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The following is a discussion of just a few of the many fascinating astronomical objects to view this week, Sept. 28 to Oct. 4, 2008.

Sun

On Sunday Sept 28 sunrise is at 6:56 am and sunset is at 6:50 pm mdt

On Saturday Oct 4 sunrise is at 7:02 am and sunset is at 6:40 pm mdt

There are no active regions visible on the solar disk (as of Sat. Sept. 27).

For more information about the sun and space weather, see www.swpc.noaa.gov

Moon

At moonrise on Sunday morning at 6:12 am the moon is at lunation 28.9.

The circumstances for spotting the waning crescent within 20 hours of new are good.

It is new at 2:12 am mdt on Monday morning.

The moon will be at lunation 4.7 Saturday evening.

Planets

Mars is visible very low in the west-southwest about 40 minutes after sunset. It is magnitude 1.6 in brightness and the disk is 3.8 arc sec across. It will be difficult to find in the bright twilight.

Venus is magnitude -3.8 and is easy to spot naked eye low in the west-southwest after sunset. The disk is 12.2 arc sec across. Venus sets around 8 pm.

Jupiter is straight south between 7:30 to 7:08 pm this week. It is magnitude -2.1 in brightness and 39.3 arc sec across.

Jupiter sets around midnight. The great red spot crosses the center of the disk at the following times this week:

Sun. Sept. 28 at 11:40 pm

Mon. Sept. 29 at 7:32 pm

Wed. Oct. 1 at 9:11 pm

Fr. Oct 3 at 10:49 pm

Neptune is in constellation Capricornus it is magnitude +7.9 in brightness, disk is 2.3 arc sec across.

Uranus is in constellation Aquarius. It is magnitude +5.7 in brightness and the disk is 3.7 arc sec across as seen from telescopes on earth.

Saturn rises around 5 am in constellation Leo. It is currently magnitude 1.1 in brightness and the planet's disk is 16.3 arc sec across.

Dark Sky Objects

Messier 2 in the constellation Aquarius is always worth a look. To locate it find the great square of Pegasus high up in the southeast. Note the distance between Alpheratz in the north east corner and Markab in the southwest. Start at the southwest corner star Merkhab and then look to west and a bit south the the same distance and you will see the 2.4 magnitude star Enif. Below it and a bit to the east is 3rd magnitude Sadalmelik or Alpha Aquarius. Further below and to the west is star just slightly brighter Beta Aquarius or Sadalsuud. About 3/4 of the way along a line between Enif and Beta Aquarius is M2.

It is an impressive object in scopes of all sizes. It is a large bright globular cluster with an intense central core (Type II) about 20 arc sec in diameter. In a large scope, look for dark lanes, the most prominent one is in the northeast. Globular clusters such Messier 2 are a spherical collection of stars orbiting a common core and are tightly bound gravitationally. Messier 2 is one of the largest globular clusters known at 175 light years across. It is about 37,500 light years from us here on earth. It is thought to contain 150,000 stars. Messier 2 is one of the oldest globular clusters; its age is estimated to be 13 billion years.

Comets

Comet C/2008 A1 McNaught becomes visible after Thursday. It moves northward in constellation Libra toward Ophiuchus. It is reported to be magnitude 7 in brightness and coma is 10 arc min across.

C/2007 N3 Lulin is in constellation Ophiuchus and is magnitude 10.7

C/2007 W1 Boattini is in constellation Pisces magnitude 10.6

6P d'Arrest is in constellation Grus (below Aquarius). Look straight south around 10:30 pm. magnitude +8.5

C/2006 W3 Christensen is in constellation Cassiopea 11.7

C/2006 OF2 Broughton is in Camelpardus 11.1

C/2008 J1 Boattini 11.5 is in constellation Camelpardalis 17P Holmes is in constellation Cancer It is a large faint diffuse object 1-2 degrees across and about magnitude 6.1, it will be very tough to see, use binoculars.

19P Borrelly is in constellation Leo Minor magnitude 11.3

International Space Station

The best pass this week for the Denver area is on Sat. Oct 4. Look for ISS low in north-northwest at 7:48 pm. It will disappear into the earth's shadow in the northeast at 7:51 pm MDT. It will reach -0.8 in brightness.

There is a bright pass next Sunday, Oct. 11. Look for the ISS low in the northwest at 8:14 pm mdt. It will disappear into the earth's shadow in the north-northwest at 8:16 pm mdt. It will reach magnitude -1.6 on that pass.

The times that the ISS is visible varies quite a bit depending on your location. If you are not in the Denver area, please check www.heavens-above.com for specific times.

Summary

This week you can watch the International Space Station fly over, see a very old crescent moon, and enjoy the beauty of earthshine on the moon. Get our your telescope watch Jupiter's great red spot transit the disk, locate some dim comets, and view one of the oldest and compact globular clusters in our Milky Way galaxy, Messier 2.