See Calendars at: Astronomical Events - Discover Eclipses, Meteor Showers, ... (space.about.com) | Central Coast Astronomical Society - CCAS,
Astronomical Calendar 2004, by Guy Ottewell.

• 2005 April 8 - Total solar eclipse visable in a populated area:
  Total eclipse visible from northern South America (Venezuela, Columbia, Panama). Partial visible from southern US and western South America. (see map (PDF))
  
• 2004 May 4 - Total Lunar eclipse - Visible in Asia, Europe except western region, Africa except northwestern part, Indonesia, Australia, New Zealand, the eastern South Atlantic Ocean, the Indian Ocean, and the western Pacific Ocean;
• 2004 October 28 - Total Lunar eclipse - The beginning of the umbral phase visible in Africa, Europe, Greenland, the Arctic region, North America except the extreme northwest, Central America, South America The end visible in North America, the Arctic region, Greenland, Central America, South America, Europe.

Comets
A relatively small object which is composed of dirt and ices. Comets are characterised by dust and gas tails pointing away from the sun. The ones that we have seen have large elipitical orbits extending to the outer solar system and beyond. They range in size from 1/2 to 5 mi. Astronomers estimate there are 100 billion of these objects in the Oort Cloud beyond Pluto.

A comet's apparent brightness as seen from Earth depends on both its distance from the Sun and its distance from Earth. A comet may seem brighter on one appearance than another because of the position of the earth in its orbit brings it closer to the comet. A comet also grows brighter as it comes closer to Sun and its water and ice vaporizes ever more vigorously.

Name	Last	Next (Perihelion)	Magnitude
2P/Encke	2000	2003 December 29	4
C/2002 T7 (LINEAR)		2004 April 23	1-2
C/2003 T3 (Tabur)		2004 April 28	8
C/2001 q4 (NEAT)		2004 May 15	1-2
C/2003 K4 (LINEAR)		2004 October 13	5-6
Halley	1986	2061
Chiron (2)	1996	2046
C/1996 B2 (Hyakutake)	1996	10-18,000 (3)
Hale-Bopp	1997	5500
Tempel-Tuttle	1998	2031
Swift-Tuttle	1992	2122
Thatcher	1861	2276

Source: www.stargazer7.freeservers.com/custom.html
(2) Chiron is categorized as both an Asteroid and Comet.

(3) Calculations indicate Hyakutake original period was close to 10,000 yrs. and the future period will be about 18,000 years due to perturbations by planets during the present passage.

Fragments of Comet Shoemaker-Levy 9 collided with Jupiter between July 16 and July 22, 1994.

Periodic or short-period comets: Any comet with an orbital period of less than 200 years. These comets are indicated by a "P/" before the names. For example, P/Halley is Halley's comet or more properly known as periodic Comet Halley.

See: Gary W. Kronk's cometography.com
http://seds.lpl.arizona.edu/billa/tnp/comets.html at U. of Arizona
Comets currently Visable and Great Comets in History at NASA.
www.astronomysight.com/as/info/comets.html.
Comets, Meteors, And Asteroids by Nalin Singal.

Meteor Showers
An average of 7 sporadic (not associated with a shower) meteors per hour can be seen from one place on a normal clear night. 200 million visible meteors reach the earth each day. (Source: The Astronomical Companion, by Guy Ottewell)

A meteor shower is caused by a trail of particles left by a comet as it revolves around the Sun or a broken up asteroid. These particles can remain suspended in space for decades. Meteor showers produce 50 or more visible meteors per hour. The Perseids were one of the most exciting meteor showers during the 1990s, with outbursts of 400+ meteors per hour in 1991 and 1992. Rates from this peak decreased to 100-120 by the late 1990s, and since 2000, it has failed to appear.

Most meteors from a common meteor shower are parallel to one another. But they appear to emerge from the same point in the sky called the "radiant" and they travel in all directions from this point.

The friction between the meteor and earth's atmosphere, generates enough heat (up to 3,000 degrees Fahrenheit, or 1649 degrees Celsius) to raise the meteoroid's surface to its boiling point, so the meteoroid is vaporized, layer by layer, creating a vapor of sodium, iron and magnesium atoms. In subsequent collisions, electrons are knocked into orbits at larger mean distances from the nucleus of the atoms. When the electrons fall back to their rest positions, light is emitted. This is the same process as in gas discharge lamps.

