Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neighbors' Weird Orbits Can Make 'Habitable' Planets Not So Habitable

25.05.2010
Astronomers hunting for planets orbiting nearby stars similar to the sun are looking for signs of rocky, Earth-like planets in a "habitable" zone, where conditions such as temperature and liquid water remain stable enough to support life.

New findings from computer modeling indicate that some of those exoplanets might fluctuate between being habitable and being inhospitable to life because of the forces exerted by giant neighbors with eccentric orbits.

A lone Earth-like, or terrestrial, planet with a generally circular orbit toward the inner edge of its sun's habitable zone could be expected to remain within that zone, said Rory Barnes, a University of Washington postdoctoral researcher in astronomy. Adding a planet comparable to Jupiter to the system, however, and giving it a highly elliptical orbit – similar to most exoplanets discovered so far – can cause strange things to happen to the smaller planet, possibly causing it to cycle between habitable and uninhabitable conditions.

The smaller planet's orbit will elongate and then become more circular again, all in as little as 1,000 years, and could do so repeatedly. That raises the possibility, for example, that its average yearly temperature could change significantly during each millennium.

"For part of the time liquid water could exist on the surface, but at others it would boil off," said Barnes, who will present the findings Wednesday at a meeting of the American Astronomical Society in Miami.

The effect would be similar for an Earth-like planet at the outer edge of its habitable zone, except that its altered orbit likely would, at times, take it too far from its star, possibly resulting in planetary glaciation.

"The bigger issue here is that the habitable zone is very complicated," Barnes said. "Earth's climate is affected slightly over tens of thousands of years by the orbits of other planets in the solar system, but it is possible that in many exoplanetary systems the layout of the planets is very important to habitability."

The problem becomes even more complex for what could be habitable planets orbiting low-mass stars, perhaps one-third the mass of the sun. In such systems, the habitable zone is much closer to the smaller star, and tidal forces from the star's gravity are critical in determining whether the planet is habitable. Adding an eccentric orbit of a Jupiter-like planet could greatly alter conditions on the smaller planet as its orbit changes.

"There could be planets out there that have their geological properties change over very long timescales," Barnes said. "You can imagine planets that cycle in and out of intense volcanism and earthquake stages."

Tidal forces also fix the planet's rotation period, and as the orbit becomes more elongated the length of day can change significantly, Barnes said.

"The length of the day changes almost day to day," he said. "It's fascinating to think about how evolution occurs on such a world."

The work, funded by NASA's Virtual Planetary Laboratory, was conducted with Brian Jackson of NASA's Goddard Space Flight Center, Richard Greenberg of the University of Arizona and Sean Raymond of the Laboratoire d'Astrophysique de Bordeaux in France.

"There is this crazy zoo of planets out there that probably are habitable," Barnes said, "but their properties are very different from Earth and they're different from Earth because of their eccentric neighbors."

For more information, contact Barnes at 206-543-8979 or rory@astro.washington.edu.

NOTE: During the AAS meeting, Barnes can be reached by leaving a message at the AAS press room, 305-679-3276 or 3277.

Vince Stricherz | Newswise Science News
Further information:
http://www.uw.edu

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>