Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble provides spectacular view of ongoing comet breakup

28.04.2006


The NASA/ESA Hubble Space Telescope is providing astronomers with extraordinary views of comet 73P/Schwassmann-Wachmann 3 as it disintegrates before our eyes. Recent Hubble images have uncovered many more fragments than have been reported by ground-based observers. These observations provide an unprecedented opportunity to study the demise of a comet nucleus.


Hubble Space Telescope is providing astronomers with extraordinary views of Comet 73P/Schwassmann-Wachmann 3. The fragile comet is rapidly disintegrating as it approaches the Sun. Hubble images have uncovered many more fragments than have been reported by ground-based observers. These observations provide an unprecedented opportunity to study the demise of a comet nucleus. The comet is currently a chain of over 33 separate fragments, named alphabetically, stretching across the sky by several times the angular diameter of the Moon. Hubble caught fragment B during three days shortly after large outbursts in activity (from top to bottom: 18 April, 19 April and 20 April). Hubble shows several dozen "mini-comets” trailing behind each main fragment, probably associated with the ejection of house-sized chunks of surface material. Deep-freeze relics of the early Solar System, cometary nuclei are porous and fragile mixes of dust and ices that can break apart due to the thermal, gravitational, and dynamical stresses of approaching the Sun. Whether any of the many fragments survive the trip around the Sun remains to be seen in the weeks ahead. Credit: NASA, ESA, H. Weaver (APL/JHU), M. Mutchler and Z. Levay (STScI)



Amateur and professional astronomers around the world have been tracking the spectacular disintegration of 73P/Schwassmann-Wachmann 3 for years. As it plummets towards a close encounter with the Sun, swinging round the Sun on 7 June and heading away to begin another loop round the Solar System, the comet will pass the Earth on 12 May, at a distance of 11.7 million kilometres, or 30 times the distance between Earth and the Moon.

The comet currently comprises a chain of over 33 separate fragments, named alphabetically, and stretching across several degrees on the sky (the Sun and Moon each have an apparent diameter of about 1/2 a degree). Ground-based observers have noted dramatic brightening events associated with some of the fragments indicating that they are continuing to break up and that some may disappear altogether.


Hubble caught two of the fragments, B and G, shortly after major outbursts in activity. The resulting images reveal that an amazing process of hierarchical destruction is taking place, in which the larger fragments are continuing to break up into smaller chunks. Several dozen "mini-fragments" are to be found trailing behind each main fragment, probably associated with the ejection of house-sized chunks of surface material that can only be detected in these very high-resolution Hubble images.

Sequential Hubble images of the B fragment, taken a few days apart, suggest that the chunks are pushed down the tail by outgassing from the icy, sunward-facing surfaces of the chunks, much like space-walking astronauts are propelled by their jetpacks. The smaller chunks have the lowest mass, and so are accelerated away from the parent nucleus faster than the larger chunks. Some of the chunks seem to dissipate completely over the course of several days.

One of the European team members, Philippe Lamy from Laboratoire d’Astrophysique de Marseille, France, says “When we observed the comet in late 2001 we concluded that many small, by then invisible, fragments had to be created by fragmentation to account for the missing mass. The new Hubble observations beautifully confirm and illustrate our past findings.”

Cometary nuclei are deep-frozen relics of the early Solar System, consisting of porous and fragile mixes of dust and ices. They can be broken up by many different mechanisms: be ripped apart by gravitational tidal forces when they pass near large bodies (for example, Comet Shoemaker-Levy 9 was torn to pieces when it skirted near Jupiter in 1992, before plunging into Jupiter’s atmosphere a year later), fly apart as the nucleus rotates rapidly, crumble under thermal stresses as they pass near the Sun, or pop apart explosively like corks from champagne bottles as trapped volatile gases burst out.

"Catastrophic breakups may be the ultimate fate of most comets," says planetary astronomer Hal Weaver of the Johns Hopkins University Applied Physics Laboratory, who led the international team that made the recent Hubble observations and who used Hubble previously to study the fragmentations of comets Shoemaker-Levy 9 in 1993-1994, Hyakutake in 1996, and 1999 S4 (LINEAR) in 2000. Analysis of the new Hubble data, and data taken by other observatories as the comet approaches the Earth and Sun, may reveal which of these breakup mechanisms are contributing to the disintegration of 73P/Schwassmann-Wachmann 3.

German astronomers Arnold Schwassmann and Arno Arthur Wachmann discovered this comet during a photographic search for asteroids in 1930, when the comet passed within 9.3 million kilometres of the Earth (only 24 times the Earth-Moon distance). The comet orbits the Sun every 5.4 years, but it was not seen again until 1979. The comet was missed again in 1985 but has been observed at every return since then.

During the autumn of 1995, the comet had a huge outburst in activity and shortly afterwards four separate nuclei were identified and labelled "A", "B", "C", and "D", with "C" being the largest and the presumed principal remnant of the original nucleus. Only the C and B fragments were definitively observed during the next return, possibly because of the poor geometry of the 2000-2001 apparition. The much better observing circumstances during this year’s return may be partly responsible for the detection of so many new fragments, but it is also likely that the disintegration of the comet is now accelerating. Whether any of the many fragments will survive the trip around the Sun remains to be seen.

Lars Christensen | alfa
Further information:
http://www.spacetelescope.org/news/html/heic0605.html

More articles from Physics and Astronomy:

nachricht New record in materials research: 1 terapascals in a laboratory
22.07.2016 | Universität Bayreuth

nachricht Mapping electromagnetic waveforms
22.07.2016 | Max-Planck-Institut für Quantenoptik

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Mapping electromagnetic waveforms

Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.

Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...

Im Focus: Continental tug-of-war - until the rope snaps

Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases

Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...

Im Focus: A Peek into the “Birthing Room” of Ribosomes

Scaffolding and specialised workers help with the delivery – Heidelberg biochemists gain new insights into biogenesis

A type of scaffolding on which specialised workers ply their trade helps in the manufacturing process of the two subunits from which the ribosome – the protein...

Im Focus: New protocol enables analysis of metabolic products from fixed tissues

Scientists at the Helmholtz Zentrum München have developed a new mass spectrometry imaging method which, for the first time, makes it possible to analyze hundreds of metabolites in fixed tissue samples. Their findings, published in the journal Nature Protocols, explain the new access to metabolic information, which will offer previously unexploited potential for tissue-based research and molecular diagnostics.

In biomedical research, working with tissue samples is indispensable because it permits insights into the biological reality of patients, for example, in...

Im Focus: Computer Simulation Renders Transient Chemical Structures Visible

Chemists at the University of Basel have succeeded in using computer simulations to elucidate transient structures in proteins. In the journal Angewandte Chemie, the researchers set out how computer simulations of details at the atomic level can be used to understand proteins’ modes of action.

Using computational chemistry, it is possible to characterize the motion of individual atoms of a molecule. Today, the latest simulation techniques allow...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

GROWING IN CITIES - Interdisciplinary Perspectives on Urban Gardening

15.07.2016 | Event News

SIGGRAPH2016 Computer Graphics Interactive Techniques, 24-28 July, Anaheim, California

15.07.2016 | Event News

Partner countries of FAIR accelerator meet in Darmstadt and approve developments

11.07.2016 | Event News

 
Latest News

Hey robot, shimmy like a centipede

22.07.2016 | Information Technology

New record in materials research: 1 terapascals in a laboratory

22.07.2016 | Physics and Astronomy

University of Graz researchers challenge 140-year-old paradigm of lichen symbiosis

22.07.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>