ESA Rosetta mission: Philae instruments detect Organic molecules

The ESA Rosetta Philae lander has detected organic molecules on the surface of its comet, scientists have confirmed.

Carbon-containing "organics" are the basis of life on Earth and may give clues to chemical ingredients delivered to our planet early in its history.

The compounds were picked up by the German-built COSAC instrument designed to "sniff" the comet's thin atmosphere.

Other analyses suggest the comet's surface is largely water-ice covered with a thin dust layer.

The European Space Agency (ESA) craft touched down on the Comet 67P on 12 November after a 10-year journey.

Dr Fred Goessmann, principal investigator on the Cosac instrument, which made the organics detection, confirmed the find to reporters, but he added that the team was still trying to interpret the results.

It has not been disclosed which molecules have been found, or how complex they are.

But the results are likely to provide insights into the possible role of comets in contributing some of the chemical building blocks to the primordial mix from which life evolved on the early Earth.

Preliminary results from the MUPUS instrument, which deployed a hammer to the comet after Philae's landing, suggest there is a layer of dust 10-20cm thick on the surface with very hard water-ice underneath.

The ice would be frozen solid at temperatures encountered in the outer Solar System, MUPUS data suggest this layer has a tensile strength similar to sandstone.

"It's within a very broad spectrum of ice models. It was harder than expected at that location, but it's still within bounds," said Prof Mark McCaughrean, senior science adviser to ESA, told reporters.

"People will be playing with [mathematical] models of pure water-ice mixed with certain amount of dust."

He explained: "You can't rule out rock, but if you look at the global story, we know the overall density of the comet is 0.4g/cubic cm. There's no way the thing's made of rock.

"It's more likely there's sintered ice at the surface with more porous material lower down that hasn't been exposed to the Sun in the same way."

After bouncing off the surface at least twice, Philae came to a stop in some sort of high-walled trap.

"The fact that we landed up against something may actually be in our favour. If we'd landed on the main surface, the dust layer may have been even thicker and it's possible we might not have gone down [to the ice]," said Prof McCaughrean.

Scientists had to race to perform as many key tests as they could before Philae's battery life ran out at the weekend.

On re-charge

A key objective was to drill a sample of "soil" and analyse it in COSAC's oven, but, disappointingly, the latest information suggest no soil was delivered to the instrument.

Prof McCaughrean explained: "We didn't necessarily see many organics in the signal. That could be because we didn't manage to pick up a sample, but what we know is that the drill went down to its full extent and came back up again."

"But there's no independent way to say: This is what the sample looks like before you put it in there."

Scientists are hopeful however that as Comet 67P/Churyumov-Gerasimenko approaches the Sun in coming months, Philae's solar panels will see sunlight again.

This might allow the batteries to re-charge, and enable the lander to perform science once more.

"There's a trade off - once it gets too hot, Philae will die as well. There is a sweet spot," said Prof McCaughrean.

He added: "Given the fact that there is a factor of six, seven, eight in solar illumination and the last action we took was to rotate the body of Philae around to get the bigger solar panel in, I think it's perfectly reasonable to think it may well happen.

"By being in the shadow of the cliff, it might even help us, that we might not get so hot, even at full solar illumination, but if you don't get so hot that you don't overheat, have you got enough solar power to charge the system."

The lander's Alpha Particle X-ray Spectrometer (APXS), designed to provide information on the elemental composition of the surface, seems to have partially seen a signal from its own lens cover - which could have dropped off at a strange angle because Philae was not lying flat.

ESA Rosetta Philae completes science mission before shutdown

Philae's first touchdown seen by Rosetta's NavCam

Rosetta’s lander has completed its primary science mission after nearly 57 hours on Comet 67P/Churyumov–Gerasimenko.

After being out of communication visibility with the lander since 09:58 GMT / 10:58 CET on Friday, Rosetta regained contact with Philae at 22:19 GMT /23:19 CET last night.

The signal was initially intermittent, but quickly stabilised and remained very good until 00:36 GMT / 01:36 CET this morning.

In that time, the lander returned all of its housekeeping data, as well as science data from the targeted instruments, including ROLIS, COSAC, Ptolemy, SD2 and CONSERT.

This completed the measurements planned for the final block of experiments on the surface.

ESA Rosetta Team select Landing Date for Philae

The ESA Rosetta team says it will attempt to land the first spacecraft on a comet on Nov. 12.

It says the maneuver will take about seven hours starting from the moment its unmanned probe Rosetta releases the 100-kilogram lander at 0835 GMT (0335 EST).

Because of the 28 minutes it takes the signal to travel back to Earth, confirmation of a successful landing won't arrive until about shortly after 1600 GMT (1100 EST).

ESA said in a statement Friday that it has a backup plan in case of a problem with the preferred landing site.

Scientists hope the decade-long mission to examine comet 67P/Churyumov-Gerasimenko will help them learn more about the origins and evolution of objects in the universe.

Site J was chosen unanimously over four other candidate sites as the primary landing site because the majority of terrain within a square kilometre area has slopes of less than 30º relative to the local vertical and because there are relatively few large boulders.

The area also receives sufficient daily illumination to recharge Philae and continue surface science operations beyond the initial 64-hour battery-powered phase.

ESA Rosetta: Comet chaser nears its target - Comet 67P/Churyumov-Gerasimenko

This artist's impression shows the Rosetta orbiter at comet 67P/Churyumov-Gerasimenko. The image is not to scale. 

Credit: ESA/ATG Medialab

After a decade-long quest spanning six billion kilometres (3.75 billion miles), the European probe Rosetta, will come face to face Wednesday with a comet, one of the Solar System's enigmatic wanderers.

