We reported earlier on the two-decade-old Earth Swingby Anomaly:

Since 1990, scientists and mission controllers at ESA and NASA have noticed that their spacecraft sometimes experience a strange variation in the amount of orbital energy they exchange with Earth during planetary swingbys. The unexplained variation is noticed as a tiny difference in speed gained or lost during the swingby when comparing that predicted by fundamental physics and that actually measured after the event.

Last week, after analysing the radiometric data gathered by ESA and NASA ground stations that tracked Rosetta during her successful 13 November swingby, ESA's Trevor Morley, the lead flight dynamics specialist on Rosetta, sent us a brief mail update. His report?

"For Rosetta's third and final Earth swingby, there was no anomaly."

(Access more details under 'Full story' below) -- Daniel

 Full story »

Today, NASA's popular "Astronomy Picture of the Day" website features a cool image acquired by none other than our favourite comet chaser, Rosetta! 

Our NASA colleagues wrote:

"Goodbye Earth. Earlier this month, ESA's interplanetary Rosetta spacecraft zoomed past the Earth on its way back across the Solar System. Pictured above, Earth showed a bright crescent phase featuring the South Pole to the passing rocket ship. Launched from Earth in 2004, Rosetta used the gravity of the Earth to help propel it out past Mars and toward a 2014 rendezvous with Comet Churyumov-Gerasimenko. Last year, the robot spacecraft passed asteroid 2867 Steins, and next year it is scheduled to pass enigmatic asteroid 21 Lutetia. If all goes well, Rosetta will release a probe that will land on the 15-km diameter comet in 2014."

On behalf of the entire team working on Rosetta, 'Thanks guys!' -- Daniel

(Click on the image above to view the original version in ESA website.)

Stubbe Hviid, OSIRIS Operations Manager, has sent us a response to a comment made on this post:

"In the last pic, I'm wondering what the tiny dots are (multiple white and one black) : due to Osiris?, to data processing?, to objects above clouds? (X,Y) for the black at (760pxl/2048, 456pxl/1083) and for one white at (753/2048, 172/1083). At least the block dot is also present on the first pic."

Stubbe says that the white dots are caused by cosmic ray events. When the images were taken, the spacecraft was in open space (of course). This means that the spacecraft experiences the full effect of the solar wind and high energy particles. These high energy particles are detected by the CCD as light flashes. On the surface of the Earth, we normally do not see these cosmic ray events because the atmosphere shields us.

The white dots due to the cosmic ray events are completely normal. For example, the coronagraph of ESA's SOHO satellite regularly experiences a bakeout. With respect to SOHO bakeout, Stubbe added:

It is the same effect but a different kind of detector. OSIRIS also has the capability to 'bake out' the CCD (also called annealing). As a rather extreme example of this, here's an image we took of Comet Machholz back in 2005, during which Rosetta was caught in a Coronal Mass Ejection solar flare with a radiation level about 100 000 times higher than normal.

Note a comment left by J.M. Mondelo, who observed Rosetta on 12 November 2009 (thanks for the link and great pictures!). -- Daniel

Kristin wrote to us early on Saturday morning, 14 November.

During the night of 13/14 November, the team at ESA's Optical Ground Station, Tenerife, imaged Rosetta receding from Earth. The spacecraft's brightness was very low as they were looking at the non-illuminated side of the solar arrays; in contrast, during approach, sunlight was reflected from the solar arrays toward us (this explains the long exposure time and bad image quality compared with the approach observations done on 11/12 and 12/13 November).

This movie was recorded between 04:51 and 05:20 UTC on 14 Nov. It consists of 10 images with an exposure time of  2 min and a separation of 3 min. The field is located in Leo and has a size of 5 x 5 arcmin; North is up and East is left. The telescope was tracking the stars so that Rosetta appears as a stripe while the stars appear as dots. Rosetta moves roughly from East to West. The bright star at the bottom of the image has magnitude 12.5, and the bright star at the top has magnitude 13.4.

This image was taken at 05:39 UTC on 14 Nov with an exposure time of 5 min. The field is located in Leo and has a size of 5 x 5 arcmin, North is up and East is left. The telescope was tracking the stars so that Rosetta appears as a stripe a little above centre-right of the image. The spacecraft moves less than 1 arcmin during the 5 min exposure, roughly from East to West. The brightest star at the bottom of the image has magnitude 12.6. Note that the vertical bright line that crosses Rosetta is a camera artefact. Kristin Wirth wrote:

"I will leave the Teide Observatory and Tenerife now, and head for the airport. I really enjoyed my time at the Optical Ground Station, together with a great team and at a special location - opposite the Teide mountain, with the clouds below us. I would like to thank everybody for their support, in particular Lilian Dominguez Palmero who operated the telescope for me." -- Kristin

And we're going to take this opportunity to thank Kristin for all her great help and input for the Rosetta Blog over the past week!

