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The following is a discussion of just a few of the many objects that may be seen up in the sky, this week, July 6 to July 12, 2008.

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International Space Station

The ISS is visible every morning this week but most passes are low in the northern sky and are visible for only a minute or two. The brightest and highest passes are
Monday July 7 at 3:42 am. ISS appears in the west and disappears in the northeast.
Wednesday July 9 at 2:56 am. ISS appears in the north and disappears in the northeast.

Sun

There are no active regions visible on the sun's disk as of today, Sunday. For those of us near 40 degrees north latitude on
Sunday July 6 sunrise is 5:41 am and sunset is 8:34 pm
Saturday July 12 the sun rises at 5:45 am and sets at 8:32 pm MDT

Moon

The moon is at lunation 4 (that is 4 days after new) just before it sets on Sunday evening. It is at first quarter on Wed. July 9 at 10:35 pm MDT. By Saturday, July 12, the moon will be at lunation 10. This week is a great time to explore near the terminator, that is the line between the dark side and the illuminated side. Features near the terminator are illuminated by the rising sun and cast long shadows. This increases the contrast and makes subtle rilles, domes, and other geologic feature a bit easier to see.

Planets

Mars and Saturn appear quite close together this week. Look for them straight west about 15 degrees above the horizon an hour after sunset. On Thursday they are closest together at 40 arc minute apart. Mars is magnitude +1.7 and the semidiameter is 4.3 arc sec. Mars is 202 million miles from Earth. Saturn is magnitude +1.2 and the semidiameter is 16.6 arc sec. Saturn is 929 million miles from Earth.

Jupiter is at opposition, that is it is directly opposite the sun in the sky early Wednesday July 9th at 2 am. It is currently located in the constellation Sagittarius. Jupiter is magnitude -2.6 in brightness and the semidiameter is 47.4 arc sec; distance is 387 million miles. The great red spot crosses center of Jupiter's disk at the following times this week:
Wed. July 9 at 1:47 am
Wed. July 9 at 9:38 pm br/>Fri. July 11 at 3:25 am
Fri. July 11 at 11:16 pm
The great red spot is visible about an hour before and after the times noted. The planet Mercury may be seen before sunrise in the northeast in constellation Gemini. It is magnitude -0.5 in brightness. It is 96 million miles from Earth.

Comets

The following is a list of comets may be brighter than magnitude +12 this week.
C/2007 G1 (Linear) is in constellation Scorpius. It is magnitude +11.9 (position July 12 at 10 pm is RA 16 05 50 Dec -29 02 42)
C/2007 N3 (Lulin) is in constellation Capricornus. It is magnitude 10.5 (position July 13 2am is RA 20 28 02 Dec -17 28 36 )
C/2008 J1 (Boattini) is in constellation Cepheus. It is magnitude +10.2 (position July 13 2 am is RA 22 03 27 Dec +70 31 14)
C/2006 OF2 (Broughton) is in constellation Perseus. It is magnitude +11.4 (position July 13 2 am is RA 02 40 28 Dec +42 13 05)
C/2007 W1 (Boattini) is in constellation Cetus. It is magnitude +5.5 (position July 13 at 6 am is RA 03 13 15 Dec +07 29 35) Recent images show a 0.5 degree long tail.
15P/Finlay is in constellation Taurus. It is magnitude +10 (location July 13 5 am RA 04 28 12 Dec +22 50 37)

Summary

This week the ISS makes some brief low passes in the early morning. Mars and Saturn appear close together and may viewed in the same field through binoculars or low power telescope. Craters, domes, and other features may be viewed along the terminator on Earth's moon. Several comets may be located after the moon sets in the early morning. Join with the Longmont Astronomical Society or other club in your area as we view some of the great objects visible up in the sky this week.