Smashing comets and spectacular scorpions: Heather Couper and Nigel Henbest scan the July skies to preview a lunar anniversary, a collision on Jupiter and a constellation with a sting in its tail

It looks like being quite a month for space. First, over a six-day period between 16 and 22 July, the shattered remains of Comet Shoemaker-Levy will hit the planet Jupiter. As luck would have it, all the impacts will take place on the side of Jupiter that is turned away from Earth. But as Jupiter spins so rapidly (its 'day' is less than 10 hours long), scientists are hopeful that we may see something of the aftermath when the impact sites swing into view.

The biggest collision, with a fragment estimated to be 4km across, will coincidentally take place on the 25th anniversary of the other space event that will be celebrated this month - the first manned Moon landing. Among all the nostalgia and reminiscing, there will doubtless be a look to the future - and a call for us to return to the Moon.

But we have already begun our return. Earlier this year, on 19 February, an American spacecraft called Clementine slipped into lunar orbit. For more than two months it surveyed the whole Moon, including some regions near the poles that have never been mapped before (where it may have discovered ice pockets deposited by comets). The 1.6 million images it obtained at different wavelengths reveal the Moon's geology in unprecedented detail, with its various soil and rock types picked out in 11 colours. These images, which are widely available in the US on the Internet, will help in planning future lunar exploration, and, eventually, in exploiting the Moon's mineral resources.

Clementine is a new breed of spacecraft. A collaboration between the National Aeronautics and Space Administration (Nasa) and the US Department of Defense, it was designed and built in under two years with the cheap price-tag (for a space probe) of dollars 55m ( pounds 36m). It is a test of new technologies - in particular, lightweight sensors and electronics - that could be used for both military and civil applications. Ironically, it was old technology - in the shape of the computer - that prematurely ended Clementine's mission.

After leaving lunar orbit, the probe had been scheduled to rendezvous in late August with the near-Earth asteroid 1620 Geographos. But a computer malfunction triggered the 12 attitude-control thrusters to vent all their hydrazine propellant, leaving the spacecraft unsteerable. Despite this, the Clementine mission has been judged an outstanding success, and Clementine 2 is now on the drawing board.

The planets

Venus is still a brilliant object in the north-western sky after sunset, although by the end of the month it sets only an hour and a half after the Sun. On 12 July, it forms a pretty grouping with the crescent Moon. The other planet prominent in evening skies is Jupiter, although by the end of the month it will set at about midnight. Readers with access to moderate or large telescopes (with apertures of at least 15cm) might like to monitor the planet between 16-22 July to see if the Comet Shoemaker-Levy's impacts have any effect on Jupiter's vast bulk.

Saturn is now starting to put on an appearance in evening skies, rising at about 10.30pm mid-month. The remaining planets visible to the unaided eye - Mars and Mercury - are both morning objects. Mars is rising at about 2am, and is currently tracking past the stars of Taurus. Mid-month it passes close to the bull's 'eye', Aldebaran (which is slightly brighter than Mars and almost as red), and the Pleiades star cluster. On the morning of 5 July, it will make a striking grouping with the Moon, with the latter less than a moon's width to the south.

Mercury is a morning star this month. It rises with the Sun at the beginning of July, but gradually draws away until mid-month, when it rises an hour before the Sun.

The stars

This month affords the best view of one of the most spectacular constellations in the sky: Scorpius. Seen from more southerly latitudes, it is an unforgettable sight: a huge Scorpion-shaped curve of stars, with a vicious-looking sting in its tail. In Britain we are too far north ever to see the tail, so much of the effect is lost. But we can see the heart - the star Antares - and the 'pincers', low in the south.

In mythology, Scorpius was the scorpion whose sting killed Orion. The two constellations are on opposite sides of the sky, apparently a deliberate ploy by the gods to keep them apart. It is one of the most ancient of all constellations, dating back to 5,000 BC when it was one of the six original zodiacal signs of the Euphratean astronomers. The constellation's brightest star is Antares, whose name stems from the Greek 'Anti-Ares' - rival of, or similar to, Mars. It is a red giant star close to the end of its life, and changes slightly in brightness as its loosely held atmosphere pulsates in and out. Recent estimates of its size - almost one billion kilometres across - make Antares nearly as large as Betelgeuse, its counterpart in Orion.

Scorpius harbours an object that gave rise to a whole new field of astronomy. Close to the borders with Ophiuchus is Scorpius X-1, a faint double star with strange characteristics. As well as giving out light, it emits powerful X-rays, which were detected serendipitously on a routine flight by an Aerobee rocket in 1962. The X-rays come from fiercely hot gas dragged from one star of the pair on to the other - probably a neutron star with an immense gravitational pull.

