In those days when it was thought that the earth is at the centre of the Universe, the sky was imagined as a big sphere. All the stars were fixed on this sphere from inside. Thus the configuration of the stars never changed. This sphere was called `celestial sphere'. The celestial sphere rotated round the earth once every twenty hours. All the stars remained fixed at their respective places. There were however a few naughty stars that wandered around. Wandering star literally mean planet. Two other objects, the sun and the moon too were free to move on the celestial sphere. The path of the sun on the celestial sphere is called ecliptic.

Eventually, it was discovered that the wandering stars, the planets, do not wander aimlessly but are they move in well-defined orbits. It was also discovered that the planets move almost in the same plane. The path of the planets (and also that of the moon) on the celestial sphere is therefore very close to the ecliptic.

Mother Nature offers her live demonstration of the planets on ecliptic this month. Watch the sunset and as it gets dark you will find Venus, Jupiter and Saturn almost on the same line right above where the Sun has set. The line is also most vertical.

As the months starts the moon will be very bright. We had the Blue Moon on January 31. On the 16th the moon will rise along with the sun. Annular eclipse of the sun takes place. On this day the moon is a bit too far from the earth and thus appears a little smaller. On the other hand the earth is a bit closer to the sun and the sun will appear slightly bigger. As a result, even though the moon wil be directly between the earth and the sun it will not be able to hide the sun completely behind it and a ring of fire will be seen. We will not see this event from Pune.

From the next day a very high level drama begins. On 17th you can spot Mercury just below the thin crescent of the moon. On this day you will see the old moon in the new moon's arms. Just after the sunset keep looking in the direction where the sun had set and soon you should be able to locate the thin crescent of the moon. Just below this thin crescent the bright object will be Mercury.

On the 18th the moon will be fairly above the horizon but it still will be a crescent. It will be between Jupiter and Venus. On next day, the moon will be almost halfway between Saturn and Jupiter. And on the 24th the moon can be seen right next to Saturn.

As the moon climbs above the horizon we also see Venus rapidly climbing above the western horizon though not as fast. But Jupiter is now taking a plunge into the western horizon. Thus the distance between the moon and Jupiter is rapidly decreasing.

It would appear that both the planets are on collision course with each other. If you have a 4 or 6 inch telescope you will be able to see both the planets in the same field of your eyepiece on the 23rd. Surely those not keeping track of what is happening in the sky but happen to see the western sky will report something unusual in the sky. By the month-end Jupiter will be almost 5 degrees below Venus but about 6 degrees above Mercury.

We have been saying time and again that you must try a bit of celestial photography. Now, do not miss this opportunity. On a 400 ASA film an exposure of one twentyfifth of a second will let you capture the planets. Of course you must also give two more exposures of one fiftieth and one twenty-fifth of a second.

Mars rises by about 11 p.m. by mid-month. The earth will be half way between Mars and the Sun on 18th. Even though this is not the closest approach of the earth to Mars it is the closest the earth will get to Mars for next year. It will not be difficult to see the polar caps of Mars this month.

This month even Neptune and Pluto make their presence felt to non-observing people. Pluto regains its old title of being the farthest planet. About 20 years ago the orbit of Pluto had brought it inside the orbit of Neptune. For the last two decades Neptune was the farthest planet in the solar system. On 11th of February by about 3.40 p.m. Pluto will again be the farthest planet and will remain so for next 230 years.

Some astronomers however are not quite happy about the status of planet given to Pluto. They think Pluto is an oversized asteroid. Well, presently a heated debate is on about the planetary status of Pluto. We will soon know if we will have nine planets in the solar system or we will go back 69 years in time when we knew of only 8 planets.

Pluto was discovered by Clyde W. Tombaugh on the night of February 25, 1930 on photographic plates he exposed to the sky on January 23rd and 29th. Tombaugh died on January 17, 1997 two weeks and four days before his 91st birthday.