Surface Chronology of Phobos – The Age of Phobos and its Largest Crater Stickney
Whereis Phobos 1? - ESO · Assembly in Baltimore (see photo). After the exhibitions in Malmö...
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Where is Phobos 1? The Soviet spacecraft Phobos 1, launched in July this year and now en route to Mars and its major moon, was lost due to an incorrect ground control command. Many attempts were made to reestablish radio-contact, but unfor- tunately in vain. On September 21, ESO received a request for observation of Phobos 1 from the Space Research Centre in Moscow. If it were possible to obtain a sequence of images of the spacecraft - of course only as a faint point of light - then its accurate position and perhaps even its rotational status could be deter- mined. This would help the efforts to re- acquire contact. At La Silla, the first possible night, September 22, was lost due to snow (see the "ND Picture Gallery" in this issue) and no observations of such a faint object could be made during the ensuing full moon period. However, ob- servations were carried out with the Oanish 1.5-m telescope on October 1/2, 2/3, and 3/4, resulting in at total of fif- teen 1O-minute exposures with the CCO camera. Moreover, ni ne 3-minute ex- posures were made with the EFOSC instrument at the 3.6-m telescope dur- ing the night October 3/4. The observers were visiting astronomers O. Hatzidimi- triou and C.A. Collins (Edingburgh); the image processing was made at La Silla by H.-U. N0rgaard-Nielsen (Copenha- gen) and H. Pedersen (ESO), who was also responsible for the coordination. We show here the central areas of two images from EFOSC. The one to the left is a direct exposure of the Phobos 1 field; the right one is a combined frame in which the 3.6-m telescope was set to follow the motion of the spacecraft; the stars are therefore seen as trails. The limiting magnitude in both cases is mag- nitude 25 or fainter. Since Phobos 1 is not seen, it must either have been out- side the field (did a rocket fire after the contact was lost?) or it was positioned so unluckily in space that the sunlight reflected from its surface in our direction was too faint to be detected, even with the present, extremely sensitive equip- ment. A final attempt was made with EFOSC on October 9/10, by visiting astronom- ers G. Suchail and Y. Mellier (Toulouse). Four frames, totalling 36 minutes V<{ere obtained, but again there was no sign of Phobos 1. It is a pity that this last-ditch effort was unsuccessful and that it was not possible to help our space colleagues this time. But it is a good example of the collaborative spirit that reigns in our field of science, and which transgresses all borders. The editor Open-Hause at ESO On October 22, 1988, the science in- stitutes in Garching again jointly or- ganized an open-house day. With the help of many of the staff members, a well-defined path was established through the ESO Headquarters with de- monstrations and exhibitions along the route. This year, around 1,800 persons vis- ited ESO. They were received at the entrance by the most "photogenic" staff members and guided towards the au- ditorium, where a new ESO slide show was running at 20-minute intervals. 12
Transcript of Whereis Phobos 1? - ESO · Assembly in Baltimore (see photo). After the exhibitions in Malmö...
Where is Phobos 1?
The Soviet spacecraft Phobos 1,launched in July this year and now enroute to Mars and its major moon, waslost due to an incorrect ground controlcommand. Many attempts were madeto reestablish radio-contact, but unfortunately in vain.
On September 21, ESO received arequest for observation of Phobos 1from the Space Research Centre inMoscow. If it were possible to obtain asequence of images of the spacecraft of course only as a faint point of light then its accurate position and perhapseven its rotational status could be determined. This would help the efforts to reacquire contact.
At La Silla, the first possible night,September 22, was lost due to snow(see the "ND Picture Gallery" in thisissue) and no observations of such afaint object could be made during theensuing full moon period. However, ob-
servations were carried out with theOanish 1.5-m telescope on October 1/2,2/3, and 3/4, resulting in at total of fifteen 1O-minute exposures with the CCOcamera. Moreover, nine 3-minute exposures were made with the EFOSCinstrument at the 3.6-m telescope during the night October 3/4. The observerswere visiting astronomers O. Hatzidimitriou and C.A. Collins (Edingburgh); theimage processing was made at La Sillaby H.-U. N0rgaard-Nielsen (Copenhagen) and H. Pedersen (ESO), who wasalso responsible for the coordination.
