When the first baby is born off-Earth, it will be a milestone as momentous as humanity's first steps out of Africa. Such a birth would mark the beginning of a multi–planet civilization for the human species.

For the first half-century of the Space Age, only governments launched satellites and people into Earth orbit. No longer. Hundreds of private space companies are building a new industry that already has US$300 billion in annual revenue.

I'm a professor of astronomy who has written a book and a number of articles about humans' future in space. Today, all activity in space is tethered to the Earth. But I predict that in around 30 years people will start living in space—and soon after, the first off-Earth baby will be born.

The players in space

Space started as a duopoly as the United States and the Soviet Union vied for supremacy in a geopolitical contest with loud military overtones.

A NASA team has found that organic salts are likely present on Mars. Like shards of ancient pottery, these salts are the chemical remnants of organic compounds, such as those previously detected by NASA's Curiosity rover. Organic compounds and salts on Mars could have formed by geologic processes or be remnants of ancient microbial life.

Besides adding more evidence to the idea that there once was organic matter on Mars, directly detecting organic salts would also support modern-day Martian habitability, given that on Earth, some organisms can use organic salts, such as oxalates and acetates, for energy.