Not long ago, my colleagues and I found some micrometeorites in the Pilbara region in Western Australia. What’s truly remarkable about them is that these tiny meteorites can tell us a great deal about the chemistry of Earth’s atmosphere 2.7 billion years ago.

It’s easy to assume that astronauts float in space because they are far away from the Earth’s gravitational force. But look at the moon. It is much further away than the International Space Station, yet it orbits around the Earth because it is perpetually attracted by its gravitational pull. So if the Earth’s gravity can affect the moon, the astronauts cannot be floating because there is no gravity where they are.

One solitary asteroid might be worth trillions of dollars in platinum and other metals. Exploiting these resources could lead to a global boom in wealth, which could raise living standards worldwide and potentially benefit all of humanity.

What would it take to hide an entire planet? It sounds more like a question posed in an episode of “Star Trek” than in academic discourse, but sometimes the bleeding edge of science blurs with themes found in science fiction.

Alpha Centauri is our nearest stellar neighbor and might be the target of a new research program planning to send a tiny spacecraft to the nearest stars. But is it the right place to look for extraterestial life?

We live on a moving target in a cosmic firing range. Each day, the Earth is bombarded by about a hundred tonnes of space debris. It may sound alarming, but this is really nothing to worry about. Most of the objects that fall towards our planet are pretty small – typically about the size of a grain of sand or even smaller – and burn up in the upper atmosphere tens of kilometres above the ground.

If the human race is to survive in the long-run, we will probably have to colonise other planets. Whether we make the Earth uninhabitable ourselves or it simply reaches the natural end of its ability to support life, one day we will have to look for a new home.

With interest in the prospect of mining the moon and asteroids gaining pace, it’s time to take a hard look at what’s really at stake.

Black holes have long been a source of much excitement and intrigue. And interest regarding black holes will surely grow now that gravitational waves have been discovered. Many of the questions I am asked regard how “true” science fiction concerning black holes might be, and whether worm holes, such as those featured in Stargate, are real or not. Invariably though, the one item that is almost assured to come up are the largely gruesome ways in which black holes might theoretically affect human beings and the Earth itself.

Crashing into a planet is seldom a good idea. If you’re trying to travel to another world, you’re likely to land at tens of kilometres per second unless you do something serious to slow down. When Neil Armstrong famously became the first man on the moon in 1969, he piloted a lunar module onto the surface using thrusters that slowed the craft’s descent.

With a growing number of Earth-like exoplanets discovered in recent years, it is becoming increasingly frustrating that we can’t visit them. After all, our knowledge of the planets in our own solar system would be pretty limited if it weren’t for the space probes we’d sent to explore them.

Tim Peake is the first official British astronaut to walk in space. The former Army Air Corps officer has spent a month in space, after blasting off on a Russian Soyuz rocket to the International Space Station on December 15 last year, but the spacewalk will doubtless be his most gruelling test.

The nature of dark energy is one of the most important unsolved problems in all of science. But what, exactly, is dark energy, and why do we even believe that it exists?