We show here the central areas of twoimages from EFOSC. The one to the leftis a direct exposure of the Phobos 1field; the right one is a combined framein which the 3.6-m telescope was set tofollow the motion of the spacecraft; thestars are therefore seen as trails. Thelimiting magnitude in both cases is magnitude 25 or fainter. Since Phobos 1 is
not seen, it must either have been outside the field (did a rocket fire after thecontact was lost?) or it was positionedso unluckily in space that the sunlightreflected from its surface in our directionwas too faint to be detected, even withthe present, extremely sensitive equipment.
A final attempt was made with EFOSCon October 9/10, by visiting astronomers G. Suchail and Y. Mellier (Toulouse).Four frames, totalling 36 minutes V<{ereobtained, but again there was no sign ofPhobos 1.
It is a pity that this last-ditch effortwas unsuccessful and that it was notpossible to help our space colleaguesthis time. But it is a good example of thecollaborative spirit that reigns in our fieldof science, and which transgresses allborders. The editor
Open-Hause at ESO
On October 22, 1988, the science institutes in Garching again jointly organized an open-house day. With thehelp of many of the staff members, awell-defined path was establishedthrough the ESO Headquarters with demonstrations and exhibitions along theroute.
This year, around 1,800 persons visited ESO. They were received at theentrance by the most "photogenic" staffmembers and guided towards the auditorium, where a new ESO slide showwas running at 20-minute intervals.
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Next, the ND and VLT projects wereexplained in the Council room; this included a full-scale model of an 8.2metre VLT mirror! (See the picture; thisroom was the only one at the Headquarters which was big enough.) In the terminal room, the advanced image processing systems caught the eyes of computer-minded persons of all ages and alsothe interesting demonstration by the STIECF of artificial intelligence. An overviewof the Hubble Space Telescope wasfollowed by a visit to the "Remote Control Room", from where two telescopesat La Silla are used for observations.
As usual, the names and orbits ofminor planets attracted much interestand an impressive demonstration of a
CCO camera ("seeing" in a completelydark room) convinced quite a few visitors about the witchcraft of modern astronomical technology.
Finally, there was a possibility to participate in the "ESO Astroquiz". Weilover 1,200 response sheets werecounted in the box at the end of the dayand when the prize-winners weredrawn, the first three were found tocome from places as far apart as München, Wolfratshausen and Regensburg.Each of them received a copy of theESO Book "Entdeckungen amSüdhimmel".
For them and many others, ESO was"worth the journey".
R.M. WEST
NOTE
ESO/NOAO WorkshopsIn the Messenger No. 52 and in
the Proceedings of the NOAO/ESOConference on "High ResolutionImaging" it was announced that thenext ESO/NOAO Workshop on experimental astrophysics with the title "Infrared Array Oetectors" wouldbe held in Tueson, Arizona, in theautumn of 1989.
We regret to inform you that thisWorkshop has been cancelled. Information on the next joint Workshop will be given in due time.
F. MERKLE, J. BECKERS
Upcoming ESO ExhibitionsAs reported in the last issue of the
Messenger, ESO organized a specialexhibition booth at the XXth lAU GeneralAssembly in Baltimore (see photo). Afterthe exhibitions in Malmö (Sweden)which is still running and another inInnsbruck (Austria) during NovemberOecember, the following are planned fornext year:The Hague, Netherlands, Museon,
opening on January 27;Münster, F. R. Germany, Museum für
Naturkunde, opening on April 20;Klagenfurt, Austria, Planetarium, open
ing end of June;Copenhagen, Oenmark, Tycho Brahe
Planetarium, opening in October;Stuttgart, F. R. Germany, Planetarium,
opening before Christmas.We hope that our local readers will
take the opportunity to visit theseevents.
Potentially interested organizers of future exhibitions are kindly requested to
contact the ESO Information Service(address on last page), since the planning for 1990 is about to start.
The exhibition has now been enlargedto include more information about thenewest scientific and technological developments. Of particular interest is thefull-scale model of a VLT mirror (53 m2)
and the fischertechnik VLT model of aunit telescope, described elsewhere inthis Messenger issue.
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