SkyEye

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

October 2010

Date 45° N 30° S Event
1 Fri Saturn at conjunction
Last Quarter Moon
2 Sat
3 Sun
4 Mon
5 Tue
6 Wed Perigee
7 Thu New Moon
8 Fri Moonless skies make this an excellent year for observing the Draconids (theoretical peak activity: from 15:00 UT until 07:30 UT tomorrow).
9 Sat
10 Sun
11 Mon
12 Tue
13 Wed
14 Thu First Quarter Moon
15 Fri
16 Sat
17 Sun Mercury at superior conjunction
18 Mon Apogee
19 Tue
20 Wed
21 Thu The nearly full Moon obliterates the Orionids.
22 Fri
23 Sat Full Moon
24 Sun
25 Mon
26 Tue
27 Wed
28 Thu 103P Hartley 2 at perihelion
29 Fri Venus at inferior conjunction
30 Sat This is the second Last Quarter Moon to occur this month.
31 Sun

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 like comets are not so constrained, often moving far above or below the ecliptic.

Sun
Virgo » Libra
Mercury
Virgo » Libra
The smallest planet in the solar system is largely lost in solar glare at the beginning of the month, with superior conjunction occurring on 17 October. It reappears low in the west after sunset at the end of the month.
Venus
Libra » Virgo
The "evening star" is quite low as seen from northern latitudes but is quite high in the west early in the month for southern hemisphere observers. It soon plummets toward the horizon and its date with the Sun (inferior conjunction) on 29 October.
103P/Hartley 2
Cassiopeia » Perseus » Camelopardalis » Perseus » Auriga » Gemini » Monoceros
This comet was discovered in 1986 by Malcolm Hartley at the Siding Spring Observatory. It has a period of 6.4 years and its perihelion distance is just over 1 AU. This year's return is a very favourable one, with perihelion occurring just eight days after closest approach to Earth, and should be at least magnitude 4 or 5. The comet appears in Auriga at closest approach and near the star mu Geminorum at perihelion. Interestingly, the Deep Impact spacecraft, which visited comet 9P/Tempel 1 in July 2005, will rendezvous with this comet next month.
Mars
Libra » Scorpius
It is getting increasingly difficult to see this planet low in the west during evening twilight.
Jupiter
Pisces » Aquarius
The largest planet in the solar system was at opposition last month, so it is still visible for most of the night, setting before sunrise.
Saturn
Virgo
The ringed planet is at conjunction on the first of the month, reappearing low in the east at sunrise by the end of the month.
Uranus
Pisces
At opposition last month, this green-coloured gas giant sets before dawn.
Neptune
Capricornus
A small telescope is necessary to view the most distant planet in the solar system which sets just after midnight.

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...

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 SkyEye banner features a collision of galaxy clusters and is courtesy of NASA, ESA, CXC, M. Bradac (University of California, Santa Barbara) and S. Allen (Stanford University). When MACS J0025.4-1222 was formed, gravity caused the ordinary matter in the colliding galaxy clusters to slow down whereas the dark matter, which at best interacts only weakly with itself, continued on its original course. Thus, this object provides both confirmation of the existence of dark matter and a further understanding of its properties. This image is a composite of Hubble Space Telescope and Chandra X-ray Observatory data where dark matter is coloured blue (mapped by Hubble using gravitational lensing techniques) and ordinary matter is coloured pink (mapped by Chandra detecting X-rays from gas heated by the collision).


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Last modified on 30 September 2010