Find the great Red Spot

Dim figures crept around with shrouded torchlights as they attempted to locate favourable viewing positions and I could understand the enthusiasm associated with Star Parties in the United States to which amateur astronomers cheerfully drive hundreds of miles, their telescopes accommodated in trucks or trailers.

I did not see as many telescopes as I expected on this occasion but we certainly had the enthusiasm and the wide screen presentations on the night sky were superb and followed by identification of constellations. Blissfully lying back on my folding mattress with its comfortable grass underlay, I saw the Milky Way undimmed by urban light pollution and, looking north, south, east and west, located familiar but often obscured constellations with the greatest of ease.

At about 10 pm I saw an extremely bright light behind some trees to the east and wondered if it was an approaching plane. As it rose higher, however, I realised that I was looking at the second brightest planet visible this month — the great gas giant, Jupiter. I wasn’t the only impressed observer as beside me excited viewers were clustered around a telescope and I deeply regretted the unexpected contingencies which had prevented members of the Trinidad and Tobago Astronomical Society from bringing along at least one society telescope.

For those with telescopes, this is a good time to look for Jupiter’s famous Red Spot which will cross Jupiter’s meridian ( the imaginary line down the centre of the planet from pole to pole) at a number of reasonable viewing times during late May and June. These include 9.25 pm on May 20, 11.03 pm on May 22, 8.33pm on May 26, 9.18 pm on June 1, 9.57 pm on June 3 and 8.26 pm on June 6.

Jupiter rotates on its axis in the relatively short period of about ten hours so even a short spell at the telescope, under favourable observing conditions, will reveal many features in its upper atmosphere (the surface of the planet cannot be seen) including the movement of the Red Spot across the face of the planet.

The Red Spot is not as red as it was when it was first discovered in 1831 and its colour is now described as “pale orange-tan” (Sky and Telescope. May, 2006). It is found in Jupiter’s southern hemisphere and regions around it include a number of coloured belts crossing the planet and white and brown ovals. A newcomer to these Jovian ovals is a new, smaller Red Spot , called “Red Junior”, discovered in February 2006, which lies just below the Red Spot.

Similar bands and ovals are also found in the northern hemisphere and you may be fortunate enough to see one or two of Jupiter’s giant moons, preceded by their shadows, transit across the planet’s face. The four giant Jovian satellites, Io, Ganymede, Europa and Callisto are clearly visible like tiny pearls in the plane of the planet’s equator and their changing positions with time, as they pass in front of or behind the planet, are highly interesting to watch.

So! — take out that telescope you got as a Christmas present or have owned as a prized possession for some time and observe this king of planets.

Your excited exclamation as you find the Red Spot or some other interesting feature may bring out family members or your next door neighbour to share your pleasure. Point out that you are looking at a planet containing more material than all the other planets put together (its mass is 300 times the mass of the earth) which travels in its orbit at a speed of 47,160 km/hour (No speed traps in the solar system!) and with which a comet collided in 1994. We observed the “bruises’ caused by that collision from the rooftop of the Sir Frank Stockdale building at UWI and thought for a moment about what such a collision would do to the earth.

For more information on Jupiter and Trinidad and Tobago Astronomical Society viewing sessions phone 645-7238 or e-mail maura@trinidad.net.