Monthly Skywatchers' Page

For London and the UK

Sun And Nine Planets
The Sun and eight major planets (plus KBO Pluto) to scale. Earth is third planet from the left.


Introduction

The location of the stars and constellations can be learnt throughout a single year from books, mobile phone applications or planetarium software. Each month of the year, the same stars are visible from a given location. Different stars and constellations are visible as the year progresses. For example, in London, the constellation of Orion is always visible in the evenings of winter months of January and February. Scorpius is visible in the summer months of June and July around midnight.

The planets resemble stars except that, generally, they do not twinkle. Unlike the stars whose patterns are fixed, planets wander through the sky changing their positions amongst the starry background. This means that their periods of visibility change as the relative position of the Earth, Sun and planet vary. In one year Mars may be visible in August at midnight. In another year it may be behind the Sun and invisible from Earth during August.

This page gives the details of visibility for the five naked eye planets: Mercury, Venus, Mars, Jupiter and Saturn. It also gives information about comets, meteor showers and non-regular phenomena like eclipses, transits and occultations.

The Observers' Glossary explains the terms used. Alternatively run the mouse cursor over terms in maroon.


The descriptions below are for viewers in the Northern Hemisphere, especially London and the United Kingdom.
The planetary information is valid for any location at the same or similar Latitude (51.5°N).
Note that a degree in the sky is twice the apparent diameter of the Moon.

All times on this page are London (UK) times. This is normally GMT (Greenwich Mean Time also known as Universal Time).
In the United Kingdom, the clocks go forward by one hour for British Summer Time (BST) between mid March and late October.
A 24 hour clock is used so that 7pm is written 19:00.


August 2018

Mercury

Mercury

Mercury passes through inferior conjunction on 9th.

The planet quickly moves away from the Sun to become visible as a morning object to the North of East about an hour and a half before sunrise for the last ten days of August. Mercury brightens towards the end of the month.

This is the best morning appearance of the elusive inner planet.

Venus

Venus

Venus is visible in the West as a brilliant evening object, fourteen times brighter than the brightest star. The planet sets about an hour and a half after sunset at the beginning of August.

Venus is in Virgo and will be seen close to the crescent Moon on 14th.

The planet is getting lower in the sky and becoming harder to see. By the end of the month Venus will be setting just an hour after sunset.

Mars

Mars

Mars was at opposition on 27 July.

The planet is moving retrograde among the stars of Capricornus moving into Sagittarius on 24th. Mars is now an evening object visible in the South East as the sky darkens.

For the whole of August, Mars will be brighter than Jupiter but is now fading as it moves away from the Earth.

The red colour of Mars will be very noticeable to the naked eye.

Mars can be seen just below the Moon on 23rd.

Jupiter

Jupiter

Jupiter is a bright evening object setting three hours after the Sun among the stars of Libra at the beginning of the month.

The planet is close to the Moon on 17th.

Through a small telescope, the planet's four large moons can easily be seen. They resemble little stars, changing positions from night to night.

By the end of August, Jupiter will be moving into the evening twilight and will be setting a couple of hours after the Sun.

Saturn

Saturn

Saturn is an evening yellow star-like object among the stars of Sagittarius setting after midnight at the beginning of August and just before midnight by the end of the month.

Look for the planet on the 20th and 21st when it will be close to the Moon.

During 2018, Saturn will be low in the sky as it is now at its furthest south in its 30 year cycle.

Through a telescope the magnificent rings are easy to see and this year they are at an open angle. If you have access to a telescope, use the Moon to locate Saturn and look at it through a telescope on a clear night. The sight of the rings is one of the best views in the sky. During 2018, we are looking down onto the planet's North Pole so the rings appear to be wide open. The rings are open wide every fifteen years.

Sun

The Sun

The Sun continues to move south which causes the days to get shorter, now at a gathering pace. On 1st August the length of day is 15 hours 24 minutes. This decreases to 13 hours 38 minutes by the end of the month, a decrease of nearly two hours.

During August the time of midday (when the Sun is due South and at its highest in the sky) is just after 13:00 (remember the clocks went forward in March) until the final day of the month.

The Sun begins the month in Cancer and enters Leo on 10th.

Note that the Zodiac dates do not tie in with astrology as astrologers are using dates from two thousand years ago.

Date Sunrise Midday Sunset Length of Day Sun's Noon Altitude Notes
01-Aug
05:24
13:06
20:48
15h 24m
56.5°
 
02-Aug
05:25
13:06
20:46
15h 21m
56.2°
 
03-Aug
05:27
13:06
20:45
15h 18m
55.9°
 
04-Aug
05:28
13:06
20:43
15h 15m
55.7°
Morning Half Moon
05-Aug
05:30
13:06
20:41
15h 11m
55.4°
 
06-Aug
05:31
13:06
20:40
15h 08m
55.1°
 
07-Aug
05:33
13:06
20:38
15h 05m
54.9°
 
08-Aug
05:34
13:06
20:36
15h 01m
54.6°
15 hour day
09-Aug
05:36
13:06
20:34
14h 58m
54.3°
 
