Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Space scientist proposes new model for Jupiter’s core

14.12.2004


The planet Jupiter may have a core of tar, according to new reasearch from WUSTL.


After eleven months of politics, now it’s time for some real "core values" - not those of the candidates but those of the great gas giant planet, Jupiter.

The planet Jupiter may have a core of tar, according to new reasearch from WUSTL.
Katharina Lodders, Ph.D., Washington University in St. Louis research associate professor in Earth and Planetary Sciences in Arts & Sciences, studying data from the Galileo probe of Jupiter, proposes a new mechanism by which the planet formed 4.5 billion years ago.


The widely accepted model for Jupiter’s formation assumes that its overall composition is similar to that of the Sun, with enrichments of oxygen and other elements heavier than helium. Jupiter’s core was believed to be a massive snowball that formed in the cold reaches of the outer solar nebula, the gas and dust cloud from which the solar system formed. However, the Galileo probe mass spectrometer found much less water than expected in Jupiter’s atmosphere.

Taking the mass spectrometer data and earlier Earth-based infrared spectroscopic measurements at face value, Lodders calculated that Jupiter is depleted in water and thus in oxygen. The Jovian oxygen inventory is only about half of the oxygen elemental abundance in the Sun. On the other hand, the Galileo probe mass spectrometer data show that Jupiter’s carbon inventory is about 1.7 times larger than that in the Sun. Based on these data, Lodders argues that Jupiter’s core was mainly tar instead of ice.

Snow line yields to tar line

Lodders’ theoretical model assumes an outer solar system warmer than previously thought. Her theory replaces what astronomers call the "snow line," the point in the solar nebula where water ice condenses, with the new "tar line," the point where asphalt or tar-like material formed, pushing the snow line farther out in the solar nebula.

Picture a snowy street in winter and a fresh layer of tar on part of that street.

"Snow will evaporate with warmer temperatures but the tar will stay" said Lodders. "Also consider the fact that organics make a kind of sticky goo, which is good for gathering rocks and building the core. Imagine an ice cube and sticking bits of rock to it, then think of maple syrup. What’s going to have better sticking properties?"

Jupiter’s core formed rapidly relative to the rate at which gas was lost from the solar nebula. Once its core reached about 10 Earth masses, gravitational attraction captured the surrounding nebular gas and built up the gas giant planet we observe today. The core question, if you will, is: If there was a lot of water ice that helped to built the Jovian core, where is the water now?

"My thinking is to look at the (Galileo) data, accept them and come up with a new theory, a new model instead of fitting the observations to the older model," said Lodders. "It’s always bad, though, if you reject a model and don’t come up with a better one. "

Portrait of a dry planet

The observations indicate that water is depleted on Jupiter. "If there never was much water ice you never expect to observe much water in the atmosphere now," said Lodders. "However, you need to build a large proto-core fast, because otherwise you don’t have enough mass there to accrete gas and to make a gas giant planet."

But Jupiter is enriched in carbon, and Lodders notes that there is much evidence for carbon being locked up in organic material on outer solar system planets, comets, and meteorites, and the interstellar medium from which our solar system originated.

Lodders proposes that the Jovian core is originally tar and rock, steadily growing to the point where it accretes gas from the solar nebula, primarily hydrogen and helium. Energy from the accretion heats up Jupiter, reacting the tar and making methane, the third most abundant gas observed in the planet’s atmosphere after hydrogen and helium.

"Up to fifty percent of the carbon in the interstellar medium may be in organic solids," she pointed out. "Organic solids are abundant out there and Jupiter is enriched in carbon, so it makes sense to assume that organic solids - instead of water ice - provided the glue to rapidly build the proto Jovian core."

Lodders described her new model at the annual meeting of the Division of Planetary Sciences of the American Astronomical Society in Louisville, Kentucky, from Nov. 8-12, 2004, and in the Aug. 10, 2004 issue of the Astrophysical Journal.

Tony Fitzpatrick | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Physics and Astronomy:

nachricht European XFEL prepares for user operation: Researchers can hand in first proposals for experiments
24.01.2017 | European XFEL GmbH

nachricht PPPL physicist uncovers clues to mechanism behind magnetic reconnection
24.01.2017 | DOE/Princeton Plasma Physics Laboratory

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: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Arctic melt ponds form when meltwater clogs ice pores

24.01.2017 | Earth Sciences

Synthetic nanoparticles achieve the complexity of protein molecules

24.01.2017 | Life Sciences

PPPL physicist uncovers clues to mechanism behind magnetic reconnection

24.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>