|
Rosetta observes asteroid at close quarters
Imagewith
thanks to ESA and VAGA
ESA's comet chaser, Rosetta, on
Friday, 5 September 2008, flew by a small body in the main asteroid
belt, asteroid Steins, collecting a wealth of information about this
rare type of minor Solar System body.
At 20:58 CEST (18:58 UT) on Friday night, ESA's Rosetta probe
approached asteroid 2867 Steins, coming to within a distance of only
800 km from it. Steins is Rosetta's first nominal scientific
target in its 11 and half year mission to ultimately explore the
nucleus of Comet 67P/Churyumov-Gerasimenko.
The success of this 'close' encounter was confirmed at
22:14 CEST, when ESA's ground control team at the European Space
Operations Centre (ESOC) in Darmstadt, Germany, received initial
telemetry from the spacecraft. During the flyby operations,
Rosetta was out of reach as regards communication links because its
antenna had to be turned away from Earth. At a distance of
about 2.41 AU (360 million kilometres) from our planet, the radio
signal from the probe took 20 minutes to reach the ground.
Steins is a small asteroid of irregular shape with a diameter of
only 4.6 km. It belongs to the rare class of E-type asteroids,
which had not been directly observed by an interplanetary spacecraft
before. Such asteroids are quite small in size and orbit and
are mostly found in the inner part of the main asteroid belt located
between Mars and Jupiter. They probably originate from the
mantle of larger asteroids destroyed in the early history of the
Solar System, and are thought to be composed mainly of silicate
minerals with little or no iron content.
The data, collected by Rosetta on Friday, will now be analysed over
the coming days and weeks and will finally unveil the true nature of
Steins.
Through the study of minor bodies such as asteroids, Rosetta is
opening up a new window onto the early history of our Solar System.
It will give us a better understanding of the origins and evolution
of the planets,and also a key to better interpreting asteroid data
collected from the ground.
This is not Rosetta's first look at Steins. Over two years
ago, in March 2006, the Osiris camera onboard Rosetta observed the
brightness variations of this rotating asteroid from a distance of
159 million kilometres (a little over the distance between Earth and
the Sun), and was able to determine that the tiny asteroid spins
around its axis in about six hours.
Together with the two navigation cameras onboard, Osiris was again
pointed towards Steins on 4 August 2008 and continued to observe the
asteroid until 4 September 2008, in order to assist Rosetta's
navigation by optical means it is a first in the history of ESA
spacecraft operations. A few days before the flyby, most of
the Rosetta orbiter instruments, as well as the Philae lander
magnetometer, were switched on to collect science data on the
asteroid, with ever-increasing accuracy as the spacecraft closed in
on it.
Rosetta's powerful instruments have initially been focusing on the
asteroid's orbital motion, rotation, shape and density. As the
distance has diminished, the investigation has broadened to take in
the observation of surface properties and features, and the analysis
of the chemical and mineralogical composition of the terrain’s, as
well as their relative ages and the effects of the solar wind on the
surface.
At its closest approach, Rosetta flew by Steins at a relative speed
of 8.6 km/s. To keep the small asteroid in the field of view
of its instruments, the spacecraft had to perform a rapid and highly
demanding rotation manoeuvre, which had been successfully rehearsed
in March this year (2008).
A preliminary analysis of the first data from the flyby was
presented to the press at ESOC at 12:00 CEST 6 September 2008.
"Steins might be small, but we're making big science here. The
better we learn to know the different kinds of asteroids, the better
we will understand our origins in the past. Moreover, when
such Solar System wanderers escape from the belt they could become a
threat to Earth.
The better we know them, the
better we will be able to mitigate the risks some of them might
present in the future. Rosetta performed very well all along.
This was a complex manoeuvre to
keep such a small target in sight, but the spacecraft came through
with flying colours.
Now we are even more confident in
its capacity to conduct the complex tasks that await it at comet
Churyumov-Gerasimenko." said Dr David Southwood, ESA's
Director of Science and Robotic Exploration.
Science observations of Steins will continue until Wednesday, 10
September 2008.
Since its launch by an Ariane 5 rocket on 2 March 2004, Rosetta has
already travelled about 3.7 thousand million kilometres and swung by
the Earth twice and Mars once for gravity-assist manoeuvres.
On 17 December 2007, Rosetta will reach
the maximum distance from the Sun in its current orbit, and will
then head back towards Earth for the next and last gravitational
kick from our planet on 13 November 2009. This will give the
probe its final push toward its commentary target.
On its way, Rosetta is scheduled to conduct another flyby, this time
with the much larger (21) Lutetia asteroid, on 10 July 2010.
Arrival at 67P/Churyumov-Gerasimenko is
due by mid-2014. By that time the probe will have covered a
distance of about 6.5 thousand million kilometres.
