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 Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

nachricht NASA team finds noxious ice cloud on saturn's moon titan
19.10.2017 | NASA/Goddard Space Flight Center

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>