LAST Spring, just as the buds on the trees at Jodrell Bank Observatory were beginning to open, a group of people in jeans and sweaters gathered around a computer screen. The windows of the office looked out at the 76m high white telescope out of which poured the secrets of the universe.
Unfortunately each secret came heavily coded, presented not as a clear image, but as a portrait of radio emissions, incomprehensible to the average person, but rather beautiful to those with brains the size of small planets. On that spring day a te
am from the school of physics and astronomy at St Andrews University were snooping around a distant part of the universe. The neighbourhood, in which they were nosying, was a long, long way away. Light travels at 186,000 miles per second and it would take 520 years to reach the constellation of Taurus.
The subject of their scientific scrutiny was a young star called HL Tau, thought to be less than 100,000 years old, a mere infant compared with our own wizened sun, which is 4,600 million years old. Yet it was while looking at the computer screen's digital images that the team found their eyes being drawn to a strange cluster of images in the right hand corner. The object, eventually represented as squiggles of red, green and gold, was curious – could it, thought Dr Jane Greaves, the team's leader, be a new planet?
It was exactly that. Dr Greaves and her colleagues across Britain and America were able to lay claim to the discovery, not only of a new planet, but the youngest ever discovered. The "protoplanet", as they are called, has been christened HL Tau B, after its parent, the star HL Tau. Yesterday, Dr Greaves said: "It was a eureka moment – I was gobsmacked, just amazed."
The outcome was a result of a rare opportunity to use a large array of telescopes across the US. The "very sharp" images taken of HL Tau and its surroundings revealed the presence of super-large rocky particles about the size of pebbles, a clue that rocky material is beginning to clump together to form planets. The big surprise was that, as well as detecting super-large dust in the disc around HL Tau, an extra bright "clump" was seen in the image. It confirmed tentative "nebulosity" reported a few years earlier, but shows the same system in much greater detail. The finding was confirmed by readings from telescopes based at the Jodrell Bank Observatory in Cheshire and supported by computer simulations from the University of Edinburgh.
She said: "We caught this planet at its very very earliest stages of forming – it is an embryo of a planet more than anything else. It is still contained within the disc of very young material out of which the star – which is also still in the process of forming – has been made. We took an image with a group of radio telescopes with much higher detail than anyone has ever managed before. The images provide a unique view of planet formation in action, and the first picture of a protoplanet still embedded in its birth material. It is the first time anyone has managed to look at a disc like this in such high resolution. The planet is not more than 100,000 years old – that's the equivalent of a day in a human life – but could be as little as 1,600 years old.
"There is another star in a similar region of space, and it is possible that they could have passed each other about 1,600 years ago, and that would basically give the disc of material a yank and make it unstable. If that is true, the planet would amazingly have started forming around then. We saw this really large ball of gas and dust – which is 14 times the size of Jupiter – which is in the earliest possible stage of a planet developing.
"With Jupiter having a mass 318 times that of Earth then the new planet is currently 4,452 times the size of our home. It will eventually crunch down over millions of years into something like a heavier version of Jupiter – so it will always be massive. It is just amazing that we can tell so much about this planet from all the way down here."
The death last month of Arthur C Clarke, the scientist and author who thought up the orbiting satellite, was disappointing as there is a feeling that man is, once again, on the cusp of a great age of space exploration and, given his achievements, he deserved to bear witness.
The advent of the space vacation is only a few years distant as Virgin Galactic begins scheduled flights into sub-orbital space next year. The European Space Agency is advertising for candidates for an astronaut programme for the first time in 20 years, and the Space Shuttle is soon to be replaced by a new model. There is talk of man returning to the Moon and firm advocates of a manned mission to Mars.
Meanwhile, orbiting telescopes and the increasing power of computers are opening the window wider into deep space and revealing ever greater wonders. Yet there are those critics who believe that the billions of pounds of research and development spent on space exploration would be better directed at tackling the problems of the world. It is a sentiment that , understandably, is not shared by Anita Heward of the Royal Astronomical Society, which was founded in 1820 to assist "gentleman astronomers" and now has 3,000 members drawn from astronomy, solar-system science, geophysics and other closely related branches of science.
Ms Heward said: "What is happening now is that the more you look, the more you find and the more answers you discover the more questions you come up with. Ten years or more ago we did not know about all these new planets we are now discovering outside our solar system. The possibility of finding an Earth-like planet is becoming ever closer. Our instruments are becoming increasingly sensitive and so the possibility of discovering life is coming closer. I would say that has to be the Holy Grail – finding life in the universe and we are slowly edging towards that. I think statistically it's highly likely that there is something out there."
Dr Greaves added that scientists hunting for Earth-like planets should be less "narrow minded" about the environments they look in, thanks to this discovery.
She explained: "We really were amazed to see this, as it wasn't actually what we set out to do. We had an inkling that by looking for dust grains – which are actually rocks the size of your fist – we could see if rocks were coming together around the star to form a planet.
"But this was much further out than where we expected to find anything – it is twice as far away from its star as Neptune is from the Sun. What it highlights is that other planetary systems must be amazingly diverse. It tells us that we shouldn't be too narrow minded when we are searching for a star that could have an Earth-like planet near it. The environments could be very very different, and we have to think about how this affects these solar systems."
Dr Greaves argues that the more we discover about the barren, lifeless aspects of the universe, the more we should cherish our own fortune to exist. The birth of the environmental movement followed on from the first photograph of the planet Earth, hanging suspended in the blackness of space. She said: "I think astronomy and space exploration helps us to see our place in the universe and remind us to look after the planet."
KEEPING TRACK OF THE CHANGING SKYTEN new planets have been discovered in the last six months by an international team of astronomers using two batteries of cameras, one in the Canary Islands and one in South Africa.
The ten new planets (commonly known as extrasolar planets) are in orbit around other stars. The results from the Wide Area Search for Planets (SuperWasp) was announced yesterday by Dr Don Pollacco of Queen's University Belfast, in his talk at the Royal Astronomical Society National Astronomy Meeting.
Scientists have found more than 270 extrasolar planets since the first one was discovered in the early 1990s. Most of these are detected through their gravitational influence on the star they orbit – as it moves the planet pulls on the star, tugging it back and forth. However, making these discoveries depends on looking at each star over a period of weeks or months and so the pace of discovery is fairly slow.
SuperWasp uses a different method. The two sets of cameras watch for events known as transits, where a planet passes directly in front of a star and blocks out some of the star's light, so from the Earth the star temporarily appears a little fainter. The SuperWasp cameras work as robots, surveying a large area of the sky at once and each night astronomers have data from millions of stars that they can check for transits and hence planets. The transit method also allows scientists to deduce the size and mass of each planet.
Each possible planet found using SuperWasp is then observed by astronomers working at the Nordic Optical Telescope on La Palma, the Swiss Euler Telescope in Chile and the Observatoire de Haute Provence in southern France, who use precision instruments to confirm or reject the discovery.
The SuperWasp planets have masses between a middleweight 0.5 and a huge 8.3 times that of Jupiter, the largest planet in our solar system.
A number of these new worlds are quite exotic. For example, a year on Wasp-12B (its orbital period) is just 1.1 days. The planet is so close to its star daytime temperature could 2,300C.
