News of the Comet-hunting Rosetta mission

[Carole]

Such a shame, but still a great success.  With a bit of luck it could wake up again as it approaches the Sun and gets more sunlight, or could even shift since it's not that stable.

Carole

[Carole]

Comet lander: Camera sees Philae's hairy landing
High-resolution pictures have now been released of the Philae probe in the act of landing on Comet 67P last Wednesday.

They were acquired by the Narrow Angle Camera on the Rosetta satellite, which had dropped the little robot towards the surface of the "ice mountain".

The images are presented as a mosaic covering the half-hour or so around the "first touchdown" - the probe then bounced to a stop about 1km away.

http://www.esa.int/spaceinimages/Images/2014/11/OSIRIS_spots_Philae_drifting_across_the_comet

http://www.bbc.co.uk/news/science-environment-30083969

[Rick]

Pioneering Philae Completes Main Mission Before Hibernation

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.

In addition, the lander's body was lifted by about 4 cm and rotated about 35° in an attempt to receive more solar energy. But as the last science data fed back to Earth, Philae's power rapidly depleted.

"It has been a huge success, the whole team is delighted," said Stephan Ulamec, lander manager at the DLR German Aerospace Agency, who monitored Philae's progress from ESA's Space Operations Centre in Darmstadt, Germany, this week.

"Despite the unplanned series of three touchdowns, all of our instruments could be operated and now it's time to see what we've got."

More from ESA

[Carole]

Some preliminary results, and more info from the Rosetta team:

http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-12176/year-all/#/gallery/17219

[Rick]

Did Philae drill the comet?

Philae's Sampling, Drilling and Distribution (SD2) subsystem was activated towards the end of the surface operations that Philae performed on Comet 67P/Churyumov-Gerasimenko last week, despite fears that it might alter the lander's precarious position following its third touchdown. Here we present the latest update from the SD2 team.

SD2's goal was to drill into the comet surface in order to collect and deliver samples to the COSAC and Ptolemy instruments inside the lander. It was the last of the lander's ten instruments to be operated.

SD2 principal investigator Amalia Finzi has reported that the drill was deployed as planned, extending 46.9 cm below the balcony of the lander and 56.0 cm from its reference point.

"It was then retracted to the reference position, the carousel turned in a way that the sampling tube was in front of the right oven, the discharge operation from the sampling tube to the oven was completed, and the carousel rotated in a way that that oven was positioned at COSAC's location," she said.

Although the ovens worked correctly, the scientists do not yet know how much – if any – material was actually delivered to the ovens by SD2, or whether the instruments sampled dust or gas that entered the chamber during the touchdown.

More: http://blogs.esa.int/rosetta/2014/11/19/did-philae-drill-the-comet/

[Rick]

Rosetta Continues Into Its Full Science Phase

With the Philae lander's mission complete, Rosetta will now continue its own extraordinary exploration, orbiting Comet 67P/Churymov–Gerasimenko during the coming year as the enigmatic body arcs ever closer to our Sun.

Last week, ESA's Rosetta spacecraft delivered its Philae lander to the surface of the comet for a dramatic touchdown.

The lander's planned mission ended after about 64 hours when its batteries ran out, but not before it delivered a full set of results that are now being analysed by scientists across Europe.

Rosetta's own mission is far from over and the spacecraft remains in excellent condition, with all of its systems and instruments performing as expected.

"With lander delivery complete, Rosetta will resume routine science observations and we will transition to the 'comet escort phase'," says Flight Director Andrea Accomazzo.

"This science-gathering phase will take us into next year as we go with the comet towards the Sun, passing perihelion, or closest approach, on 13 August, at 186 million kilometres from our star."

More from ESA

[Rick]

The Sound of Philae's Touchdown on Comet 67P/Churyumov-Gerasimenko

Sensors in the feet of Rosetta's lander Philae have recorded the sound of touchdown as it first came into contact with Comet 67P/Churyumov-Gerasimenko. The instrument, SESAME-CASSE, was turned on during the descent and clearly registered the first touchdown as Philae came into contact with the comet, in the form of vibrations detected in the soles of the lander's feet.

Hear it at: http://blogs.esa.int/rosetta/2014/11/20/the-sound-of-touchdown/

[Rick]

Rosetta Fuels Debate on Origin of Earth's Oceans

SA's Rosetta spacecraft has found the water vapour from its target comet to be significantly different to that found on Earth. The discovery fuels the debate on the origin of our planet's oceans.

