Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Jupiter: Friend or Foe?

24.08.2007
The traditional belief that Jupiter acts as a celestial shield, deflecting asteroids and comets away from the inner Solar System, has been challenged by the first in a series of studies evaluating the impact risk to the Earth posed by different groups of objects.

On Friday 24th August at the European Planetary Science Congress in Potsdam, Dr Jonathan Horner will present a study of the impact hazard posed to Earth by the Centaurs, the parent population of the Jupiter Family of comets (JFCs). The results show that the presence of a Jupiter-like planet in the Solar System does not necessarily lead to a lower impact rate at the Earth.


Dr Horner, from the UK’s Open University (OU), said, “The idea that a Jupiter-like planet plays an important role in lessening the impact risk on potentially habitable planets is a common belief but there has only really been one study done on this in the past, which looked at the hazard due to the Long Period Comets. We are carrying out an ongoing series of studies of the impact risks in planetary systems, starting off by looking at our own Solar System, since we know the most about it!”

The team at the OU developed a computer model that could track the paths of 100,000 Centaurs around the Solar System over 10 million years. The simulation was run five times: once with Jupiter at its current mass, once without a Jupiter, and then with planets of three-quarters, a half and a quarter the mass of Jupiter (for comparison, Saturn is about a third of the mass of Jupiter). The team found that the impact rate in a Solar System with a planet like our Jupiter is about comparable to the case where there is no Jupiter at all. However, when the mass of Jupiter was between these two extremes, the Earth suffered an increased number of impacts from the JFCs.

Dr Horner said, “We’ve found that if a planet about the mass of Saturn or a bit larger occupied Jupiter’s place, then the number of impacts on Earth would increase. However if nothing was there at all, there wouldn’t be any difference from our current impact rate. Rather than it being a clear cut case that Jupiter acts as a shield, it seems that Jupiter almost gives with one hand and takes away with the other!”

The study shows that if there is no giant planet present, the JFCs will not be diverted onto Earth-crossing orbits, so the impact rate at the Earth is low. A Saturn-mass planet would have the gravitational pull to inject objects onto Earth-crossing orbits, but would not be massive enough to easily eject objects from the Solar System. This means that there would be more objects on Earth-crossing orbits at any given time, and therefore more impacts. However, a planet with Jupiter’s vast mass can give objects the gravitational boost to eject them from the Solar System. Therefore, if Jupiter deflects JFCs to an Earth-crossing orbit, it may well later sweep them right out of the Solar System and off the collision course with the Earth.

The group is now assessing the impact risk posed to the Earth by the Asteroids and will go on to study the Long Period Comets, before examining the role of the position of Jupiter within our system.

Anita Heward | alfa
Further information:
http://www.europlanet-eu.org/index.php?option=com_content&task=view&id=102&Itemid=32

More articles from Physics and Astronomy:

nachricht Meteoritic stardust unlocks timing of supernova dust formation
19.01.2018 | Carnegie Institution for Science

nachricht Artificial agent designs quantum experiments
19.01.2018 | Universität Innsbruck

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: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>