The moment will mark a key phase of the most ambitious project ever undertaken by the European Space Agency (ESA), a 1.3 billion euro ($1.76 billion) bid to get to know these timeless space rovers.

More than 400 million km from where it was launched in March 2004, the spacecraft Rosetta will finally meet up with its prey, Comet 67P/Churyumov-Gerasimenko.

To get there, Rosetta has had to make four flybys of Mars and Earth, using their gravitational force as a slingshot to build up speed, and then entering a 31-month hibernation as light from the distant Sun became too weak for its solar panels.

It was awakened in January.

After braking manoeuvres, the three-tonne craft should on Wednesday be about 100 km from the comet—a navigational feat that, if all goes well, will be followed by glittering scientific rewards.

"It's taken more than 10 years to get here," said Sylvain Lodiot, spacecraft operations manager.

"Now we have to learn how to dock with the comet, and stay with it for the months ahead."

Halley's Comet (1P/Halleys)

Blazing across the sky as they loop around the Sun, comets have long been considered portents of wonderful or terrible events, the birth and death of kings, bountiful harvests or famines, floods or earthquakes.

Astrophysicists, though, see them rather differently.

Comets, they believe, are clusters of the oldest dust and ice in the Solar System, the rubble left from the formation of the planets 4.6 billion years ago.

These so-called dirty snowballs could be the key to understanding how the planets coalesced after the Sun flared into life, say some.

Indeed, one theory, the "pan-spermia" hypothesis, is that comets, by bombarding the fledgling Earth, helped kickstart life here by bringing water and organic molecules.

Until now, though, explorations of comets have been rare and mainly entailed flybys by probes on unrelated missions snatching pictures from thousands of kilometres away.

Exceptions were the US probe Stardust, which brought home dust snatched from a comet's wake, while Europe's Giotto ventured to within 200 km of a comet's surface.

On November 11, the plan is for Rosetta to inch to within a few kilometres of the comet to send down a 100-kilogramme (220-pound) refrigerator-sized robot laboratory, Philae.

ESA Rosetta's Lander, Philae

Anchored to the surface, Philae will carry out experiments in cometary chemistry and texture for up to six months.

After the lander expires, Rosetta will accompany Comet 67P (C-G) as it passes around the Sun and heads out towards the orbit of Jupiter.

Read the full story here

ESA Rosetta 67P/Churyumov-Gerasimenko: Comet 'sweats' two glasses of water per second

This artist's impression shows the Rosetta orbiter at comet 67P/Churyumov-Gerasimenko. The image is not to scale. 

Credit: ESA/ATG Medialab

Unprecedented measurement of a deep-space comet has found the icy body to be losing about two small glasses of water every second, the European Space Agency (ESA) said on Monday.

ESA's Rosetta, made the measurements on June 6, when it aimed a microwave sensor at 67P/Churyumov-Gerasimenko, on which it will land a probe in August after a 10-year space trek.

It found the comet lost 300 millilitres (10.5 fluid ounces) of water in vapour every second, even though it was still 583 million kilometres (364 million miles) from the Sun, which it orbits.

The measurement is a technical feat, carried out when Rosetta was still 350,000 km from the comet.

It also indicates that the Sun starts to have a visible impact on comets even when the wanderers are still at a great distance, ESA said in a press release.

"We always knew we would see water vapour outgassing from the comet, but we were surprised at how early we detected it," said Sam Gulkis of NASA's Jet Propulsion Laboratory, who is in charge of Rosetta's MIRO microwave instrument.

"At this rate, the comet would fill an Olympic-size swimming pool in about 100 days but, as it gets closer to the Sun, the... production rate will increase significantly."

Comets follow elliptical paths around the Sun, spewing spectacular tails of gas, dust and frozen water as heat from the hot star causes surface ice to evaporate.

These tails, illuminated in the Sun's rays, are what makes comets so spectacular when seen from Earth.

Launched in 2004, Rosetta is designed to team up with "67P" in August and follow it on its journey around the Sun.

In November, it will send down a 100-kilogramme (220-pound) refrigerator-sized lander, Philae, which will hook itself to the comet's surface and carry out scientific experiments.

On Monday, the spacecraft was within 72,000 km of its destination, ESA said.

Six manoeuvres will be needed over the coming weeks to ensure that it arrives at a distance of just 100 km from the rock on August 6.

The comet, with Rosetta as its escort, will be at its closest to the Sun in August 2015, when it will be between the orbits of Earth and Mars.

Comets are sometimes called "dirty snowballs"—but cosmologists say their primeval mix of ice and dust forms time capsules that offer insights into how the Solar System formed 4.5 billion years ago.

Some scientists believe comets may have brought much of the water in today's oceans and possibly complex molecules that kickstarted life on Earth.

ESA Rosetta Mission: Waking up from Hibernation

Philae landing on comet

Next year, on 20 January, after 957 days of hibernation in deep space, ESA’s comet-chasing Rosetta spacecraft is set to wake up automatically en route to the destination it has been travelling towards for nearly a decade.

In preparation for the critical activation and the challenges that lie ahead for Rosetta, members of the media are invited to a briefing by ESA’s science and mission control experts and partners on Tuesday, 10 December, 10:00–12:30 CET, at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany.

The 20 January milestone will mark the start of an intensive year as Rosetta draws steadily closer to comet Churyumov–Gerasimenko ahead of rendezvous in August.

After extensively mapping the comet’s surface, it will dispatch the lander Philae in November for close-up study of the nucleus.

Rosetta will then follow the comet on its journey through the inner Solar System, monitoring the ever-changing conditions as it warms up heading towards its closest approach to the Sun, in August 2015.

Rosetta’s main objective is to help understand the origin and evolution of the Solar System, in particular investigating the role that comets may have played in seeding Earth with water, and perhaps even life.