SkyEye

Welcome to SkyEye, your guide to this month's celestial events.

January 2008

All times and dates are given in Universal Time (UT).
Nightly darkness estimates are calculated for 45° N and 30° S.
Like total solar eclipses, lunar occultation events can be seen only from limited regions on Earth (and sometimes not at all if the occultation takes place during daylight hours). However, the Moon will appear close in the sky to its "target" for some hours either side of the actual occultation, regardless of where you are.

Date		Event
1	Tue
2	Wed
3	Thu	Earth at perihelion
3	Thu	Moon at apogee
4	Fri	After being washed out by a nearly Full Moon in 2007, the Quadrantid meteor shower appears in dark skies this year. The estimated peak is 06:00 UT.
5	Sat	Moon occults first-magnitude star Antares: visible from parts of the western side of South America at around 10:00 UT.
6	Sun
7	Mon
8	Tue	New Moon
9	Wed	Moon occults Mercury: visible from central Africa at around 16:00 UT.
10	Thu
11	Fri
12	Sat
13	Sun
14	Mon
15	Tue	First Quarter Moon
16	Wed
17	Thu
18	Fri
19	Sat	Moon at perigee
19	Sat	Moon occults Mars: visible from northwestern North America and the Arctic at around 05:00 UT.
20	Sun
21	Mon
22	Tue	Mercury at greatest elongation east
22	Tue	Full Moon
23	Wed
24	Thu	Moon occults first-magnitude star Regulus: visible from Indonesia, Australia and New Zealand at around 15:00 UT.
25	Fri
26	Sat
27	Sun	8P/Tuttle at perihelion
28	Mon
29	Tue
30	Wed	Last Quarter Moon
31	Thu	Moon at apogee

The Solar System

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. Dwarf planets and small solar-system bodies, including comets, are not so constrained, often moving far above or below the ecliptic.

Sun: Sagittarius -> Capricornus
The Earth makes its annual closest approach to the Sun on 3 January. The date of perihelion can range from New Year's Day to 4 January.
Mercury: Sagittarius -> Capricornus
The closest planet to the Sun is an evening sky object, rising high in the southwest for northern hemisphere observers but not so well-placed for viewers in the southern hemisphere. It is occulted by the Moon on 9 January and reaches greatest elongation east on 22 January. On 14 January, the MESSENGER spacecraft will make its first fly-by of this mysterious world.
Venus: Libra -> Scorpius -> Ophiuchus -> Sagittarius
The "morning star" is slowly descending towards the eastern horizon for the first five months of this year. It appears slightly higher in the sky when viewed from the southern hemisphere than from the north.
8P/Tuttle: Pisces -> Aries -> Pisces -> Cetus -> Fornax -> Eridanus
This comet will pass particularly close to the Earth on this apparition, coming to within 0.25 AU early in the month. It will be visible in binoculars and may be a naked-eye object for observers with very dark skies. It is best viewed from the northern hemisphere but will be visible to those in the southern hemisphere by the end of the month. It reaches perihelion on 27 January.
Mars: Taurus
The red planet was at opposition late last month which means it is up most of the night.
17P/Holmes: Perseus
Normally invisible to the naked eye, 17P/Holmes unexpectedly became many magnitudes brighter on 24 October, reaching third magnitude. Discovered by London observer Edwin Holmes on 6 November 1892, the comet has a period of approximately 7 years and spends its time between the orbits of Mars and Jupiter, last reaching perihelion in May 2007. To find the comet, look for a faint fuzzy "extra star" moving past Algol (beta Persei) late in the month.
Jupiter: Sagittarius
The largest planet in the solar system is also a morning sky object, finally emerging out of the Sun's glare and rising past Venus by the end of the month.
Saturn: Leo
The ringed planet is at opposition next month and thus is up most of the night. It rises in mid-evening and is best viewed in the early hours of the morning.
Uranus: Aquarius
The most distant of the naked-eye planets undergoes conjunction in March so it is getting difficult to see in the western sky, setting by mid-evening.
Neptune: Capricornus
A small telescope is necessary to view the most distant planet in the solar system. However, with conjunction approaching early next month, it is probably too close to the Sun to observe.

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union (IAU) recognises 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 summer (daylight savings) time is in effect.

Local Time	Northern Hemisphere	Southern Hemisphere
1730 hours (1830 hours summer time)	45° N	30° S
1930 hours (2030 hours summer time)	45° N	30° S
2130 hours (2230 hours summer time)	45° N	30° S
2330 hours (0030 hours summer time)	45° N	30° S
0130 hours (0230 hours summer time)	45° N	30° S
0330 hours (0430 hours summer time)	45° N	30° S
0530 hours (0630 hours summer time)	45° N	30° S

For More Information...

Consult our online glossary for non-technical explanations of many of the astronomical terms used in these pages.
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 your favourite amateur astronomy magazine 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 variable star V838 Monocerotis in the SkyEye banner is courtesy of NASA, ESA and the Hubble Heritage Team (STScI/AURA). Located 20,000 light years away in the constellation of Monoceros, V838 Mon temporarily brightened in early 2002. The reason for this outburst is not understood. The resulting light echo, the light from the stellar explosion illuminating the dust surrounding the the star, was captured by the Hubble Space Telescope in October of that year.