SkyEye

Welcome to SkyEye, your guide to this month's celestial events. All dates are based on Universal Time (UT).

The Sun and Moon

The last total solar eclipse of the millennium occurs on 11 August and is visible from Europe. As seen from the Earth, the Sun is moving from the constellation Cancer to the constellation Leo.

The phases of the Moon are

Last Quarter : 4 August
New : 11 August
First Quarter : 19 August
Full : 26 August

The Moon is at perigee on 7 August and at apogee on 19 August.

The Moon occults three planets and two first-magnitude stars in August. Aldebaran glides behind the limb of the Moon on 6 August at 16 UT. This is an night-time event in Japan and a daytime one in Alaska and Canada where this occultation can be seen. Four days later, Mercury disappears behind the Moon for any lucky observers near the North Pole. The North Pole gets to see another occultation, this one of Regulus on 12 August. Like the previous four months, Neptune and Uranus are occulted a day apart. Neptune goes first on the 24 August at 14 UT. This is visible during darkness in India and southeast Asia. The occultation of Uranus the following day at 13 UT follows a similar pattern, being visible in the southeast Asia during the hours of darkness.

The Planets

The word planet is derived from the Greek word for "wanderer." Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars.
Mercury
Mercury resumes prograde motion on 5 August and and is occulted by the Moon five days later. This closest of all planets to the Sun reaches greatest elongation west on 14 August and is best seen in the northern hemisphere shortly before sunrise. Mercury can be found in the constellations of Cancer and Leo.
Venus
The "evening star" for the past few months, Venus disappears early in the month for northern observers as it approaches inferior conjunction on 20 August. The best views of this planet are in the southern hemisphere. Telescopes show it as a large, thin crescent. Venus can be found in the constellations of Sextans, Hydra, and Cancer.
Mars
The red planet reaches east quadrature on 7 August and should appear slightly gibbous in a telescope. It sets before midnight in the constellation Libra.
Jupiter
The largest of all planets in the solar system begins retrograde motion on 25 August. Jupiter rises in the small constellation of Aries just as Mars sets in the west.
Saturn
Saturn rises at about the same time as Jupiter and also can be found in the constellation of Aries. It reaches west quadrature on 9 August, making this an excellent time to look through a telescope for interesting shadow effects between the planet, its satellites, and its rings. It joins Jupiter in retrograde motion on the last day of the month.
Uranus
Uranus is up almost all night with Neptune in the constellation Capricornus. Uranus is at opposition on 7 August and is occulted by the Moon on 25 August.
Neptune
Neptune is falling behind Uranus after their triple conjunction in 1993, but they are still found close together in the sky. Like Uranus, Neptune also is occulted by the Moon, this time on 24 August. The blue planet is up nearly all night and can be found in the constellation of Capricornus.
Pluto
Pluto sets around midnight in the constellation Ophiuchus. However, because it is so small and faint, a large telescope is always needed to see it. It resumes prograde motion on 21 August.

Minor Planets, Comets and Meteors

Minor Planets
A number of interesting minor planets populate the solar system.
Comets
There are no periodic naked-eye comets visible this month, but comet 10P/Tempel 2 makes its 25th visit to the inner solar system since its discovery in 1873 by Wilhelm Tempel. The comet reaches perihelion early next month and may become as bright as tenth magnitude, meaning that you will need a telescope to see it as it moves from Ophiuchus to Sagittarius to Microscopium.
Meteors
Fortunately, the famous Perseids peak on 12 August, just after New Moon, which means that the sky will be dark all night long. Perhaps some meteors will be visible during the total solar eclipse the previous day!

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union (IAU) recognizes 88 different constellations. The brightest stars as seen from the Earth are easy to spot but do you know their proper names? With a set of binoculars you can look for fainter objects such as nebulae and galaxies or some of the closest stars to the Sun.

Descriptions of the sky for observers in both the northern and southern hemispheres are available for the following times this month. Subtract one hour from your local time if daylight savings time is in effect. (Note: These times are approximate.)

Northern Hemisphere : 45° N

Southern Hemisphere : 30° S

For More Information...

Blue moons, eclipses, the dates of Easter and much more can be found at the Interactive Astronomy Pages. For more information about the objects and events described in SkyEye, visit these astronomy-related sites.

Credits

Much of this information can be found in this month's issue of Sky & Telescope and in other fine amateur astronomy magazines available in your local bookshop. Another excellent source is the current edition of the Astronomical Calendar by Guy Ottewell and published by the Universal Workshop at Furman University.

The image of the Sun in the SkyEye banner is courtesy of the SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA.

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