Astronomers baffled by biggest comet's lack of impact: Collision with the planet Jupiter causes burst of light and heat, but soon recedes compared to previous impacts, writes Susan Watts

ASTRONOMERS are baffled by the modest impact of what they had identified as being the biggest chunk of comet Shoemaker-Levy 9, which dive-bombed into Jupiter's frozen atmosphere on Wednesday evening.

Observers said yesterday that they had expected the crash of fragment Q1 to be the most dramatic yet. Instead, after a promising initial burst of light and heat lasting about 10 minutes, it soon paled beside earlier impacts. After a few hours, the dark scar it left on the planet's surface had all but disappeared.

Fragment Q1 was the first of a clump of three large chunks in the series of 21 expected to hit Jupiter in quick succession at almost the same spot. Yesterday, fragment R appeared to have landed on target - very close to the still-glowing impact zone of Q1. Astronomers in South Africa reported seeing the impact site of fragment S, twice as bright as Q1 and visible for about 15 minutes.

A ring of blotches, some formed by collisions several days ago, is still clearly visible from ground-based telescopes, although it is now beginning to dim. Fragments G and L, which hit on Monday and Tuesday evenings, are thought to have caused the biggest wounds so far.

Astronomers at the Royal Greenwich Observatory in Cambridge said Q1 may have been smaller than they thought, or more 'floppy' so it disintegrated as it approached Jupiter.

Alternatively, Q1 may have been far more dense than anticipated, and plunged deeper into the Jovian atmosphere before exploding - causing a less visible plume than explosions closer to the surface. However, astronomers said they would have expected the scar to have been bigger and longer-lasting if this were the case.

Four fragments crashed into the planet yesterday - the remaining two of the close-packed trio and, in the evening, the next two in the string.

A team of staff and pupils at Taunton School in Somerset claimed to have picked up radio emissions from Jupiter from three of this week's impacts. Trevor Hill, head of physics at the independent school, said that all three followed a similar pattern - a burst of activity about an hour before impact (possibly caused as the fragment passed through the orbit of Jupiter's moon, Io), then a multiple burst on impact followed by two hours of constant emissions.

The amateur team picked up its strongest signals after Q1's impact. It is monitoring Jupiter at lower radio frequencies than professional observers, who use higher frequencies to receive more detailed information.

Micheal Garrett, an astronomer at Britain's Jodrell Bank radio observatory in Cheshire, said the Somerset findings appeared to correlate with those from the Beijing Astronomical Observatory in China monitoring at similar frequencies from Xinxiang.

By this morning, only two large chunks of the 3-million-mile-long comet train remained. These were due to hit Jupiter at about 5.15am and just after 9am. But the show does not quite stop then. For several weeks, astronomers expect small pieces of comet, from just a few centimetres to a few hundred metres across, to carry on raining into Jupiter.

Astronomers were yesterday trying to explain why they had not seen evidence of water vapour in Jupiter's atmosphere after Shoemaker-Levy 9 forced material from inner levels to the surface. It is possible that the comet chunks have not penetrated deep enough.

Robin Scagell, vice-president of the Society for Popular Astronomy, said amateur astronomers saw two big spots on Jupiter on Wednesday evening - the remains of impacts by fragments G and L: 'Like a huge pair of eyes looking out at us.'

(Photograph omitted)

Suggested Topics
Start your day with The Independent, sign up for daily news emails
Have you tried new the Independent Digital Edition apps?
ebooksA special investigation by Andy McSmith
Jerry Seinfeld Comedians in Cars Getting Coffee
peopleSitcom star urges men to be more supportive of women than ever
Life and Style
Living for the moment: Julianne Moore playing Alzheimer’s sufferer Alice
Jay Z
businessJay-Z's bid for Spotify rival could be blocked
footballLouis van Gaal is watching a different Manchester United and Wenger can still spring a surprise
The spider makes its break for freedom
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

Recruitment Genius: Sales Ledger Administrator

£14400 per annum: Recruitment Genius: This is an opportunity to join a multi-d...

Recruitment Genius: Service, Maintenance & Installation Engineers - London

£34000 - £36000 per annum: Recruitment Genius: This provider of Energy Consult...

Austen Lloyd: Planning Solicitor - Bristol

£50000 - £70000 per annum + Excellent Salary: Austen Lloyd: BRISTOL - FIRST CL...

Recruitment Genius: Production Planner - Night Shift

Negotiable: Recruitment Genius: A leading Leicestershire based chilled food ma...

Day In a Page

War with Isis: Iraq's government fights to win back Tikrit from militants - but then what?

Baghdad fights to win back Tikrit from Isis – but then what?

Patrick Cockburn reports from Kirkuk on a conflict which sectarianism has made intractable
Living with Alzheimer's: What is it really like to be diagnosed with early-onset dementia?

What is it like to live with Alzheimer's?

Depicting early-onset Alzheimer's, the film 'Still Alice' had a profound effect on Joy Watson, who lives with the illness. She tells Kate Hilpern how she's coped with the diagnosis
The Internet of Things: Meet the British salesman who gave real-world items a virtual life

Setting in motion the Internet of Things

British salesman Kevin Ashton gave real-world items a virtual life
Election 2015: Latest polling reveals Tories and Labour on course to win the same number of seats - with the SNP holding the balance of power

Election 2015: A dead heat between Mr Bean and Dick Dastardly!

Lord Ashcroft reveals latest polling – and which character voters associate with each leader
Audiences queue up for 'true stories told live' as cult competition The Moth goes global

Cult competition The Moth goes global

The non-profit 'slam storytelling' competition was founded in 1997 by the novelist George Dawes Green and has seen Malcolm Gladwell, Salman Rushdie and Molly Ringwald all take their turn at the mic
Pakistani women come out fighting: A hard-hitting play focuses on female Muslim boxers

Pakistani women come out fighting

Hard-hitting new play 'No Guts, No Heart, No Glory' focuses on female Muslim boxers
Leonora Carrington transcended her stolid background to become an avant garde star

Surreal deal: Leonora Carrington

The artist transcended her stolid background to become an avant garde star
LGBT History Month: Pupils discuss topics from Sappho to same-sex marriage

Education: LGBT History Month

Pupils have been discussing topics from Sappho to same-sex marriage
11 best gel eyeliners

Go bold this season: 11 best gel eyeliners

Use an ink pot eyeliner to go bold on the eyes with this season's feline flicked winged liner
Cricket World Cup 2015: Tournament runs riot to make the event more hit than miss...

Cricket World Cup runs riot to make the event more hit than miss...

The tournament has reached its halfway mark and scores of 300 and amazing catches abound. One thing never changes, though – everyone loves beating England
Katarina Johnson-Thompson: Heptathlete ready to jump at first major title

Katarina Johnson-Thompson: Ready to jump at first major title

After her 2014 was ruined by injury, 21-year-old Briton is leading pentathlete going into this week’s European Indoors. Now she intends to turn form into gold
Syrian conflict is the world's first 'climate change war', say scientists, but it won't be the last one

Climate change key in Syrian conflict

And it will trigger more war in future
How I outwitted the Gestapo

How I outwitted the Gestapo

My life as a Jew in wartime Berlin
The nation's favourite animal revealed

The nation's favourite animal revealed

Women like cuddly creatures whilst men like creepy-crawlies
Is this the way to get young people to vote?

Getting young people to vote

From #VOTESELFISH to Bite the Ballot