Mullard Space Science Laboratory

P R E S S  R E L E A S E
01 July 2005

Deep Impact mission - Surrey Scientists to supply NASA with images

NASA's Deep Impact mission is carrying a copper bullet the size of a coffee table which will collide with comet Tempel 1 (at 23,000 miles per hour!) on the morning of the 4th July 2005. The aim of the mission is to learn more about comets which are giant dirty icebergs and the leftover debris of the formation of the Sun and the planets 4,500 million years ago.

With Deep Impact we hope to learn more about the structure and composition of comets. These objects are thought to have remained untouched since their formation, containing pristine material and clues to conditions in the early Solar System.

The impact will either make a football stadium sized crater, break up the comet or go straight through the comet and out the other side!

Satellites and telescopes all around the world are observing this event and MSSL is leading the UK effort. NASA will use our data as we are taking such a wide range of observations.

Image of Comet 9P/Tempel 1 taken on 29 June 2005 using the Swift Ultraviolet/Optical Telescope (UVOT) through an ultraviolet filter centered on 2600 Angstroms. The image has been compensated for the motion of the comet on the sky, so background stars appear trailed.



All our images will be available from the MSSL website:


1. Isaac Newton Telescope in La Palma

Images taken by this telescope will allow the study of changes to the tail of comet Tempel 1. The impact should release material which will form bright condensations in the comet's tail. These condensations are then 'blown' down the tail due to the solar wind, giving us the speed of the solar wind. The comet is then acting as a solar wind probe, or a very large wind sock!

2.5 days later the Earth will be located in the same region of solar wind as the comet was and we can take another measurement of the wind speed.

INT gives us the broad picture of the impact event.

2. UK schmidt telescope

UK schmidt gives us a more detailed view with spectroscopic studies. We will be looking at how the amount of carbon monoxide ions and water ions change due to the impact. This will give information on what the comet is made of.

Overall, we will learn about composition of the comet and its structure and strength. Very important for the European Space Agency's Rosetta mission which will land on a comet.

3. Swift satellite

The observations planned with Swift will involve both the Ultra-Violet and Optical Telescope and the X-ray Telescope. The UVOT will look for changes in the Coma, while the XRT will search for changes in the X-ray emission caused by extra material being ejected and interacting with the Solar Wind. There may be an X-ray 'flash' as a result of the impact.

Also, the impact may result in a comet outburst. An outburst has never been observed before and if it happens in the Deep Impact event it will not only be the first one observed but will be observed across the spectrum.

See also the Deep Impact site:

Notes to Editors:

Mullard Space Science Laboratory, UCL

MSSL is situated in Holmbury St Mary between Dorking and Guildford, and is the Space and Climate Physics Department of University College London. The Group moved from London to Holmbury St Mary in 1965 after Holmbury House was purchased with funds donated by the Mullard electronics company. 150 scientists work at MSSL across 5 groups; solar and stellar physics, planetary and plasma physics, astrophysics, detector physics and climate physics. The laboratory houses world-class facilities to design, build and test instrumentation as well as analyse the data taken by the instruments in space.


Dr Lucie Green
Mullard Space Science Laboratory
Tel: 01483 204100 (Switchboard)