It's been a humbling few weeks for many of us. Devastating scenes in Japan from the earthquake, tsunami and now the nuclear crisis serve as a reminder how lucky many of us are.

For me, this was followed by watching Comic Relief charity event in the UK on March 18 and seeing the poverty in Uganda on the TV — it was nothing short of shocking. In the same period, I was closely following NASA's MESSENGER space probe as it dropped into orbit around Mercury, the nearest planet to the sun.

SLIDE SHOW: MESSENGER: First Photos from Mercury Orbit

I found myself wondering if it's right that we are spending all this money on space exploration when people on our own planet are suffering so horribly, either at the hands of Mother Nature or poor governments.

Mission to Mercury
Mercury itself has actually had quite a lot of press of late, as the last few weeks have been a great opportunity to try and observe this tiny elusive planet. When inner planets (Mercury and Venus) orbit around the sun and reach the extremes of their orbit as viewed from Earth, they are at their easiest to spot.

For Mercury, it's been on the eastern side of the sun so is said to be at "greatest eastern elongation," a mouthful that means it's worth trying to spot it low in the western sky after sunset.

It's been great to see the nearest planet to the sun, up close, and amazing to know that we've sent a tiny space probe there to study it. But for me, even more spectacular was watching Discovery dock with the International Space Station a few weeks ago.

That question about funding still nags at me though.

Big Numbers
The MESSENGER mission cost $280 million (which, in reality, isn't a vast amount for a space mission). The launch of a space shuttle costs $450 million and there have been about 130 of them. It cost $1.7 billion to build just one of the five-strong fleet.

Finally, the International Space Station has, over the years of its existence, cost an estimated $142 billion and that's not including the plethora of smaller space missions, other space agencies and other expenses involved in space exploration.

As you can see, these are big numbers. Yet there's an urgent need for funding to save lives down here on Earth, too.

Although space exploration certainly isn't over-funded, should we keep throwing money into space exploration when there are so many examples of human suffering?

More Money, Less Suffering?
A great effort this year saw the Comic Relief campaign raise £70 million ($114 million). But this is just one example; there have been countless great fund-raising efforts internationally over the years. Public fund-raising brings in money for these great causes, yet governments give billions in foreign aid too. The UK for example, gives around $11 billion each year in foreign aid.