Press Release

UK Infrared Telescope First to Detect Flare From Deep Impact

By SpaceRef Editor
July 7, 2005
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Astronomers at the United Kingdom Infrared Telescope in Hawaii were the first at a large research observatory to detect the success of NASA’s Deep Impact mission to comet Tempel 1, measuring the effects of the impact even before confirmation arrived from mission control at the Jet Propulsion Laboratory.

At 19:52:05 Hawaiian Standard Time on 3rd July, astronomers using the UK Infrared Telescope (UKIRT) saw a sudden and dramatic increase in the brightness of the comet. “We immediately realised that we were seeing the result of the impactor hitting the comet” said Dr. Paul Hirst, an astronomer at the Joint Astronomy Centre, which operates UKIRT.

UKIRT detected the flare with its ‘Fast Guide Camera’ – a visible-light camera that measured the comet’s brightness 20 times per second. The results were displayed instantly, so the team did not have to wait for the data to be processed.

Prof. Steve Miller of University College London explained: “UKIRT’s measurements were the first clear signal that impact had actually occurred. Major observatories around the world had joined a vast videoconference to share results, and Paul Hirst immediately told all the participants that UKIRT had detected the impact.”

Within about a minute, the comet flared to double its pre-impact brightness, and within an hour it was ten times brighter than before the impact. By measuring the rate at which the brightness increased, Prof. Miller estimated that the debris from the comet had been flung out at speeds of approximately 1100 kilometres per hour (700 miles per hour).

It was particularly exciting to detect the impact with the Fast Guide Camera, which was designed purely to improve measurements with UKIRT’s main scientific instruments by correcting for atmospheric turbulence. These results are an unexpected bonus in addition to Prof. Miller’s main project, the measurement of hot water vapour produced by the impact.

Prof. Gary Davis, Director of the Joint Astronomy Centre, said “We believe comets are composed of the pristine raw material from which our Solar System formed. Studying them can tell us more about the formation of other planetary systems. The results from UKIRT are stunning.”


* Schematic showing the dramatic increase in brightness of comet Tempel 1 as detected by the United Kingdom Infrared Telescope (UKIRT) following the impact. Credit: Joint Astronomy Centre. Background photograph of UKIRT by Nik Szymanek. (PNG image, 1.9MB)

* Plain version of above schematic: Schematic showing the dramatic increase in brightness of comet Tempel 1 as detected by the United Kingdom Infrared Telescope (UKIRT) following the impact. Credit: Joint Astronomy Centre. (PNG image, 59kB)

* From the United Kingdom Infrared Telescope (UKIRT) control room, astronomers study Deep Impact and the comet Tempel 1. Foreground (left to right): Steve Miller, Tom Stallard, Bob Barber. Background: Tim Carroll. Photo credit: Paul Hirst, Joint Astronomy Centre. (JPG image, 2.7MB)

* The United Kingdom Infrared Telescope (UKIRT) on the summit of Mauna Kea. Credit: Andy Adamson, Joint Astronomy Centre. (JPG image, 1.5MB)



The world’s largest telescope dedicated solely to infrared astronomy, the 3.8-metre (12.5-foot) UK Infrared Telescope (UKIRT) is sited near the summit of Mauna Kea, Hawaii, at an altitude of 4194 metres (13760 feet) above sea level. It is operated by the Joint Astronomy Centre in Hilo, Hawaii, on behalf of the UK Particle Physics and Astronomy Research Council (PPARC).


The Particle Physics and Astronomy Research Council (PPARC) is the UK’s strategic science investment agency. It funds research, education and public understanding in four broad areas of science – particle physics, astronomy, cosmology and space science. PPARC is government funded and provides research grants and studentships to scientists in British universities, gives researchers access to world-class facilities and funds the UK membership of international bodies such as the European Organisation for Nuclear Research, CERN, the European Space Agency and the European Southern Observatory. It also contributes money for the UK telescopes overseas on La Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology Centre at the Royal Observatory, Edinburgh and the MERLIN/VLBI National Facility.


Dr. Paul Hirst, UKIRT Support Astronomer
Joint Astronomy Centre, Hawaii
Tel: +1 808 969 6537

Prof. Steve Miller
University College London
Tel: +1 808 935 1460 (until 9th July)

Dr. Andy Adamson, UKIRT Head of Operations
Joint Astronomy Centre, Hawaii
Tel: +1 808 969 6511

Dr. Douglas Pierce-Price, Science Outreach Specialist
Joint Astronomy Centre, Hawaii
Tel: +1 808 969 6524


Joint Astronomy Centre

Joint Astronomy Centre public outreach site

This press release

SpaceRef staff editor.