So it was only pure luck that Lovells calculation on the motions of Uranus and Neptune had led to the discovery of Pluto! Astronomers are now asking what else could be pulling on Uranus and Neptune. The answer seems to be a massive planet lying much farther out in the solar system.
Bob Harrington, of the US Naval Observatory, has calculated that this planet is currently in the southern part of the sky. Every few weeks, telescope in New Zealand, at the Black Birch Astrometric Observatory near Blenheim, takes photographs of Harrington’s suspect part of the sky.
Harrington has allies in his research that no previous planet hunter could call on space probes. If planet 10 is pulling on Uranus and Neptune, it should also disturb the parts of the three spacecraft – Pioneer 10, Pioneer 11 and Voyager 1 – that are currently leaving the solar system. Scientists are measuring theirs motions carefully, to see if planet 10 is pulling them off-course. So far, the results are negative.
Other astronomers are not convinced by the calculation made so far. They believe that planet 10 could be anywhere in the sky, and so they are taking a different approach. Planets produce copious amount of infrared radiation. In 1983, the infrared astronomical satellite scanned the whole sky, looking for objects in the universe that produce infrared radiation. If planet 10 exists, then the satellite will probably have picked it up. The results from this survey were recorded on 60 miles (100 km) of computer tape. Astronomers, using this vast amount of data, have located many interesting objects comets, asteroids and newborn stars but planet 10 has still to come to light.
Picture Credit : Google