Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Do missing Jupiters mean massive comet belts?

27.11.2012
Using ESA’s Herschel space observatory, astronomers have discovered vast comet belts surrounding two nearby planetary systems known to host only Earth-to-Neptune-mass worlds. The comet reservoirs could have delivered life-giving oceans to the innermost planets.
In a previous Herschel study, scientists found that the dusty belt surrounding nearby star Fomalhaut must be maintained by collisions between comets.

Debris disc around GJ 581


Debris disc around 61 Vir

In the new Herschel study, two more nearby planetary systems – GJ 581 and 61 Vir – have been found to host vast amounts of cometary debris.

Herschel detected the signatures of cold dust at 200ºC below freezing, in quantities that mean these systems must have at least 10 times more comets than in our own Solar System’s Kuiper Belt.

GJ 581, or Gliese 581, is a low-mass M dwarf star, the most common type of star in the Galaxy. Earlier studies have shown that it hosts at least four planets, including one that resides in the ‘Goldilocks Zone’ – the distance from the central sun where liquid surface water could exist.

Two planets are confirmed around G-type star 61 Vir, which is just a little less massive than our Sun.

The planets in both systems are known as ‘super-Earths’, covering a range of masses between 2 and 18 times that of Earth.

Interestingly, however, there is no evidence for giant Jupiter- or Saturn-mass planets in either system.

The gravitational interplay between Jupiter and Saturn in our own Solar System is thought to have been responsible for disrupting a once highly populated Kuiper Belt, sending a deluge of comets towards the inner planets in a cataclysmic event that lasted several million years.

“The new observations are giving us a clue: they’re saying that in the Solar System we have giant planets and a relatively sparse Kuiper Belt, but systems with only low-mass planets often have much denser Kuiper belts,” says Dr Mark Wyatt from the University of Cambridge, lead author of the paper focusing on the debris disc around 61 Vir.

“We think that may be because the absence of a Jupiter in the low-mass planet systems allows them to avoid a dramatic heavy bombardment event, and instead experience a gradual rain of comets over billions of years.”

“For an older star like GJ 581, which is at least two billion years old, enough time has elapsed for such a gradual rain of comets to deliver a sizable amount of water to the innermost planets, which is of particular importance for the planet residing in the star’s habitable zone,” adds Dr Jean-Francois Lestrade of the Observatoire de Paris who led the work on GJ 581.

However, in order to produce the vast amount of dust seen by Herschel, collisions between the comets are needed, which could be triggered by a Neptune-sized planet residing close to the disc.

“Simulations show us that the known close-in planets in each of these systems cannot do the job, but a similarly-sized planet located much further from the star – currently beyond the reach of current detection campaigns – would be able to stir the disc to make it dusty and observable,” says Dr Lestrade.

“Herschel is finding a correlation between the presence of massive debris discs and planetary systems with no Jupiter-class planets, which offers a clue to our understanding of how planetary systems form and evolve,” says Göran Pilbratt, ESA’s Herschel project scientist.

Markus Bauer | EurekAlert!
Further information:
http://www.esa.int
http://www.esa.int/SPECIALS/Herschel/SEMVDXDQZ9H_0.html

More articles from Physics and Astronomy:

nachricht Australian technology installed on world’s largest single-dish radio telescope
26.09.2016 | International Centre for Radio Astronomy Research (ICRAR)

nachricht How to merge two black holes in a simple way
26.09.2016 | Plataforma SINC

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: Quantenboost für künstliche Intelligenz

Intelligente Maschinen, die selbständig lernen, gelten als Zukunftstrend. Forscher der Universität Innsbruck und des Joint Quantum Institute in Maryland, USA, loten nun in der Fachzeitschrift Physical Review Letters aus, wie Quantentechnologien dabei helfen können, die Methoden des maschinellen Lernens weiter zu verbessern.

In selbstfahrenden Autos, IBM's Watson oder Google's AlphaGo sind Computerprogramme am Werk, die aus Erfahrungen lernen können. Solche Maschinen werden im Zuge...

Im Focus: Synthese-chemischer Meilenstein: Neues Ferrocenium-Molekül entdeckt

Wissenschaftler der Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) haben zusammen mit Kollegen der Freien Universität Berlin ein neues Molekül entdeckt: Die Eisenverbindung in der seltenen Oxidationsstufe +4 gehört zu den Ferrocenen und ist äußerst schwierig zu synthetisieren.

Metallocene werden umgangssprachlich auch als Sandwichverbindungen bezeichnet. Sie bestehen aus zwei organischen ringförmigen Verbindungen, den...

Im Focus: Neue Entwicklungen in der Asphären-Messtechnik

Kompetenzzentrum Ultrapräzise Oberflächenbearbeitung (CC UPOB) lädt zum Expertentreffen im März 2017 ein

Ob in Weltraumteleskopen, deren Optiken trotz großer Abmessungen nanometergenau gefertigt sein müssen, in Handykameras oder in Endoskopen − Asphären kommen in...

Im Focus: Mit OLED Mikrodisplays in Datenbrillen zur verbesserten Mensch-Maschine-Interaktion

Das Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP arbeitet seit Jahren an verschiedenen Entwicklungen zu OLED-Mikrodisplays, die auf organischen Halbleitern basieren. Durch die Integration einer Bildsensorfunktion direkt im Mikrodisplay, lässt sich u.a. die Augenbewegung in Datenbrillen aufnehmen und zur Steuerung von Display-Inhalten nutzen. Das verbesserte Konzept wird erstmals auf der Augmented World Expo Europe (AWE), vom 18. – 19. Oktober 2016, in Berlin, Stand B25 vorgestellt.

„Augmented Reality“ (erweiterte Realität) und „Wearable Displays“ (tragbare Displays) sind Schlagworte, denen man mittlerweile fast täglich begegnet. Beide...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Von der Probe zum digitalen Modell - MikroskopieTrends ´16

26.09.2016 | Veranstaltungen

300 Experten diskutieren auf größter Entrepreneurship-Konferenz im deutschsprachigen Raum

26.09.2016 | Veranstaltungen

Idealer Ablauf für GMP-konforme Projekte

26.09.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Phänotyp auf Knopfdruck

26.09.2016 | Biowissenschaften Chemie

Effiziente elektrische Antriebe: TU Graz startet Christian Doppler Labor

26.09.2016 | Maschinenbau

Methodenentwicklung an BESSY II: Automatische Auswertung beschleunigt die Suche nach neuen Wirkstoffen

26.09.2016 | Biowissenschaften Chemie