Since the discovery of Scorpius X-1 - still the brightest X-ray source known - thousands of other X-ray sources have been pinpointed by rockets and satellites (fortunately, X-radiation does not penetrate Earth's atmosphere). Most, like Scorpius X-1, are regions of extreme cosmic violence, and some may even be the environs of black holes.

Diary (all times BST)

5 July Earth farthest from Sun (152m km)

8 10.38pm, New Moon

16 2.12am, Moon at First Quarter

17 Mercury at greatest W elongation

22 9.16pm Full Moon

30 1.40pm Moon at Last Quarter

(Maps omitted)

Suggested Topics
Start your day with The Independent, sign up for daily news emails
i100 In this video, the late actor Leonard Nimoy explains how he decided to use the gesture for his character
Arts and Entertainment
Secrets of JK Rowling's Harry Potter workings have been revealed in a new bibliography
arts + ents
Down-to-earth: Winstone isn't one for considering his 'legacy'
ebooksA special investigation by Andy McSmith
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Sauce Recruitment: Retail Planning Manager - Home Entertainment UK

salary equal to £40K pro-rata: Sauce Recruitment: Are you available to start a...

Ashdown Group: Front-End Developer - London - up to £40,000

£35000 - £40000 per annum: Ashdown Group: Creative Front-End Developer - Claph...

Recruitment Genius: Product Quality Assurance Technologist - Hardline & Electric

£18000 - £24000 per annum: Recruitment Genius: The role in this successful eco...

Ashdown Group: QA Tester - London - £30,000

£28000 - £30000 per annum: Ashdown Group: QA Tester - London - £30,000 QA Tes...

Day In a Page

HIV pill: Scientists hail discovery of 'game-changer' that cuts the risk of infection among gay men by 86%

Scientists hail daily pill that protects against HIV infection

Breakthrough in battle against global scourge – but will the NHS pay for it?
How we must adjust our lifestyles to nature: Welcome to the 'Anthropocene', the human epoch

Time to play God

Welcome to the 'Anthropocene', the human epoch where we may need to redefine nature itself
MacGyver returns, but with a difference: Handyman hero of classic 1980s TV series to be recast as a woman

MacGyver returns, but with a difference

Handyman hero of classic 1980s TV series to be recast as a woman
Tunnel renaissance: Why cities are hiding roads down in the ground

Tunnel renaissance

Why cities are hiding roads underground
'Backstreet Boys - Show 'Em What You're Made Of': An affectionate look at five middle-aged men

Boys to men

The Backstreet Boys might be middle-aged, married and have dodgy knees, but a heartfelt documentary reveals they’re not going gently into pop’s good night
Crufts 2015: Should foreign dogs be allowed to compete?

Crufts 2015

Should foreign dogs be allowed to compete?
10 best projectors

How to make your home cinema more cinematic: 10 best projectors

Want to recreate the big-screen experience in your sitting room? IndyBest sizes up gadgets to form your film-watching
Manchester City 1 Barcelona 2 player ratings: Luis Suarez? Lionel Messi? Joe Hart? Who was the star man?

Manchester City vs Barcelona player ratings

Luis Suarez? Lionel Messi? Joe Hart? Who was the star man at the Etihad?
Arsenal vs Monaco: Monaco - the making of Gunners' manager Arsene Wenger

Monaco: the making of Wenger

Jack Pitt-Brooke speaks to former players and learns the Frenchman’s man-management has always been one of his best skills
Cricket World Cup 2015: Chris Gayle - the West Indies' enigma lives up to his reputation

Chris Gayle: The West Indies' enigma

Some said the game's eternal rebel was washed up. As ever, he proved he writes the scripts by producing a blistering World Cup innings
In Ukraine a dark world of hybrid warfare and murky loyalties prevails

In Ukraine a dark world of hybrid warfare

This war in the shadows has been going on since the fall of Mr Yanukovych
'Birdman' and 'Bullets Over Broadway': Homage or plagiarism?

Homage or plagiarism?

'Birdman' shares much DNA with Woody Allen's 'Bullets Over Broadway'
Broadchurch ends as damp squib not even David Tennant can revive

A damp squib not even David Tennant can revive

Broadchurch, Series 2 finale, review
A Koi carp breeding pond, wall-mounted iPads and a bathroom with a 'wellness' shower: inside the mansion of Germany's 'Bishop of Bling'

Inside the mansion of Germany's 'Bishop of Bling'

A Koi carp breeding pond, wall-mounted iPads and a bathroom with a 'wellness' shower