Deep Impact at ESO

... News Archive

July 7, 2005: Observations continue at the ESO La Silla Paranal Observatory and more data are accumulated. The latest image taken with FOR S2 is shown here, while hereunder it is compared with the image taken on the night following the impact (left). The fan that appeared after the impact continues its expansion, and it is getting more and more diluted; it is still barely visible on the right side of the comet. The underlying coma is more and more similar to the pre-impact coma. In particular, no new jet feature is visible. As the spec ialist analysing the space mission images have not yet published their results on the orientation of the rotation axis of the nucleus, astronomer s still don't know exactly the orientation of the crater on this image. Once that information will be available, they will be able to analyze the coma structure in detail.


July 6, 2005 - 13:00: VISIR on Melipal took remarkable spectra of the comet before and after impact. They are compared in the image sho wn here. (Click to enlarge).

Light of the Sun is heating the dust particles surrounding a cometary nucleus. Infrared observations measure the thermal radiation emitted by the dust grains and allows to probe their temperature. In addition they offer valuable clues to study the chemical composition and the physical state of the dust in a comet. These informations help us to understand how and where comets were formed in the protoplanetary cloud about 4.55 billion years ago. The figure shows two spectra of comet Tempel 1 obtained in the mid-infrared spectral region (8 - 13 micron) with VISIR at UT3. The blue spectrum was obtained 4 hours before the impact, the red one during the following night, 20 hours after the impact. A very preliminary analysis shows that the flux of the thermal radiation has increased by about 25% after the impact. Is the material excavated by the impact different from the material coming from the surface? Observers are now trying to answer this question with further observations, in particular in the infrared with VISIR.


July 6, 2005 - 13:00: New FORS2 image of Comet Tempel 1 after impact. The large fan structure that was visible yesturday (18h after the impact) is diffusing away. Nevertheless, it is still present and well visible a s a "sharper" edge on the right side than on the left. See below for previous FORS2 images.



July 5, 2005 - 08:00: VLT First Images of Comet Tempel 1 After Impact


On the night of July 4, 2005, all ESO telescopes continued their extensive observing campaign of Comet Tempel 1. But this time, they were able to see the effect of the impact on the comet. The astronomers were clearly not disappointed. More...

July 5, 2005 - 06:05: As you may have seen from the live webcast, astronomers at the La Silla Paranal Observatory are still observing the comet as of now, for a few minutes still. The night has been excellent both at La Silla and Paranal and the observations went very well, with all telescopes.

July 4, 2005 - 22:05: Belgian astronomers, part of Deep Impact at ESO campaign, observing with the UVES spectrograph attached to VLT Kueye n 8.2m telescope, found from pre-impact high-quality, high-resolution spectra, convincing evidence for the presence of water in Comet Tempel 1. More...

July 4, 2005 - 20:53: The observers of the DI Campaign at ESO La Silla Paranal Observatory are now preparing for an exciting night, to obs erve the comet after the impact. They will then be able to compare with the images they obtained for two nights before the impact. At La Silla, o bservers are now starting the observations - in daylight - with the TIMMI2 infrared camera, hoping to detect the matter ejected by the comet afte r the impact.

July 4, 2005 - 14:00: First images by the Optical Monitor of the ESA XMM-Newton satellite showing the comet after impact are available here. From these images, XMM-Newton has detected water on Tempel 1.

July 4, 2005 - 10:21 a.m.: Deep Impact flyby's went as predicted. The space probe left shield mode in perfect condition. The ground-based observations has started but astronomers at the La Silla Paranal Observatory have to wait for another 14 hours or so before they can observe the comet.

July 4, 2005 - 8:40 a.m.: NASA has just released the first image of the impact.

July 4, 2005 - 7:52 a.m.: Big success for Deep Impact! The impactor provided exciting live images of the comet and was duly hit as planned by Comet Tempel 1.



TIMMI2 images taken at the 3.6m telescope at La Silla. The image on the left was taken on July 2, 2005 in good weather conditions. The one on the right was obtained on July 3 with small cirrus. The images were taken through the 12.9 micron filter. The pixel scale is 0.2 arcsec. The comet shows up four fold - negative and positive - without further processing. Only the image in the upper left corner gives the real structu re. The coma can be detected out to about 3 arcsec.

July 4, 2005 - 6:35 a.m.: The AutoNavigation system on Deep Impact's impactor spacecraft has completed its first planned maneuver to steer the craft into the path of comet Tempel 1.

July 4, 2005 - 5:37 a.m.: Everything goes apparently well with Deep Impact. Impact foreseen in a little more than 2 hours now...

July 3, 2005: The observers at the La Silla Paranal Observatory have had their first night of observations using all ESO's telescopes. The purpose of these pre-impact observations is to acquire an unprecedented and complete set of data with in total eleven instruments. The observations cover the wavelength domain between 350 nm (ultraviolet side of the visible light) and 20 micrometer (thermal infrared). More...

July 3, 2005: The Deep Impact impactor has been correctly released at 8:07 am. Deep Impact mission controllers have confirmed the impactor's S-band antenna is talking to the flyby spacecraft. All impactor data including the expected remarka ble images of its final dive into the comet's nucleus will be transmitted to the flyby craft - which will then downlink them to Deep Space Network antennas that are listening 134 million kilometers away.

July 3, 2005: The observers at the La Silla Paranal Observatory have had their first night of observations using all ESO's telescopes. Images will come later this afternoon.

July 1, 2005: Getting Ready for Cosmic Hit. Three days before the NASA Deep Impact spacecraft will collide with Comet 9P/Tempel 1, most astronomers who will use all ESO telescopes at the La Silla Paranal Observatory in Chile, have now arrived at their respective duty station and are carefully putting the last hand to the preparation of their observations. More...

July 1, 2005: Looking for molecules! Observers using ESO telescopes will not only make nice and detailed images of Comet 9P/Tempel 1 before and after the impact. They also perform complete spectroscopic analyses, to study the composition of the cometary ma terial, and in particular look for molecules. High-quality spectra have already been obtained that will serve as template for the post-impact obs ervations. See the details on the dedicated page.

June 29, 2005: Today, all European astronomers who will observe the effect of Deep Impact on Comet Tempel 1 with ESO's telescopes at La Si lla and Paranal meet in Santiago to look at the latest news about the comet and carefully define their strategy. They will leave tomorrow for the ir respective observatory. More details about the planned observations is available on the observation campaign page. You can also read interviews of Ulli Käufl, Olivier Hainaut and Hermann Boehnhardt, three of the astronomers participating to this ca mpaign. A video sequence of Ulli Käufl's interview is also available.

May 30, 2005: This web site opens. ESO Press Release 15/05 shows an image of Comet 9P/Tempel 1 taken with EMMI on the 3.5m NTT ESO telescopes.