10-Aug
05:37
13:05
20:32
14h 54m
54.0°
 
11-Aug
05:39
13:05
20:30
14h 51m
53.7°
New Moon at 09:58 (Leo) - Partial Eclipse of the Sun (not London)
12-Aug
05:41
13:05
20:28
14h 47m
53.4°
Perseid Meteor Shower Maximum
13-Aug
05:42
13:05
20:27
14h 44m
53.1°
Perseid Meteor Shower Maximum
14-Aug
05:44
13:05
20:25
14h 40m
52.8°
Moon close to Venus
15-Aug
05:45
13:04
20:23
14h 37m
52.5°
 
16-Aug
05:47
13:04
20:21
14h 33m
52.2°
 
17-Aug
05:48
13:04
20:19
14h 30m
51.8°
Moon close to Jupiter
18-Aug
05:50
13:04
20:17
14h 26m
51.5°
Evening Half Moon
19-Aug
05:52
13:04
20:15
14h 22m
51.2°
 
20-Aug
05:53
13:03
20:12
14h 19m
50.9°
Moon close to Saturn
21-Aug
05:55
13:03
20:10
14h 15m
50.5°
Moon close to Saturn
22-Aug
05:56
13:03
20:08
14h 11m
50.2°
 
23-Aug
05:58
13:03
20:06
14h 08m
49.9°
Moon close to Mars
24-Aug
06:00
13:02
20:04
14h 04m
49.5°
6am sunrise
25-Aug
06:01
13:02
20:02
14h 00m
49.2°
14 hour day
26-Aug
06:03
13:02
20:00
13h 56m
48.8°
Full Moon at 11:56 (Aquarius) - 8pm sunset
27-Aug
06:04
13:02
19:58
13h 53m
48.5°
 
28-Aug
06:06
13:01
19:55
13h 49m
48.1°
 
29-Aug
06:08
13:01
19:53
13h 45m
47.8°
 
30-Aug
06:09
13:01
19:51
13h 41m
47.4°
 
31-Aug
06:11
13:00
19:49
13h 38m
47.1°
Noon at 1pm

Moon

The Moon

The Moon will be close to Venus on 14th.

The Moon will be close to Jupiter on 17th.

The Moon will be close to Saturn on 20th and 21st.

The Moon will be close to Mars on 23rd.

Meteor Shower

The Perseid meteor shower reaches its peak on the night of the 12th-13th (around 2am). This year the Moon will be New on 11th so will not interfere.

Look towards the North East towards midnight for a few days on either side of this date.

Shooting stars should be visible for a few days on either side of the maximum date.

Look between the zenith (overhead point) and the North East after 22:00 and wrap up well. At its best this annual shower should provide about one shooting star per minute.

Sun

Solar Eclipse

A partial eclipse of the Sun occurs on 11th. This will be visible in Northern Europe, Siberia, Greenland and China.

The only part of the UK that will see the eclipse is the extreme North of Scotland. The eclipse is not visible from England.


It is easy to depend on astronomy or CMMS software to perform daily computational activities and to keep track of data. Astronomy enthusiasts can choose from a wide variety of software options, while facility managers may have fewer options if they require CMMS software for their business.


Next Month

Mars, Saturn and Jupiter in the evening. Mercury in the morning. Equinox.


All times on this page are London (UK) times.

Sources: Astronomy Now magazine, Cybersky, Starry Night Pro, USA Naval Observatory and UK Nautical Almanac Office.

© 2018 KryssTal
All sky images by Starry Night Pro Plus 6
Eclipse predictions (maps) courtesy of Fred Espenak, NASA's GSFC


Books From Amazon.co.uk


Observers' Glossary

An explanation of the terms used by sky observers. Includes descriptions of how the objects of the solar system behave in the sky as seen from Earth (especially the Northern Hemisphere high latitudes).


KryssTal Related Pages

Tables and data about the Sun, Earth, Moon, planets, asteroids and comets. All terms used are explained.

An account of how various properties of stars can be measured by studying starlight. Includes brightness, distance, luminosity, temperature, mass, radius, density and an introduction to the H-R Diagram.

A table containing a list of the 20 brightest stars in the Earth's sky. Explanations of all the associated terms like magnitude, spectral type and radial velocity.

A detailed account about eclipses, transits and occultations. These are irregular phenomena that can be observed in the sky. Includes eclipse trips around the world with photos and well as photos of recent transists of Mercury and Venus.

An easy-to-understand scaling of the Universe in space. Distances in space are represented by the time light takes to travel there.

An easy-to-understand scaling of the Universe in time. The chronology of the Universe is compared to a real year.

How humanity came from believing Creation Myths to postulating the Inflationary Big Bang Theory. The key stages in our understanding of our place in the cosmos and the people who broadened our understanding.

What do we mean by the words day, week, month, year? Who invented our calendar? When did the third millennium begin? The relation between time and astronomy.

The force that moves apples and planets. A short introduction to the ideas of Kepler and Newton that culminated with the theory of Universal Gravitation.

A look at the mathematics of a sphere with a section on sundials and the equation of time.


External Skywatching Links

These links will open in a separate window

StarDate Online
An excellent online skywatchers' magazine featuring detailed monthly information about astronomical events.

Astronomy Picture of the Day
A different image each day with an extensive archive and explanations.

Society for Popular Astronomy
Monthly planet and star gazing details with maps for young people.

Telescope House
A London based source of astronomical equipment, telescopes, software, maps and books.

Southern Sky Watch
Sky watchers information for the southern hemisphere.

Starry Night Pro
Superb planetarium software. Simulate the sky from anywhere on the Earth and any time.