Finally, a 'farewell' (for now) from us both and a sincere 'thank you' to every one who visited the Rosetta Blog - it has been a lot of fun and we have especially enjoyed seeing the many comments left by visitors. 

We plan to be back again in 2010 as Rosetta continues on her fascinating journey to the outer Solar System - including preparations for deep-space hibernation and the encounter with asteroid Lutetia on 10 July 2010 (from a distance of just 3000 km!). --Amruta & Daniel

New images from the OSIRIS team received over the weekend! 

  

Click to download the hi-res version

False-colour composite of cloud structures in an anticyclone over the South Pacific. It depicts a portion of the scene below with five times the resolution. The image was taken with the narrow-angle camera on 13 November at 06:48 CET, using orange, green and blue optical filters

 

Click to download the hi-res version

Taken three minutes before the image above with the wide-angle camera, this image is shown in a logarithmic scale to bring out details in the varying light intensity. As a result the scene looks roughly the same as it would appear to the human eye.

Click to download the hi-res version

The same area in the South Pacific imaged with the orange filter of the narrow-angle camera in a logarithmic intensity scale.

--Amruta

As a reader commented, the images clearly show Earth smiling back at Rosetta!

The OSIRIS team has composed this animation from a sequence of images taken once every 24 hours, beginning when Rosetta was at a distance of 50 000 km at 22:28 UTC last night. The resolution is 6.5 km/pixel. Access the animation in the main ESA web site. -- Amruta

 

It's been a long day here on the Rosetta Blog - and we're finally getting some much-needed help from the Rosetta Flight Control Team's mascot, Orville - who, apparently, speaks French! :-) We'll log off for the the day now - thank you for visiting the Rosetta Blog -- Daniel

 

 

Rosetta's operations team just handed us a couple of breath-taking images taken by the spacecraft's navigation camera (navcam). The camera is actually designed for navigation purposes, so they aren't to be compared with the full-colour scientific capabilities of OSIRIS - but they are amazing views!

This image was captured at 14:23 UTC (15:23 CET), when Rosetta was at a distance of approximately 236 000 km from Earth's centre. It shows a cloud-covered North America in some detail. (Click on 'Full story' for a second cool pic!) -- Daniel

 Full story »

We're received a couple of emails from several colleagues around ESA and at the science teams working on Rosetta from other institutes. They've kindly sent in some of the data they've seen during the swingby campaign, and herewith we'd like to publish a couple of cool 'techie' updates.

The first came in from Anders Eriksson, the PI (principle investigator) for Rosetta's RPC-LAP at the Swedish Institute of Space Physics, Uppsala, and the second from ESA's Petteri Nieminen, working on Rosetta's SREM instrument at ESA/ESTEC, the Netherlands. Click on 'Full story' for details. -- Daniel

 Full story »

Just heard from the Flight Dynamics folks here at ESOC, and SOM Andrea Accomazzo dropped by with early news: It appears that Rosetta was just slightly more than 1.1 km from the planned swing-by target! This performance, if confirmed, means that her trajectory was more accurate than predicted. The perigee passage time (= time of closest approach) was less than 0.01 seconds different from the last prediction made before the swing-by. -- Daniel

Click on images to access full-size version. For detailed captions and information, access the ESA web portal.

 

Credits: ESA ©2009 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

 

Credits: ESA ©2009 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

 

 

 

 

Rather cool photos and video sent in by amateur radio astronomer Gérard Galve, who reports that he monitored Rosetta's signals from his backyard in Toulouse, France, this morning.

He was up and about at 02:00 with his friend, Bertrand, to catch ESA's comect chaser. They report picking up signals at 02:10... the video includes audio (the '...wheeeeeeee tone in the background') monitored at 08:01 UT (09:01 CET). Merci beaucoup, Messieurs! ... et "73!"

Access full album here: Reader submissions   

 

 

Marina, the wife of Rosetta Spacecraft Operations Manager (SOM) Andrea Accommzzo, sent him to work in the predawn darkness this morning with a wonderful "swingby quiche." It's decorated to show Rosetta at the point of closest approach, with the word 'Ciao!'. :-)

This isn't the first time she's gone out of her way to support the operations team. Thanks, Marina!

 

 

 

Armelle, member of the Rosetta operations team, just came in and told us that the Science data is being downloaded right now and it looks nominal!

--Amruta