5. השביטים נמצאים בשני אזורים עיקריים:
עננת אורט: לא ניתן לצפות בה ישירות בגלל המרחק ) 100 -50 אלף
יחידות אסטרונומיות( וגם בגלל שהשביטים אינם מאירים באזור זה.
משערים כי מקור השביטים באזור זה הוא מכוכבי הלכת הגדולים של
מערכת השמש.
שביטים עוזבים את העננה כתוצאה מהשפעת כוח כבידה של כוכבים
החולפים באזור. הערכה היא שכל שנה נכנסים כ 10 - שביטים לתוך
מערכת השמש. שביטים אלו הם בעלי זמן מחזור ארוך.
חגורת קויפר: שביטים בעלי מחזור קצר ) קטן מ 200 - שנה ( מגיעים
מחגורת קויפר הממוקמת במרחק של 60 -30 יחידות אסטרונומיות
15. This photo shows Rosetta being tested before it was wrapped in
insulating blankets and loaded on a rocket for launch.
16. Rosetta has massive solar wings to power the
spacecraft. They were unfurled and checked out at the
European Space Agency's test facilities before being
packed up for liftoff.
17.
18. Rosetta's mission started on March 2, 2004,
when it was launched on a European Ariane 5
rocket from Kourou, French Guiana.
19.
20.
21.
22. Deep space manoeuvres
• To achieve the required velocity to rendezvous with
67P/C-G, Rosetta used gravity assist manoeuvres to
accelerate throughout the Inner solar system
26. November 2007
After its closest approach to Earth Rosetta
captured this image of the planet.
27.
28. Rosetta passed asteroid 2867 Šteins in, giving scientists
amazing close-ups of the asteroid's huge crater. The
asteroid is about 3 miles in diameter.
September 2008
29. November 2009
Rosetta snapped this image of Earth in November 2009.
The spacecraft was 393,328 miles from Earth.
30. Beautiful Lutetia
10 July 2010
• Flew by and photographed the asteroid 21
Lutetia.
33. Go to sleep Rosetta!
8 June 2011
• The spacecraft was transferred into a spin
stabilised mode and all electronics except the
on-board computer and the hibernation
heaters were switched off
35. Wake-Up Rosetta!
20 January 2014
• At 10:00 UTC the spacecraft computer was
taken out of hibernation mode and started
post-hibernation procedures.
• Rosetta restored communications with ESOC
through NASA's Goldstone ground station at
18:18 UTC
49. 3 August 2014
Comet 67P/Churyumov-Gerasimenko by Rosetta’s OSIRIS narrow-angle camera on 3 August from
a distance of 285 km. The image resolution is 5.3 metres/pixel.
50.
51.
52. Arrive to the Comet!
7 minutes of maneuver.
6 August 2014
53.
54. Comet 67P/Churyumov-Gerasimenko by Rosetta’s OSIRIS narrow-angle camera on 3 August from
a distance of 285 km. The image resolution is 5.3 metres/pixel.
55. Stunning close up detail focusing on a smooth region on the ‘base’ of the ‘body’ section of
comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle
camera and downloaded today, 6 August. The image clearly shows a range of features, including
boulders, craters and steep cliffs.
The image was taken from a distance of 130 km and the image resolution is 2.4 metres per
pixel.
60. In Orbit around 67P/C-G!
• In August 2014, Rosetta rendezvoused with the comet,
commencing an approach to it on a triangular path
whose segments are hyperbolic escape trajectories,
alternating with thruster burns.
• After closing to within about 30 km (19 mi) from the
comet the spacecraft will enter actual orbit about
it,[7][8] in preparation for releasing a lander that will
make contact with the comet itself.
• The exact surface layout of the comet is currently
unknown and the orbiter has been built to map this
before detaching the lander. It is anticipated that a
suitable landing site can be found, although few
specific details exist regarding the surface
62. 20 August 2014
Rosetta navigation camera image taken on 20
August 2014 at about 83 km from comet
67P/Churyumov-Gerasimenko. The comet
nucleus is about 4 km across.
