We begin a new decade swamped by visions of our planet in peril. Australia is in flames; Greenland and Antarctic ice shelves are crumbling; thousands of species face extinction, and millions of humans are at risk of losing their homes as sea levels rise and deserts spread.
At the same time, amounts of carbon dioxide in the atmosphere – the cause of the global heating that threatens to ravage our world – continue to increase unabated. Our future is being threatened in a manner that would have seemed unthinkable only a couple of decades ago.
It may therefore seem odd at this time for scientists to look away from our afflicted world and to take a renewed interest in issues that lie beyond Earth – in robot probes and vehicles that will take human beings beyond our atmosphere to the moon, Mars and the rest of the solar system.
Yet this renewed interest in extraterrestrial matters is real as we make clear in our survey of forthcoming space missions.
Not since the heyday of the space race to the moon in the 60s has so much space activity been planned, though this time missions will not be dominated by America and Russia but will also involve China, India and Japan as well as private companies such as SpaceX and Boeing, which plan to launch their own manned spaceships.
For good measure, the European Space Agency, of which Britain is a major, active participant, has also decided over the past few weeks to step up its commitment to space exploration with a €12.5bn (£10.7bn) package of projects.
Some of these missions will have a bearing on our planet’s present plight, of course. For example, Europe is planning a new fleet of satellites that will monitor carbon dioxide emissions at every point on Earth and so create the first global system for tracking key polluters. Many other observation satellites are planned and should help scientists contain the ecological threats of global heating.
However, there is another aspect of interplanetary travel that is relevant to the woes afflicting Earth. From space, we get a proper appreciation of our world and its vulnerability.
Until we sent probes to Mars and Venus, we thought our nearest planetary siblings could easily support life. Instead, spacecraft showed that Venus is an acid-drenched, scorching vision of hell while neighbouring Mars was found to have lost most its atmosphere aeons ago.
Exactly why these worlds went wrong, in terms of their abilities to support life, is not clear but the matter certainly merits further research.
The special perspective of our world that is provided by space missions was summed up by the late astronomer Carl Sagan when he described an image of Earth that had been beamed back by the Voyager 1 probe from a distance of 4bn miles in 1990. In that photograph, our world appeared as a tiny, single point of light.
“That’s here. That’s home. That’s us,” said Sagan of this pale blue dot. “Our posturing, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.”
And that, ultimately, is what space exploration really tells us. It says there is no Planet B and no chance of starting over again if we continue to make a mess of this world. The view from above shows Earth is precious and needs a lot more care and attention than it is getting at present.