SkyEye

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

The Sun and Moon

There is a partial eclipse of the Moon this month which is visible from the western United States, the Pacific Ocean, eastern Asia, and Australia. As seen from the Earth, the Sun is moving from the constellation Gemini to the constellation Cancer. The Earth is at aphelion on 6 July.

The phases of the Moon are

Last Quarter : 6 July
New : 13 July
First Quarter : 19 July
Full : 28 July

The Moon is at perigee on 11 July and at apogee on 23 July.

The Moon occults two planets and two first-magnitude stars in July. Like the previous three months, Neptune and Uranus are occulted a day apart. Neptune goes first on the first day of the month at 2 UT. This is visible during darkness in southern Europe and northern Africa. The occultation of Uranus the following day at 2 UT follows a similar pattern, being visible in the northern half of Africa. The arctic regions of Greenland and the British Isles have an opportunity to see Aldebaran slide behind the limb of the Moon during daylight hours on 10 July. Five days later, Greenland gets a repeat performance with Regulus, also during the day. Neptune again falls victim to the Moon on 28 July at 7 UT. This occultation is visible from the United States and Mexico and occurs during the partial lunar eclipse that night! The following night, at 6 UT, the southern United States, Mexico, and Central America can watch Uranus disappear behind the Moon's disk.

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 begins retrograde motion on 12 July and two weeks later reaches inferior conjunction. Thus, it is invisible during the last half of the month in the constellation of Cancer.
Venus
Venus is the "evening star" in the western sky after sunset. The Moon, Venus, and bright star Regulus appear close together in the sky on 15 July and Venus reaches its maximum brightness two days later. When viewed through a telescope, it appears crescent-shaped. Our sister planet begins retrograde motion on 27 July. Venus can be found in the constellations of Leo and Sextans.
Mars
Setting around midnight, the red planet can be found in the constellations of Virgo and Libra.
Jupiter
The largest of all planets in the solar system is at quadrature on 27 July, making this the best time to look for interesting shadow effects between the planet and its satellites. Jupiter rises about midnight in the faint constellation of Pisces.
Saturn
Saturn rises about the same time as Jupiter and can be found in the constellation of Aries. The rings of the planet are now at their most open in several years so get out those telescopes!
Uranus
Uranus is up all night with Neptune in the constellation Capricornus. Uranus is occulted by the Moon twice this month, on 2 July and again on 29 July.
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 is occulted twice by the Moon, on 1 July and again during the partial lunar eclipse on 28 July. The blue planet reaches opposition on 26 July and can be found in the constellation of Capricornus.
Pluto
Pluto sets early in the morning in the constellation Ophiuchus. However, because it is so small and faint, a large telescope is always needed to see it.

Minor Planets, Comets and Meteors

Minor Planets
The largest asteroid, 1 Ceres, undergoes conjunction with the Sun on 24 July.
Comets
There are no periodic naked-eye comets visible this month.
Meteors
Unfortunately, the delta Aquariids peak on 28 July which means they will be washed out by the strong light of the Full Moon. Perhaps some meteors will be visible during the partial lunar eclipse that evening.

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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