After a decade-long journey chasing its target, ESA's
Comet 67P/Churyumov-Gerasimenko and
The comet is in an elliptical 6.5-year orbit that takes it from beyond Jupiter at its furthest point, to between the orbits of Mars and Earth at its closest to the Sun.
Comets are considered to be primitive building blocks of the Solar System and may have helped to 'seed' Earth with water, perhaps even the ingredients for life. But many fundamental questions about these enigmatic objects remain, and through a comprehensive,in situstudy of the comet,
The journey to the comet was not straightforward. Since its launch in 2004,
"After ten years, five months and four days travelling towards our destination, looping around the Sun five times and clocking up 6.4 billion kilometres, we are delighted to announce finally 'we are here'," says
Today saw the last of a series of ten rendezvous manoeuvres that began in May to adjust
"Today's achievement is a result of a huge international endeavour spanning several decades," says
"We have come an extraordinarily long way since the mission concept was first discussed in the late 1970s and approved in 1993, and now we are ready to open a treasure chest of scientific discovery that is destined to rewrite the textbooks on comets for even more decades to come."
The comet began to reveal its personality while
In the same period, first measurements from the Microwave Instrument for the Rosetta Orbiter, MIRO, suggested that the comet was emitting water vapour into space at about 300 millilitres per second.
Meanwhile, the Visible and Infrared Thermal Imaging Spectrometer, VIRTIS, measured the comet's average temperature to be about -70sC, indicating that the surface is predominantly dark and dusty rather than clean and icy.
Then, stunning images taken from a distance of about 12 000 km began to reveal that the nucleus comprises two distinct segments joined by a 'neck', giving it a duck-like appearance. Subsequent images showed more and more detail - the most recent, highest-resolution image was downloaded from the spacecraft earlier today and will be available this afternoon.
"Our first clear views of the comet have given us plenty to think about," says
"Is this double-lobed structure built from two separate comets that came together in the Solar System's history, or is it one comet that has eroded dramatically and asymmetrically over time?
At the same time, more of the suite of instruments will provide a detailed scientific study of the comet, scrutinising the surface for a target site for the Philae lander.
"Arriving at the comet is really only just the beginning of an even bigger adventure, with greater challenges still to come as we learn how to operate in this unchartered environment, start to orbit and, eventually, land," says Sylvain Lodiot, ESA's
As many as five possible landing sites will be identified by late August, before the primary site is identified in mid-September. The final timeline for the sequence of events for deploying Philae - currently expected for 11 November - will be confirmed by the middle of October.
"Over the next few months, in addition to characterising the comet nucleus and setting the bar for the rest of the mission, we will begin final preparations for another space history first: landing on a comet," says Matt.
CC AutoTriage14sp-140807-30FurigayJane-4821881 30FurigayJane
Most Popular Stories
- Cape Cod Building Mussel Industry
- Hollywood Eager to Grasp Hispanic Market
- Frightfully Fun Films Return for Halloween
- Would Soccer Be Richer Without Small Clubs?
- Cloud Lifts Microsoft's Quarterly Results
- Sears Denies Store Closings, Layoffs Report
- Weekly Jobless Claims Rise but Remain Low
- IS Funded by Black Market Oil Sales, Racketeering
- Pfizer Approves $11 Billion Buyback Plan
- Teresa Giudice Must Serve Time in Prison