Related stories on Southport & Mersey Reporter:-
Rosetta spacecraft meets asteroid Steins
= Click
here to read.
Exclusive:- Space Missions Has A Local
Connection = Click
here to read. |
PAWS FOR THOUGHT
DOG lovers in
Sefton are being warned of a scam which could lead them being duped
into paying hundreds of pounds for puppies that do not exist.
Trading Standards in the borough have been alerted to the scam after
a woman from Crosby nearly fell foul of buying a puppy online..
Conmen often from overseas, place online adverts for pedigree
puppies for 'adoption' claiming to be based in the UK.
They request the
funds to be sent by money transfer then upon receipt claim they will
arrange to have the puppy flown and delivered to your door.
Once the consumer sends the payment they then request a further fee
of £250 for insurance, inoculation fees etc which needs to be paid
before delivery can be confirmed. Consumers end up parting
with their cash to find that no puppy is going to be delivered.
The woman from Crosby didn't part with any cash and Trading
Standards is warning other residents in the borough to ignore such
scams and choose reputable breeders.
Sefton Council Trading Standards Manager, Andrew Naisbitt, said:-
"Please don't get sucked into a scam like this.What might seem
like a bargain to buy an adorable puppy is in fact another means by
scamsters to get their hands on your hard earned money. If you
are thinking of purchasing a dog, always choose a reputable breeder.
There are clubs and schemes available where you can get details of
accredited breeders."
For help and advice on all consumer issues, residents can contact
Consumer Direct on 08454 04 05 06.
Advise for residents:-
* Never buy a puppy on impulse, always make sure you view the puppy
before you purchase.
* Choose a reputable breeder, visit the Kennel Club or other
organisations for details of your nearest local breeder.
* Ask for a copy of the pup's pedigree and certificates of hip
scoring and eye testing.
* However cute the puppy looks don't always buy the first one you
see, go and look at a number of litters.
* Visit the breeder or the kennels and ask to see the mother and
pups together. A reputable breeder or kennel will expect you
to request this.
* If possible speak to people who have purchased dogs from the
breeder and find out about their temperament.
* If you are considering purchasing a pet, remember there are lots
of unwanted animals in rescue homes and shelters that are in need of
a loving home.
STOP, CHAIN, CHECK
ON the 16
August 2008 a man with a black labrador dog knocked at a premises in
the Marshside area of the town.
The man claimed to be blind and was invited in to the premises.
He asked the resident about his eye sight and asked him if he had
any impairments. Using a pen, the visitor wrote down the
answers to his question on a piece of paper. The man then left
the premises causing no alarm or distress.
Approximately 3 days later following a knock on his front door, the
resident, looked out from his upstairs window and noticed two men at
his front door wearing white shirts or tops and black bottoms.
He did not open the door but noticed when they failed to get a reply
they tried to gain access around the side/rear of the property.
They failed to gain entry.
The two incidents may or may not be connected. This message is
to advise members to report to the police if they have received any
similar or unusual visits that have left them feeling uneasy.
Home Watch advise is:-
Please remember to use the chain when you open the front door to a
stranger.
Ensure your rear door is kept locked.
What ever the story you are told by a stranger who cold calls at
your door, be very wary about letting them in to your property.
While your door is closed or you have the chain on, you are in
charge.
ISLE OF MAN STEAM PACKET COMPANY SUPPORTS WORLD FIREFIGHTER GAMES
THE Isle of
Man Steam Packet Company is pleased to have been able to support
local firefighters at the 10th World Firefighter Games.
The Company provided travel for 30 Island firefighters to and from
the event and would like to congratulate everyone who represented
the Isle of Man during the ten days of competition. Based in
an around Liverpool, the Games saw 3,500 firefighters representing
38 nations take part in 73 sports. There were 16 medals won by the
Isle of Man team – eight gold, five silver and three bronze.
The gold medal successes included Floyd Askin in light heavyweight
judo and Neil Parsons, who was awarded seven in trap, skeet and
sporting shooting. Sub-officer Mark Caley, who came 14th in
the mountain biking, said everyone involved had thoroughly enjoyed
the experience. “It was a fantastic event, and it was great to
meet up with so many colleagues from around the world. The mountain
biking was tough. It was a good course and great fun, but it did get
very muddy!” Chief Fire Officer Brian Draper, who came
23rd in the mountain biking, said:- “The Games take place
every two years and with this year’s event being held so close to
home, we really wanted to represent the Isle of Man. On behalf of
our team, I’d like to thank the Isle of Man Steam Packet Company for
providing travel for us to the games.” Other
competitors who took part included Tim Calladine, Gary Hinds and
Steve Brearley. Isle of Man Steam Packet Company Chief
Executive Mark Woodward said:- “We were only too pleased to be
able to help the Isle of Man Fire Service. The event is a fantastic
idea and we were happy to play our part in helping the team promote
the Island.” |
