Mercury is often a difficult planet to find, but there are certain short periods each year when it can be seen with the naked eye with little effort, either just after sunset or before sunrise.
In 2009, Northern Hemisphere observers will find two periods when Mercury can easily be located. During the last half of April, Mercury can be seen low in the west-northwest soon after sunset. In early October, Mercury is well placed in the east-southeast before sunrise.
Southern Hemisphere observers will find Mercury well placed in the morning sky during February and will rise well before twilight begins. In late August, Mercury is well placed during the evening after sunset for southern observers.
|Date||Event||Degrees from Sun||Magnitude||N. Hemisphere||S. Hemisphere||Visibility|
|January 4||Greatest Elongation East||19||-0.5||Fair||Fair||Evening|
|January 20||Inferior Conjunction|
|February 13||Greatest Elongation West||26||+0.0||Poor||Good||Morning|
|March 20||Superior Conjunction|
|April 26||Greatest Elongation East||20||+0.3||Good||Poor||Evening|
|May 18||Inferior Conjunction|
|June 13||Greatest Elongation West||23||+0.6||Poor||Fair||Morning|
|July 13||Superior Conjunction|
|August 24||Greatest Elongation East||27||+0.3||Poor||Good||Evening|
|September 30||Inferior Conjunction|
|October 05||Greatest Elongation West||18||-0.5||Good||Poor||Morning|
|November 5||Superior Conjunction|
|December 18||Greatest Elongation East||20||-0.5||Fair||Fair||Evening|
Venus is well placed for observation most of the year. As 2009 begins, Venus is a brilliant "evening star" visible for a couple of hours after sunset. Inferior conjunction, when it is on the near side of the Sun relative to the Earth, is on March 27. Venus then becomes a "morning star" for the rest of the year. The planet can be seen in the daytime sky with the naked eye if one knows where to look for it, especially around the times of greatest brilliancy and greatest elongation. Try following the planet before sunrise when it is in the morning sky and keep an eye on it until after sunrise.
|January 14||Greatest Elongation East||-4.4|
|March 27||Inferior Conjunction||-4.0|
|June 5||Greatest Elongation West||-4.3|
Mars is not well placed for observation for most of 2009. It is a few weeks past conjunction with the Sun as the year begins, becoming visible in the morning sky in February. It reaches 10 arc seconds in diameter at the beginning of December, heading towards opposition on January 29, 2010. Even at opposition, it will be only 14.1 arc seconds in diameter, as compared with its size of 25.1 arc seconds in August 2003.
Except for a few days at the beginning of the year, Jupiter spends the whole of 2009 in Capricornus, making it slightly better placed for northern observers than it was in 2008. It will be high in the sky for southern hemisphere observers. It is best viewed in the morning sky from March until the August 14 opposition, when it moves into the evening sky. The angular diameter at opposition will be 48.9 arcseconds. Binoculars will show the four largest satellites. A small telescope will show two of the cloud bands across the visible surface of the planet.
Saturn will spend most of the year in Leo, moving into Virgo on September 2. Saturn can be viewed in the evening sky until August, when it approaches conjunction with the Sun. From October to the end of the year, it will be visible in the morning sky. The rings will appear edge-on in 2009, making them difficult to see in small telescopes. Saturn?s moons will be easier to see than usual because of the lack of glare from the rings. The ?missing? rings will also make Saturn much dimmer than usual to the unaided eye. The maximum possible tilt is 27 degrees, which last occurred in 2003. At opposition, the angular diameter will be 19.8 arc seconds.
Uranus is best viewed in late summer and early fall. It is in opposition on September 17, when it moves from the morning sky into the evening sky. Although it may be seen with the naked eye in a very dark sky, usually binoculars will be required to make it out. Its angular diameter is less than 4 arcseconds.
Neptune is best viewed during the late summer and early fall. It is in opposition on August 17, when it moves from the morning sky into the evening sky. Binoculars or a small telescope will be required to see it. The angular diameter is about 2 arcseconds.
Source: RASC - Observer's Handbook 2009