The measurements were made in the month following the spacecraft's arrival at Comet 67P/Churyumov–Gerasimenko on 6 August. It is one of the most anticipated early results of the mission, because the origin of Earth's water is still an open question.

One of the leading hypotheses on Earth's formation is that it was so hot when it formed 4.6 billion years ago that any original water content should have boiled off. But, today, two thirds of the surface is covered in water, so where did it come from?

In this scenario, it should have been delivered after our planet had cooled down, most likely from collisions with comets and asteroids. The relative contribution of each class of object to our planet's water supply is, however, still debated.

The key to determining where the water originated is in its 'flavour', in this case the proportion of deuterium – a form of hydrogen with an additional neutron – to normal hydrogen.

Read more...

[Fay]

Thats interesting Rick

[JohnP]

http://esamultimedia.esa.int/multimedia/publications/ESABulletin160/

The latest ESA Bulletin – free to read online – features a wonderful Rosetta photo gallery documenting the last few months at Comet 67P/C-

[RobertM]

Good find, lovely pics in there.

[Rick]

Rosetta Comet 'Pouring' More Water Into Space

There has been a significant increase in the amount of water "pouring" out of comet 67P/Churyumov-Gerasimenko, the comet on which the Rosetta mission's Philae lander touched down in November 2014.

The 2.5-mile-wide (4-kilometer) comet was releasing the earthly equivalent of 40 ounces (1.2 liters) of water into space every second at the end of August 2014. The observations were made by NASA's Microwave Instrument for Rosetta Orbiter (MIRO), aboard the European Space Agency's Rosetta spacecraft. Science results from the MIRO team were released today as part of a special Rosetta-related issue of the journal Science.

"In observations over a period of three months [June through August, 2014], the amount of water in vapor form that the comet was dumping into space grew about tenfold," said Sam Gulkis, principal investigator of the MIRO instrument at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of a paper appearing in the special issue. "To be up close and personal with a comet for an extended period of time has provided us with an unprecedented opportunity to see how comets transform from cold, icy bodies to active objects spewing out gas and dust as they get closer to the sun."

More: http://www.jpl.nasa.gov/news/news.php?feature=4456

[Rick]

Rosetta Swoops In For A Close Encounter

ESA's Rosetta probe is preparing to make a close encounter with its comet on 14 February, passing just 6 km from the surface.

Yesterday was Rosetta's last day at 26 km from Comet 67P/Churyumov–Gerasimenko, marking the end of the current orbiting period and the start of a new phase for the rest of this year.

Today, Rosetta is moving into a new path ahead of a very close encounter next week. First, it will move out to a distance of roughly 140 km from the comet by 7 February, before swooping in for the close encounter at 12:41 GMT (13:41 CET) on 14 February. The closest pass occurs over the comet's larger lobe, above the Imhotep region.

"The upcoming close flyby will allow unique scientific observations, providing us with high-resolution measurements of the surface over a range of wavelengths and giving us the opportunity to sample – taste or sniff – the very innermost parts of the comet's atmosphere," says Matt Taylor, ESA's Rosetta project scientist.

The flyby will take Rosetta over the most active regions of the comet, helping scientists to understand the connection between the source of the observed activity and the atmosphere, or coma.

More: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_swoops_in_for_a_close_encounter

[Rick]

Rosetta: Comet's wind mystery may be solved

Scientists from the Rosetta mission may have solved the puzzle of features on Comet 67P that look like they were produced by wind.

Dust appears to be getting blown along the surface - a surprise finding on an "airless" body like a comet.

But the features could instead be created when cometary particles surrounding the nucleus fall back down again, disturbing the surface.

More: http://www.bbc.co.uk/news/science-environment-31917305

[Rick]

Rosetta makes first detection of molecular nitrogen at a comet

ESA's Rosetta spacecraft has made the first measurement of molecular nitrogen at a comet, providing clues about the temperature environment in which Comet 67P/Churyumov-Gerasimenko formed.

Rosetta arrived last August, and has since been collecting extensive data on the comet and its environment with its suite of 11 science instruments.

The in situ detection of molecular nitrogen has long been sought at a comet. Nitrogen had only previously been detected bound up in other compounds, including hydrogen cyanide and ammonia, for example.

Its detection is particularly important since molecular nitrogen is thought to have been the most common type of nitrogen available when the Solar System was forming. In the colder outer regions, it likely provided the main source of nitrogen that was incorporated into the gas planets. It also dominates the dense atmosphere of Saturn's moon, Titan, and is present in the atmospheres and surface ices on Pluto and Neptune's moon Triton.

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