Glimpse at Swollen Stars Hints at Earth's Demise

[kai_25]

Today's global warming is nothing compared to what astronomers have just seen through the time machine of a telescope.<br /><br />The most detailed look ever at the environments very near the surfaces of several aging and bloated stars reveals a potentially - future for Earth. Because the stars are older versions of the one that gives us warmth, the measurements help astronomers envision what will happen in a few billion years, when the swollen Sun will scorch Earth.<br /><br />The dying objects are called Mira stars, for one of the most famous of the bunch. They are part of a broader class of object known as red giants, which include the popular skywatching targets Betelgeuse (often pronounced "beetle juice") and Antares, both considered red supergiants.<br /><br />Mira stars have nearly exhausted the hydrogen that powers their thermonuclear furnaces. Each is swelled to a diameter that is larger than the orbit of our home planet. The aging stars pulsate, expanding and contracting every year or so. <br /><br />When our Sun begins to pulsate, the surface temperature on Earth will periodically climb to 5,400 degrees Fahrenheit (3,000°C), said Guy Perrin, a Paris Observatory researcher who led the new study. <br /><br />"The direct consequence is that no life will be possible by then on Earth," Perrin told SPACE.com . "But this is in a few billion years from now."<br /><br />It is also one reason why Perrin and his colleagues eagerly study Mira stars, whose intense activity has prevented views of their surfaces.<br /><br />The new work combined several telescopes to effectively create one large observatory in a technique called interferometry, allowing a look at each stars photosphere, the area just above the surface.<br /><br />"During these pulsations, Mira stars lose a lot of mass to the interstellar medium," Perrin explained. Material equal to about a third of the Earth is pumped into interstellar space with each pulsation. Scientists don't know exactly how all this works.<br /><b></b>

 

[nexium]

Is there any other reason than math to think these red giant stars were once G, K or M type main sequence stars like our Sun? Perhaps this is the fate of some G stars, but not others. How many gigawatt hours are needed to move Earth to a circular orbit with a radius of one billion kilometers. 10E88 perhaps? Neil

 

[grooble]

These doomsday predictions are silly. In a billion years our technology will make us god like, we'll be able to create or destroy our own Suns. <br /><br />In fact i bet we'll have that capability in less than 5,000 years.

 

[scottb50]

That's pretty presumptuous if you ask me. In a couple of billion years we have only gained a foothold on controlling our environment. In fact, we are presently doing a very good job of destroying it, and have no idea, or desire to save it. <br /><br />I think creating or destroy Suns will remain outside our grasp. First we have to figure how to get to another Sun outside our solar system, let alone create them. At the rate we have been going Earth will be toast before we can get somewhere else.<br /><br /> <div class="Discussion_UserSignature"> </div>