Social Media Sidebar

Announcement

Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

When seen through the lens of technology, few resources are truly scarce; they’re mainly inaccessible. 

 

Peter Diamandis

Aging Stars Can Make New Habitable Zones For Planets

RATE THIS! +23
Posted in Science on 29th May, 2016 01:04 PM by AlexMuller

As our Sun gets older, brighter, and bigger over the next several billion years, it will expand into a red giant so large that its heat could melt ice on the surface of Europa and the other moons of Jupiter, as well as those around Saturn. Liquid water flowing freely would provide a stable environment ripe for fostering life.

 

The bad news is Earth will be burnt to a crisp. It may even get engulfed by the fiery wall of the expanding star, along with Mercury and Venus, so anyone that remains on Earth probably won’t live to see that day.

 
For right now, however, humans who study planets orbiting other stars stand to benefit from the grim future prospects of our solar system’s innermost planets. A new model of the evolution of stellar systems’ habitable zones, based on what’s expected for our own solar system, could help observers today better evaluate which exoplanets could harbor life.
 
In a solar system’s habitable zone, enough energy and heat from the central star sustain liquid water on its orbiting planets. Using their new model, researchers at Cornell University’s Carl Sagan Institute in Ithaca, N.Y., have found that the habitable zones around stars that have aged into red giants may exist for perhaps billions of years after the star’s expansion.
 
In this time span, primordial life could perhaps evolve and flourish, said Ramses Ramirez, a planetary scientist at the institute. Ramirez and colleagues describe their model in a paper published today in the Astrophysical Journal.
 
Currently, our Sun exists in its main sequence of stellar evolution. A churning engine of nuclear fusion converting hydrogen into helium in its core gives the Sun the fuel it needs to send enough energy hurtling toward Earth to sustain liquid water, a thick atmosphere, and life.
 
But in the next 7–7.5  billion years, the Sun will run out of hydrogen. The inward pressure of gravity will contract our star, and its internal pressure will allow helium to fuse into heavier elements like carbon, the higher core temperatures will cause the Sun to expand like a hot balloon, possibly to more than 200 times its current size. By the time the Sun is about 12.5 billion years old, it will have transformed into a red giant.
 
Under those future conditions, moons that orbit Jupiter and Saturn in zones that currently receive about 1/25 and 1/90 the Sun’s energy, respectively, will suddenly be in a habitable zone. Ramirez’s new model found that planets could reside in this new zone for 200 million to 9 billion years. Given that life on our planet took around 500–700 million years to evolve from simple multicellular organisms into more complex forms, Ramirez said, life on the once-icy moons could possibly flourish.
 
Astronomers learn about exoplanets’ surface compositions by splitting the light emitted by the planet into its component wavelengths, from the smallest gamma rays through the longest radio waves. Patterns over this light spectrum can then be matched to known patterns of emissions produced by various elements or molecules. In this way, scientists estimate the chemical “fingerprint” of an exoplanet’s surface.
 
So far, those looking for worlds that could harbor life generally search for Earth-like rocky planets orbiting a star’s habitable zone. But if Europa-like analogs exist in other stellar systems, the new study widens the search parameters, opening up new possibilities to consider in systems with older stars, Ramirez said.
 
The resulting larger pool of exoplanets could then be analyzed to see if their surfaces hold not only water but also gases such as oxygen, methane, and carbon dioxide. Such gases indicate the presence of an atmosphere, which is also important to retaining life.
 
The trick now, Ramirez said, will be pointing our telescopes in the right direction.

Tags: planetlifebiologyspaceastronomyresearch

Read original article » Back to category

Comments



 

Recent headlines

  • Posted in Online on 2017-12-15 13:43:41
    The FCC votes to repeal the 2015 net neutrality rules..read more
    Posted in Science on 2017-12-15 13:34:37
    How Clinical Trials Are Making the Case for MDMA in.....read more
    Posted in Business on 2017-12-15 13:23:01
    Elon Musk: We Should Already Have a Lunar Base by Now..read more
    Posted in Business on 2017-12-14 01:48:06
    World Bank to stop financing oil, gas projects from 2019..read more
    Posted in Medicine on 2017-12-13 21:23:13
    Marijuana May Help HIV Patients Keep Mental Stamina Longer..read more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in about.....read more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for commercial.....read more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 Downloads..read more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into new.....read more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs,.....read more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for commercial.....read more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short Sighted..read more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, but.....read more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in about.....read more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target mitochondria..read more

Recent Blog Posts

  • Posted by AlexMuller
    Martian landscapes formed from sand 'levitating' on a little.....read more
    Posted by AlexMuller
    Scientists detect comets outside our solar system..read more
    Posted by AlexMuller
    Advanced artificial limbs mapped in the brain..read more
    Posted by AlexMuller
    Bacteria have a sense of touch..read more
    Posted by AlexMuller
    Recurrent brain cancer: New hope with phase 1 clinical trial.....read more

Login to your Account

Login to your PlanetTech Account here

Username:
Password:
Remember me
or

Create a New Account

You just need username and password

The following errors occured:
Username:
Email:
Password:
Verify password:
Remember me