One of my favourite magazines is called Astronomy. In its latest issue it lists the 25 greatest astronomical discoveries of all time and it makes fascinating reading.

Clearly there are the achievements of the great scientists of the past:

• The reticent Polish cleric Nicolas Copernicus and his view that the Earth went around the Sun and not vice versa (1543)
  
• The eager Galileo who in 1609 turned a crude telescope towards the sky and saw craters on the Moon, the satellites of Jupiter and the phases of Venus
  
• And of course the eccentric Sir Isaac Newton and his theory of gravity (1687)
  
• Then we have the discovery of the planets Uranus and Neptune in the 19th century; the measurement of star distances (1838) the speed of light (1675) and the classification of stars (1890).
  
• Things really start moving in the past century; the mapping of our galaxy and the recognition that it is only one of myriads in space (1923); the development of radio astronomy to provide a new look at the universe (1932)
  
• There is also the more recent discoveries of the distant and energetic quasars (1963) and the small, superdense spinning stars called pulsars (1967)

But what is listed as astronomy's greatest hits for the past 25 years?

• There is the discovery of planets around nearby stars (1995)
  
• The confirmation of supermassive black holes at the heart of distant galaxies (early 1990's)
  
• Err
  
• That is it

Now, consider this. There are more astronomers working today than ever before. In fact some say that there are more astronomers now than in the whole of history combined.

Their equipment has never been so expensive. Telescopes cost hundreds of millions of pounds and some space observatories have cost many billions.

Of course scientific problems get harder because if they were easier they would have been solved by now. There is no rule that says asking deep questions of nature should be a pushover. Also, in general, astronomers are among the cleverest people on the planet. But...

What is there to show for it? A few pretty pictures from the Hubble Space Telescope; an image of rocks on Mars?

Ask any astronomer and they will readily tell you what the great mysteries of space and time are;

What is 99 per cent of the universe made of?

Will the universe expand forever of stop and implode?

Is there life out there?

But most astronomers are not working on these problems. Instead they are finding out things about planets, stars and galaxies that add footnotes to scientific progress at best. Writing papers that in the cosmic scheme of things are not that important.

Of course I am being facetious but there is a point here.

About 25 years ago astronomers asked for money to build the Hubble Space Telescope to solve the mystery of the fate of the universe.

But one American politician said that just a few years earlier they had given them lots of money to build an array of radio telescopes to do just the same thing. How many times, he asked, can they ask for more money to do the same thing?

Discuss.