Ancient star raises prospects of intelligent life

May 7, 2015 by Elizabeth Howell
Ancient star raises prospects of intelligent life
Artist’s conception of Kepler-444 and its five orbiting planets. Credit: Peter Devine and Tiago Campante/University of Birmingham

Can life survive for billions of years longer than the expected timeline on Earth? As scientists discover older and older solar systems, it's likely that before long we'll find an ancient planet in a habitable zone. Knowing if life is possible on this exoplanet would have immense implications for habitability and the development of ancient life, one researcher says.

In January, a group led by Tiago Campante—an astroseismology or "starquake" researcher at the University of Birmingham in the United Kingdom—announced a discovery of five tiny, likely rocky worlds close to an ancient star. The star is named Kepler-444 after NASA's planet-hunting Kepler mission, which first made a tentative discovery.

Campante's contribution was narrowing down the age of Kepler-444 and its to an astounding 11.2 billion years old. That's nearly 2.5 times as old as our solar system. None of Kepler-444's planets are thought to be habitable, as they circle the star at a scorchingly-close distance. However, Campante said that finding those planets is a great stride forward in the search for older, habitable worlds and the best may be yet to come.

"This system gives us hope that there are other habitable worlds that we can't detect because we don't have enough observing timespan yet," Campante said.

Upcoming observatories could change that, he added. But whether life can live for billions of years, however, is pure speculation.

"If intelligent life develops in a system as old as this one, would it still exist or would they extinguish themselves?" Campante asked.

Artist’s conception of Earth’s solar system (not to scale). Credit: NASA/JPL

Results from Campante's paper were published in January in the Astrophysical Journal in a paper entitled, "An Ancient Extrasolar System with Five Sub-Earth-Size Planets."

Surprise composition

The star is deficient in iron but is rich in what are called "alpha elements," such as silicon, carbon, nitrogen and oxygen. These elements were all formed in the first stellar explosions of our universe, when older stars ran out of fuel to burn and spread these elements far and wide. These elements make the composition of the star's orbiting planets a bit of a surprise, Campante said.

Normally, scientists expect that so-called "terrestrial" planets—rocky ones such as Mercury, Venus or Earth—to have lots of iron in their interiors. This discovery shows it's also possible to create planets that are primarily made of alpha elements, he said. This means that rocky planets may be able to form in multiple ways, making them more common across the Universe.

Kepler-444's system is not much like ours, though. Kepler-444 is slightly smaller than our sun, and its planets orbit extremely close in. The in this system starts around 0.4 astronomical units (AU), or Earth-Sun distances. Yet the outermost planet huddles at only 0.08 AU. That's roughly five times closer than Mercury is to our own sun.

Scientists learned more about the age and nature of the solar system by looking at pulses within the parent star. Credit: NASA

Widening the search

There are few known solar systems that are as old as Kepler-444. One huge informally known as "Methuselah" was discovered in the early 2000s. When the finding was announced in 2003, astronomers said the planet was roughly 12.7 billion years old, more than twice Earth's age.

Last year, astronomers said they had found two planets orbiting the 11.5-billion-year-old Kapteyn's Star, which is named after a Dutch astronomer. Both Kapteyn b and c are likely of a size between super-Earths and mini-Neptunes, Campante said.

Another ancient was found orbiting Kepler 10, which is roughly 10.6 billion years old, but the two planets were also not considered to be habitable. At the time of their discovery in 2011, the researchers described the planets as "a hot rocky world and a solid Neptune-mass planet."

It will take more powerful observatories to find more Earth-like worlds, Campante said, but luckily two are on their way shortly.NASA plans to launch the Transiting Exoplanet Survey Satellite (TESS) in 2017 and The European Space Agency will send PLATO (PLAnetary Transits and Oscillations of Stars) up in 2024. Campante is involved in the planning of PLATO.

Like Kepler, PLATO will search for Earth-like worlds around Sun-like stars, but it will sport a wider field of view and a more sensitive receiver. Both features could potentially detect more worlds, Campante said. TESS, meanwhile, will focus on stars closer to Earth, making them easier to track with ground-based observatories.

Explore further: Ancient star system reveals Earth-sized planets forming near start of universe

More information: "An Ancient Extrasolar System with Five Sub-Earth-size Planets." 2015 ApJ 799 170. DOI: 10.1088/0004-637X/799/2/170

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14 comments

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gkam
3.7 / 5 (11) May 07, 2015
I'm still looking for intelligent life on Earth.
syndicate_51
4 / 5 (4) May 07, 2015
There have been planets located in the goldilocks zone not only of their star but the galaxy as well. This imporves the odds, but their is still a lot more criteria to fulfill before it can be declared habitable.
michael_frishberg
2.3 / 5 (6) May 07, 2015
Forgive me, but, here's the good news!

Our type of intelligence here on Earth, if it has evolved anywhere, will have already gone extinct, as humans will do within 100 years.

Our intelligence, individually, is remarkable, but, in groups we cannot act with wisdom.

Nothing humans do is sustainable, ecologically speaking, and, since we won't regulate our population, we'll basically eat the entire protein production of the planet in a very few years, and then Nature will continue on without us.

