Despite having funds to spare, Musk isn’t a fan of lavish vacations – or any vacations for that matter. In 2015, he said he’d only taken two weeks off since founding SpaceX about 12 years earlier. He reportedly works 80 to 90 hours a week.

As a child growing up in South Africa, Musk taught himself to code. By the time he was 12, he sold the source code for his first video game for US$500.

Elon Musk may be the world’s richest rocket scientist. With a fortune hovering around US$20 billion, the 46-year-old CEO of Tesla and SpaceX and co-founder of OpenAI has said he won’t be happy until we’ve escaped Earth and colonised Mars. Luckily, he has the mind and the money to make it happen.

Next year's NASA budget is poised to force premature cancellation of either Curiosity or Cassini -- the agency's flagship missions. Funding decisions get made behind closed doors, but projected figures reduce Cassini's budget in 2014 by almost half, and half again in 2015, making it impossible to fly. Even funding for analyzing data will be "restructured," according to NASA. These cuts are not only devastating for scientists; they are also potentially harmful for our economy, and our leadership in STEM (Science, Technology, Engineering and Math).

The asteroid threat may be manna from heaven for the catastrophists, but it has to be taken into consideration: a serious and well-funded space programme must have the capacity to monitor large asteroids that could potentially destroy our planet. Small asteroids break up in the atmosphere at the rate of one every fortnight, but there are some that are over 100 metres in diameter that we should keep an eye on. Fortunately, we already have instruments that allow us (in most cases) to predict and study asteroids’ transit.

. The high costs are not associated (entirely) with the materials that leave Earth. Instead, they're associated with the technical challenges of building machines to rigorous specifications. To meet those technical challenges, we need lots of very smart engineers, and those engineers are developing all kinds of new technologies. Many of those new technologies can be turned to commercial uses, providing a direct economic benefit and making America one of the few nations in the world capable of revolutionary technological innovation.

Bush has proposed only $1 billion in new funding over the next five years, leaving the big bills for his successor–does it really makes sense to spend a significant sum to satisfy an idle curiosity when we can spend the money solving some other, equally daunting scientific challenge that would actually make people happier, healthier and better able to fulfill their capabilities in their brief time on earth?

Space exploration has also been one of the most powerful drivers of science and technology education in this country. Ask how many of today’s leading scientists and engineers were inspired by the space program and by the science-fiction shows and movies that fed off of it.

Yet there may be a sort of inadvertent benefit. Humanity may be more special than it seems. As Brownlee and Ward put it: "We are not the center of the universe, and we never will be.

Brownlee and Ward describe ten separate mass extinction events that have been recorded on Earth, and many more may have occurred.

Rare Earth Hypothesis": "the paradox that life may be nearly everywhere but complex life almost nowhere."

Does this suggest that Earth is unique? Stanley said that currently, this question is difficult to answer, because telescopes that search for exoplanets have a selection bias toward large, gas giant planets that orbit very close to their parent stars.

In 1961, astronomer Frank Drake wrote an equation to quantify the likelihood of finding a technologically advanced civilization elsewhere in the universe. The so-called Drake equation took into account factors such as the fraction of stars with planets around them and the fraction of those planets that would be hospitable to life.