80. Time at spacecraft Time on Earth
Event Time (rel) Time (SCET, UT) Time (CET) Time (UT) Time (PT)
Rosetta Google Hangout -- -- Nov 7 16:00 Nov 7 15:00 Nov 7 07:00
ESOC media update (ESA TV) -- -- Nov 10 15:00 Nov 10 14:00 Nov 10 06:00
ESOC media update (ESA TV) -- -- Nov 11 11:00 Nov 11 10:00 Nov 11 02:00
24-hour ESA #CometLanding Livestream begins -- -- Nov 11 20:00 Nov 11 19:00 Nov 11 11:00
Go/no-go decision 1: proceed to downlink landing instructions to
Philae
-- -- Nov 11 20:35 Nov 11 19:35 Nov 11 11:35
ESOC media update (ESA TV) -- -- Nov 11 20:30 Nov 11 19:30 Nov 11 11:30
Go/no-go decision 2: ready for separation -- -- Nov 11 01:00 Nov 11 00:00 Nov 10 16:00
Go/no-go decision 3: proceed for delivery maneuver -- -- Nov 12 02:35 Nov 12 01:35 Nov 11 17:35
Rosetta pre-delivery maneuver (lining up for separation) -2h Nov 12 06:35 Nov 12 08:03 Nov 12 07:03 Nov 11 23:03
ESOC media update (ESA TV) -- -- Nov 12 07:15 Nov 12 06:15 Nov 11 22:15
Go/no-go decision 4: proceed for landing -- -- Nov 12 08:35 Nov 12 07:35 Nov 11 23:35
Lander separation (22.5 km from comet); Separation, Descent,
and Landing phase begins
+0h Nov 12 08:35 Nov 12 10:03 Nov 12 09:03 Nov 12 01:03
Rosetta divert maneuver +40m Nov 12 09:15 Nov 12 10:43 Nov 12 09:43 Nov 12 01:43
ESOC receives CIVA "farewell" image -- -- Nov 12 11:00 Nov 12 10:00 Nov 12 02:00
Rosetta point to Philae +2h Nov 12 10:35 Nov 12 12:03 Nov 12 11:03 Nov 12 03:03
Possible release of NavCam and/or CIVA "farewell" images -- -- Nov 12 13:00 Nov 12 12:00 Nov 12 04:00
Landing (time approx) +7h Nov 12 15:35 Nov 12 17:03 Nov 12 16:03 Nov 12 08:03
ESOC receives CIVA panorama -- -- Nov 12 17:35 Nov 12 16:35 Nov 12 08:35
Possible presentation of first images -- -- Nov 12 18:00 Nov 12 17:00 Nov 12 09:00
First science sequence begins Landing +1h Nov 12 16:35 Nov 12 18:03 Nov 12 17:03 Nov 12 09:03
24-hour ESA #CometLanding Livestream ends -- -- Nov 12 19:00 Nov 12 18:00 Nov 12 10:00
ESOC media update (ESA TV) -- -- Nov 13 14:00 Nov 13 13:00 Nov 13 05:00
First science sequence ends Landing +65h Nov 15 08:35 Nov 15 10:03 Nov 15 09:03 Nov 15 01:03
83. Philae lander
November 2014
• The lander, named Philae, will approach Churyumov–
Gerasimenko at relative speed around 1 m/s (2.2 mph;
3.6 km/h) and on contact with the surface,
two harpoons will be fired into the comet to prevent the
lander from bouncing off.
• Additional drills are used to further secure the lander on
the comet.
• After its attachment to the comet, expected to take place in
November 2014, the lander will begin its science mission:
– Characterisation of the nucleus
– Determination of the chemical compounds present,
including enantiomers[34]
– Study of comet activities and developments over time