Enough good news.

The bad news: We Have Already Lit Our Own Funeral Pyre, polluting the atmosphere, water and land, thereby orchestrating the most rapid and devastating extinction event in 250 million years.

Both the sardine (Pacific) and cod (Atlantic) fishing fleets were called in, due to lack of fish in 2015...just wait until 2050, when 2 or maybe 3 billion more of us exist on the planet.

It's immoral for anyone anywhere to have kids anymore.

vhemt.org
DavidTheShepherd
1.7 / 5 (10) May 08, 2015
@Michael, "It's immoral for anyone anywhere to have kids anymore"
If you don't believe in the God of Abraham, Isaac and Jacob, then there is no true fundamental reason to subscribe to any moral system. Hence it isn't immoral to have kids.
In a purely materialistic worldview, no basis for morality exists since there is no Super Being who created everything and to whom one is then accountable.
Thus what one person regards as moral in the materialistic world, another could see as immoral.

It might be unwise to continue having more than one child per couple but that is a completely different story.
Joker23
3.7 / 5 (3) May 08, 2015
Mister Frishberg is proof that some old ideas never did. Malthus said something similar in 1798. Civilizations as great and perhaps greater than ours have risen and fallen for over 10,000 years.Sumerians, Babylonians, Egypt, Rome, Inca, Mayan and may others. these assumptions, quite arrogant, assume our civilization will somehow be exempt from the fate of past civilizations. Just look at the forces and crazies dedicated to and trying to bring on Armageddon in today's world and the inept and impotent response to the threat. Repeating the impotent response to the Fascism of the Nazi in 1939.
Torbjorn_Larsson_OM
5 / 5 (3) May 08, 2015
Doomist cults are as boring as utopists. It is hard to predict, especially the future. And this is the first global civilization and the first age of science. (Which _does_ enable future prediction, for the first time.) But Gapminder statistics tells us, like Pinker's analysis of violence, that the global society is observably improving. Fast!*

Of course humans will go extinct. All species do eventually, and the average lifetime for a mammalian species is 1 Myrs. But Homo, especially Erectus, have existed longer than that.

"Our intelligence, individually, is remarkable, but, in groups we cannot act with wisdom."

But the observed fact is that groups, such as the science community, is smarter than individuals.

* If you want a _real_ reason for worry, is that no one knows yet why. Unless there is a forcing, like how humans have always socialized themselves, it can easily revert to the other direction.
EnsignFlandry
5 / 5 (5) May 08, 2015
It is a fallacy to think that intelligent life has to be similar to humans, with our aggressive nature and difficulties in working together. There is no innate reason for a civilization to destroy itself. An intelligent civilization could be 10 million years old. Natural hazards would be more of a threat than self-destruction until they got off their planet.

For that matter, people have been predicting the end of our own civilization for thousands of years. I think we will surprise ourselves.
EnsignFlandry
4.6 / 5 (10) May 08, 2015
@Michael, "It's immoral for anyone anywhere to have kids anymore"
If you don't believe in the God of Abraham, Isaac and Jacob, then there is no true fundamental reason to subscribe to any moral system. Hence it isn't immoral to have kids.
In a purely materialistic worldview, no basis for morality exists since there is no Super Being who created everything and to whom one is then accountable.
Thus what one person regards as moral in the materialistic world, another could see as immoral.

It might be unwise to continue having more than one child per couple but that is a completely different story.


People who believe in the Abrahamic god don't agree on what is moral. That's why there are a thousand churches and cults. It is possible to have a moral code without thinking it was arbitrarily dictated by a supernatural ghost. Just because you have to have Someone tell you what is right and wrong doesn't mean everyone does.
gkam
5 / 5 (4) May 09, 2015
Why do we need to invent these imaginary beings? What kind of terrible insecurity drives us to such actions?

I have an idea: Let's all divide into groups, invent imaginary beings, invest them with ridiculous powers, create entire legends around them, then we can kill each other over whose Imaginary Being is the "real" one.

We will not survive as a species unless we learn to outgrow this pathetic need.
antigoracle
1 / 5 (2) May 09, 2015
I'm still looking for intelligent life on Earth.

Well, you need to get out from, in front that mirror.
sirchick
5 / 5 (1) May 10, 2015
I'm still looking for intelligent life on Earth.

Well, you need to get out from, in front that mirror.


Works better if you construct your response with proper English. Otherwise, good effort.
gkam
not rated yet May 10, 2015
"Works better if you construct your response with proper English. Otherwise, good effort."
-------------------------------------------

And he's been working on that one for months now, . . .
antigoracle
1 / 5 (2) May 10, 2015
I'm still looking for intelligent life on Earth.

Well, you need to get out from, in front that mirror.


Works better if you construct your response with proper English. Otherwise, good effort.

Please, wise one, show me.
sirchick
5 / 5 (1) Jun 01, 2015
I'm still looking for intelligent life on Earth.

Well, you need to get out from, in front that mirror.


Works better if you construct your response with proper English. Otherwise, good effort.

Please, wise one, show me.


Try a high school.

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