On 16th - 17th February Venus passes just 0.2º south of Jupiter but is difficult to observe in northern latitudes in the bright evening twilight. Observors in tropical latitudes, just north of the Equator, will have the best view. The next favourable conjunction of Venus and Jupiter will be on 15th March 2012.

On the 8th June 2004, Venus was at inferior conjunction and transited the sun. Transits of Venus are rare, taking place at greater than 100 year intervals and usually in pairs. The last two transits of Venus were in 1874 and 1882. June's transit began at 7.20h and lasted 6 hours until 13.20h, the total event visible from Europe as a small black disc crossing the lower part of the Sun from left to right. The next transit will be in late June 2012. After that, transits of Venus won't occur again until 2117 and 2125.

At opposition on the 28th August 2003, Mars was only 56 million kilometres from the Earth. It showed a disc of 25.1 seconds of arc across which is almost as large as it can ever appear. Mars started 2003 at 310 million kilometres from the earth at 4.5 seconds of arc and 1.6 magnitude. By opposition it brightened 50 times to reach -2.9 magnitude but faded to 0 magnitude by December. Even to the naked eye Mars was a striking object in the summer and autumn sky, easily identifiable by its reddish hue in an area of sky poor in bright stars. Mars will not be as close again until 2018.

These favourable oppositions occur every 15 or 17 years but other oppositions occur at average intervals of 2 years 2 months during which time the planet makes a complete circle of the Earth. In general Mars is observable every other year, being too close to the sun for favourable conditions during other times. Brightness at opposition varies from -1.0 to -2.9 magnitude, and when furthest from the earth it fades to 1.7 magnitude. The planet can be identified by its orange-red colour.

As in 2003, Mars comes nearest to the Earth at oppositions at the end of August. At these times it can be brighter than Jupiter, although low in the sky in Aquarius for northern observors. In the northern hemisphere, the planet may be better seen at oppositions during autumn and winter months when it is higher in the sky.

Observing Mars in 2010

Astronomy, Missions, Mythology & Astrology

During the conjunction with Venus, mentioned under Venus, Venus will be six times as bright as Jupiter.

Varying from 603 (at its closest) to 770 million kilometres from the sun, the difference in brightness between opposition and conjunction varies less than with Mars, from about -2.9 to -1.8 magnitude. Always a bright planet, Jupiter comes to opposition a month later each year, moving approximately from one zodiacal constellation to the next.

The 4 largest moons of Jupiter are easily visible through a small telescope, ranging from 4.6 to 5.6 in magnitude. The innermost, Io, takes 1.8 days to orbit the planet making its motion easily detectable within a few minutes.

Observing Jupiter in 2010

Astronomy, Missions, Mythology & Astrology

The diagram shows Saturn´s rings closing with the south pole presented towards Earth and the far side of the rings no longer appearing clear of the planet´s body. In 2009 the Earth passed through the ring plane making the rings invisible for a short while. It was the first time since 1997 that the planet´s magnitude has faded to this level.

Saturn moves more slowly than Jupiter and can remain in the same constellation for several years. The brightness of the planet depends on the aspect of its rings, as well as its distance from Earth and the Sun.

The planet crossed the equator into the northern hemisphere in 1996 where it will remain until 2010 with the southern side of the ring system facing the earth. Because of its distance, its brightness varies little between opposition and conjunction but is affected by the huge ring system. Seen edge on the rings contribute little or no light.

Every 15 years the plane of Saturn's rings passes through the sun, illuminating first the north and then the south side. For a few days the rings are edge on to the sun. About the same time the Earth passes through the ring plane and, depending on the Earth's position, this may happen just once or 3 times. During 1995/96 there was a triple crossing and the next will be 2038/39. The last single crossing was in 2009 and the next will be 2025.

Saturn's largest moon, Titan, is visible in small telescopes orbiting outside of the ring system.

Observing Saturn in 2010

Astronomy, Missions, Mythology & Astrology

Astronomy, Missions, Mythology & Astrology