The main meteor showers in 2007 are:

Name	Dates	ZHR *	Comet	Period Yrs	Next
Quadrantids (QUA)	1 to 5 of January	120	2003 EH1 †	5-7
Lyrids (LYR)	16 to the 25 of April	15	Thatcher	415	2276
Eta-Aquarids (ETA)	April 19 to May 28	60	Halley	75	2061
Southern Delta-Aquarids (SDA)	July 12 to August 19	20	unknown
Orionids (ORI)	Oct 2 to Nov 7	23	Halley	75	2061
Perseids (PER)	July 17 to August 24	100	Swift-Tuttle	130	2122
Leonids (LEO)	10 to 23 of November	15+ (1)	Tempel-Tuttle	33.2	2031
Geminids (GEM)	7 to 17 of December	120	Asteroid Phaethon	1.4
Taurids	Nov	10	Encke	3.3	2010
Ursids (URS)	17 to 26 Dec	10	8P/Tuttle	13.5	2008

* ZHR: Zenithal Hourly Rate - a calculated maximum number of meteors an ideal observer would see in perfectly clear skies with the shower radiant overhead.

1. ZHR for Leonids in 1998 just after the Tempel-Tuttle comet passed was several hundred.
(Note: Hourly Rate (ZHR) will drop off over time until the comet that left the particles reappears. This can be from a few years to hundreds of years.)

† It was only recently speculated that comet 2003 EH1 was responsible for the Quadrantids meteor shower. The orbit of this comet seems to vary over time due to encounters with Jupiter or an asteroid.

Links:
Viewing Tips at StarDate.org
Perseid Meteor Shower

2007 Meteor Shower Calendar at IMO

Sky Watch, The International Meteor Organization - IMO,
and The Central Coast Astronomical Society - CCAS
Meteor Showers List at popastro.com
Annual Meteor Showers: Where and When to Look at StarGazing.suite101.com

Asteroids
There are 30-40,000 of these giant rocks floating in their own individual orbits between Mars and Jupiter. There are several hundred known asteroids that regularly cross the orbit of the Earth. They are known as Earth-crossing asteroids. They range in size from 1 to 600 miles (1/4 the size of our moon). Smaller objects are called meteoroids.

• 2003 Hermes is an asteroid with an orbit that brings it into the inner solar system. Orbital Period is about 2 yrs. Last visit was Nov. 4, 2003.
• On Monday, 12 February 2001, the NEAR spacecraft touched down on asteroid Eros
• Ceres is large enough to be viewed with binoculars at certain times.
• Asteriods may be the remnants of larger "planetoids" that collided with each other between the orbits of Mars and Jupiter.

See: Potentially Hazardous Asteroids (PHAs) at the Asteroids page.

Planets
Five planets (The 3 inner planets, Mercury, Venus and Mars, plus the first two outer planets, the gas giants, Saturn and Jupiter) are visible with the naked-eye.

What many people call the morning or evening star is actually a planet, usually Venus but sometimes Jupiter, Saturn, or Mars. When one of them appears close to the Sun as viewed from Earth, sunset or sunrise watchers are treated to starlike brilliance.
A planet might be a "morning star" at one time of the year and "evening star" at other times.

Mars:
Every twenty-six months, the Earth passes between Mars and the sun. Astronomers call this moment "opposition" because, as seen from Earth, Mars lies opposite the sun in the sky. This is the time when Mars lies closest to us, shines at its brightest and appears largest in a telescope.

Because Mars orbit is slightly eliptical it may be closer some years. On August 27, 2003 Mars was closer to the earth than at any time in the past 60-70,000 years. See www.spaceweather.com/delights/mars2003_View.html

On June 8, 2004 venus' orbit took it between the earth and sun.

See:
Mars 2003
users.gsat.net.au/astronet/planets.html
Glossary for planets
The nine planets at U. Arizona
Planet Visibility

Man-made Objects (Satellites, Space Shuttle, Space Station)
Large satellites, e.g. The International Space Station (ISS) and The Space Shuttle and some with relatively low orbits e.g. Iridium satellites, can be seen with the naked eye or with the aid of binoculars.

See:
j-Pass at NASA
SatPasses - Satellite Passes Over North American Cities at bester.com.
Heavens-Above

Galaxy Collision
6 billion years or so from now our Milky Way Galaxy and our neighboring Andromeda galaxy may collide. Galaxies are mostly empty space (the nearest star to the sun is 4 light years away), so there will not be a lot star/planet collisions.
See: hubblesite.org/newscenter/newsdesk/archive/releases/2002/09/