Sky Calendar 2009 July

Visibility of planets

Mercury: It is very close to the Sun, difficult to observe it. On the beginning the month it emerges one hour before the Sun.

Venus: Strikingly bright in the east sky, high above the horizon. At the end of the month it rises three hours before the Sun. Its brightness is around -4,0 magnitude, the diameter decreases from 19" to 15", the phase increases from 0,61 to 0,73.

Mars: Forward motion in the Aries, Taurus constellations. Rises after midnight, can be seen at dawn in the southeast sky. Brightness is 1 magnitude, diameter increases from 4,9" to 5,3".

Jupiter: Backward motion in the Capricorn. Rises in the lately evening, can be seen in the biggest part of the night, in the south sky. Brightness is -2,7 magnitude, diameter 47".

Saturn: Forward motion in the Leo. Can be seen in the evening, it sets before midnight. Brightness is 1 magnitude, diameter 17".

Uranus: Rises before midnight, can be seen in the second part of the night. Backward motion in the Pisces.

Neptune: Rises in the evening hours, can be seen at the whole night.

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In honour of the Moon landing

A human first set foot on another world on July 20, 1969. This world was Earth's own Moon. In honor of the 40th anniverary, NASA has released a digitally restored video of this milestone in human history. Pictured below is Neil Armstrong preparing to take the historic first step.

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Comets

C/2006 W3 (Christensen): In this month the comet reaches its perihelium, wich comet was discovered by Eric Christensen on 18 November 2006, on the photos of the Catalina Sky Survey Schmidt-telescope. Its brightness has reached the 8 magnitude, what means, it can be observed with a binocular. Currently the comet is in the Pegasus, then Cygnus constellations.

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Meteor Showers

Since at the peak of the Perseids the Moon has an inauspicious phase, the main meteor shower in the summer is the Delta-Aquarids. The shower is active from July 14 to August 18, the maximum peak is on July 28. In good circumstances around 5-10 meteors per hour can be observed.

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M22 the nearest globular cluster

Messier 22 is one of the brightest and remarkable clusters in the sky, and in paticular of those observable from mid-northern latitudes. It was the first of these objects to be discovered. M22 is a very remarkable object, at 10 400 light years, its is one of the nearest globular clusters.

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