar, as they were all rich in molecules like hydrogen, ammonia, methane, nitrogen, and water vapor. For a time, conditions were favorable for life to potentially arise on all three worlds, and indeed it may have arisen on all three at some point in the distant past. However, on all but one of these worlds, it didn’t last. Venus experienced a runaway greenhouse effect, boiling its oceans away and rendering it inferno-like after only a few hundred million years. Mars lasted far longer before becoming inhospitable: perhaps as much as 1.5 billion years. These are the stories of our how planetary neighbors met their respective demises. <a href="https://medium.com/starts-with-a-bang/what-was-it-like-when-venus-and-mars-both-died-af572fee74c3">Website</a>