A cosmic collision: Two satellites due to smash into surface of the moon… but don't worry, it was all planned by Nasa

NASA has deliberately guided the twin satellites into a cliff close to the moon’s northern pole

Two Nasa satellites will slam into the surface of the moon later today as they finish their 15-month lunar gravity measuring mission.

Nasa has deliberately guided the twin satellites, nicknamed Ebb and Flow, into a cliff close to the moon’s northern pole. The crash site has been chosen to avoid areas of historical significance, such previous moon landing locations.

Despite an estimated impact speed of 3,760mph, the impact is unlikely to be visible from earth, as the satellites are only about the size of a home washing machine and are carrying little or no fuel.

The crash marks the conclusion of the highly successful $496 million Grail mission, which launched in September 2011 to map the moon’s gravity field in unprecedented detail.

Maria Zuber, Grail’s principal investigator, told reporters: “Grail has produced the highest-resolution, highest-quality gravity field for any planet in the solar system, including Earth.”

According to Space.com, the resulting map revealed a pulverised lunar crust which suggests that the moon, Earth, Mars, Mercury and Venus have been pounded by impacts far more violently than previously thought.

With the two satellites running out of fuel, a collision with the moon’s surface was inevitable, so scientists opted for a controlled impact into an insignificant area.

On Friday morning the satellites’ control panels were switched off and scientists ordered the low-flying spacecraft to crash into the rim of a crater.

The impact is set to take place at 22.58 GMT, with the craft expected to create small holes in the moon surface but leave little other trace.

“They're going to be completely blown apart at the time,” said Grail mission manager David Lehman of Nasa's Jet Propulsion Laboratory in Pasadena, California.

Not content with the satellites’ successful gravitational mapping, scientists are hoping the impact itself will be something of a research mission.

There is hope that as the satellites slam into the moon’s surface, ice or other volatile material will be ejected into the atmosphere where it can be detected.

But the Grail team doesn't necessarily expect to see ice. The crater rim is in sunlight much of the time, and the craft aren't large enough to kick up much material.

News
Kenny Ireland, pictured in 2010.
peopleActor, from House of Cards and Benidorm, was 68
News
A scene from the video shows students mock rioting
newsEnd-of-year leaver's YouTube film features staging of a playground gun massacre
Travel
travel
Environment
View from the Llanberis Track to the mountain lake Llyn
Du’r Arddu
environmentA large chunk of Mount Snowdon, in north Wales, is up for sale
PROMOTED VIDEO
Voices
A family sit and enjoy a quiet train journey
voicesForcing us to overhear dull phone conversations is an offensive act, says Simon Kelner
News
i100This Instagram photo does not prove Russian army is in Ukraine
Arts and Entertainment
The cast of The Big Bang Theory in a still from the show
tvBig Bang Theory filming delayed by contract dispute over actors' pay
News
Morrissey pictured in 2013
people
Arts and Entertainment
The Secret Cinema performance of Back to the Future has been cancelled again
filmReview: Sometimes the immersive experience was so good it blurred the line between fiction and reality
Arts and Entertainment
Sydney and Melbourne are locked in a row over giant milk crates
art
Life and Style
The director of Wall-E Andrew Stanton with Angus MacLane's Lego model
gadgetsDesign made in Pixar animator’s spare time could get retail release
News
ebookA unique anthology of reporting and analysis of a crucial period of history
News
peopleGuitarist, who played with Aerosmith, Lou Reed and Alice Cooper among others, was 71
Environment
Tyred out: should fair weather cyclists have a separate slow lane?
environmentFormer Labour minister demands 'pootling lanes' for women cyclists
News
people
Sport
England celebrate a wicket for Moeen Ali
sportMoeen Ali stars with five wickets as Cook's men level India series
News
Field of broken dreams: Andy Bell visits Passchendaele
news5 News's Andy Bell visited the killing fields of the Great War, and his ancestor - known only from his compelling war diary - came to life
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

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

iJobs Job Widget
iJobs General

VB.Net Developer - £40k - Surrey - WANTED ASAP

£35000 - £40000 per annum + competitive: Progressive Recruitment: .Mid Level V...

Digitakl Business Analyst, Slough

£40000 - £45000 per annum + Competitive Benefits: Progressive Recruitment: Dig...

Mechanical Estimator: Nuclear Energy - Sellafield

£40000 - £50000 per annum + Car, Medical, Fuel + More!: Progressive Recruitmen...

Dynamics NAV Techno-Functional Consultant

£50000 - £60000 per annum + benefits: Progressive Recruitment: An absolutely o...

Day In a Page

Dress the Gaza situation up all you like, but the truth hurts

Robert Fisk on Gaza conflict

Dress the situation up all you like, but the truth hurts
Save the tiger: Tiger, tiger burning less brightly as numbers plummet

Tiger, tiger burning less brightly

When William Blake wrote his famous poem there were probably more than 100,000 tigers in the wild. These days they probably number around 3,200
5 News's Andy Bell retraces his grandfather's steps on the First World War battlefields

In my grandfather's footsteps

5 News's political editor Andy Bell only knows his grandfather from the compelling diary he kept during WWI. But when he returned to the killing fields where Edwin Vaughan suffered so much, his ancestor came to life
Lifestyle guru Martha Stewart reveals she has flying robot ... to take photos of her farm

Martha Stewart has flying robot

The lifestyle guru used the drone to get a bird's eye view her 153-acre farm in Bedford, New York
Former Labour minister Meg Hillier has demanded 'pootling lanes' for women cyclists

Do women cyclists need 'pootling lanes'?

Simon Usborne (who's more of a hurtler) explains why winning the space race is key to happy riding
A tale of two presidents: George W Bush downs his paintbrush to pen father’s life story

A tale of two presidents

George W Bush downs his paintbrush to pen father’s life story
Save the tiger: The day America’s love of backyard tigers led to a horrific bloodbath

The day America’s love of backyard tigers led to a horrific bloodbath

With only six per cent of the US population of these amazing big cats held in zoos, the Zanesville incident in 2011 was inevitable
Samuel Beckett's biographer reveals secrets of the writer's time as a French Resistance spy

How Samuel Beckett became a French Resistance spy

As this year's Samuel Beckett festival opens in Enniskillen, James Knowlson, recalls how the Irish writer risked his life for liberty and narrowly escaped capture by the Gestapo
We will remember them: relatives still honour those who fought in the Great War

We will remember them

Relatives still honour those who fought in the Great War
Star Wars Episode VII is being shot on film - and now Kodak is launching a last-ditch bid to keep celluloid alive

Kodak's last-ditch bid to keep celluloid alive

Director J J Abrams and a few digital refuseniks shoot movies on film. Simon Usborne wonders what the fuss is about
Once stilted and melodramatic, Hollywood is giving acting in video games a makeover

Acting in video games gets a makeover

David Crookes meets two of the genre's most popular voices
Could our smartphones soon be diagnosing diseases via Health Kit and Google Fit?

Could smartphones soon be diagnosing diseases?

Health Kit and Google Fit have been described as "the beginning of a health revolution"
Ryanair has turned on the 'charm offensive' but can we learn to love the cut-price carrier again?

Can we learn to love Ryanair again?

Four recent travellers give their verdicts on the carrier's improved customer service
Billionaire founder of Spanx launches range of jeans that offers

Spanx launches range of jeans

The jeans come in two styles, multiple cuts and three washes and will go on sale in the UK in October
10 best over-ear headphones

Aural pleasure: 10 best over-ear headphones

Listen to your favourite tracks with this selection, offering everything from lambskin earmuffs to stainless steel