Solar System May Be Older Than Thought
2010-08-24 0:00

By Mike Wall | Space.com



The solar system may be up to two million years older than previously thought, a new study has found.

Researchers studying bits of a meteorite discovered that the space rock was 4.5682 billion years old, predating previous estimates of the solar systemís age by up to 1.9 million years. This adjustment, though ever so slight, should help astronomers better understand how the sun and planets formed.

"We believe that, right now, this is the most precise and accurate date for the age of the solar system," said study co-author Meenakshi Wadhwa of Arizona State University.

Meteorite detective story

Wadhwa and colleague Audrey Bouvier, also of ASU, made the find while studying a meteorite called NWA 2364, which fell to Earth in Morocco in 2004. They examined a 1-centimeter chunk of the meteorite known as a calcium-aluminum-rich inclusion, or CAI.

Inclusions are minerals that get trapped inside meteorites as the space rocks are forming. Scientists believe CAIís were among the first solids to condense out when the sun and planets were forming, so CAI ages are good representations of the solar systemís age.

Wadhwa and Bouvier used lead-lead dating, a technique commonly used to date meteorites, to figure out the CAIís age. They measured the abundances of three lead isotopes - versions of the element with different atomic masses - in the CAI. Two of the lead versions form when uranium isotopes radioactively decay; the other one is not a decay product.

Comparing the amounts of the three lead isotopes, and relating those numbers to the known rates of uranium-isotope decay, gave the researchers their answer: 4.5682 billion years.

This number is only a hair older than previous estimates of the solar systemís age, which were chiefly gleaned from dating CAIís in other meteorites. But the difference is real, according to Wadhwa.

"Thatís the power of geochemistry," she told SPACE.com. "You can make very, very precise measurements."

Age of the solar system

And even such small adjustments to the solar systemís age can be very important to astronomers seeking to understand how the sun and planets formed.

As an example, Wadhwa and Bouvier cite the abundance of the isotope iron-60 in the proto-solar system. Iron-60 is radioactive, with a half-life of about 2.6 million years. Every 2.6 million years, half of the iron-60 in a given sample decays away.

So if you push the age of the solar system back by about two million years, that means there was almost twice as much iron-60 present during its birth than previously thought. And this increased concentration has consequences: it strongly supports the idea that a supernova exploded nearby during the solar systemís formation, injecting huge quantities of heat that helped nascent bodies differentiate.

"Iron-60 is kind of a smoking gun," Wadhwa said. "If present in certain abundances, it can only really be there because of a supernova injection."

Astronomers can do this sort of sleuthing with many different isotopes that have relatively short half-lives. So nailing down the solar systemís age precisely is key.

"It gives us a better understanding of the type of environment the solar system evolved in," Wadhwa said.

The researchers report their findings Aug. 22 in the online version of Nature Geoscience.


Article from: Space.com

Image: Source




Related Articles
Hypergeometry, Astrology and the Spaces Inbetween (Video)
Violent spacequakes shake Earth from above
Age Confirmed for íEve,í Mother of All Humans
New Find Pushes Age of Stone Tools Back A Million Years!
Revised theory of gravity doesnít predict a Big Bang
Big Bang experiment may reveal dark universe: CERN
Andrew Lange, physicist who explored remnants of Big Bang, dies at age 52


Latest News from our Front Page

Pro-Israel bias: BBC admits editorial breach in interview with Israeli defense chief
2015-05-23 7:58
The BBC has reached a ‚Äúprovisional finding‚ÄĚ to uphold complaints made by Palestinian activists that the broadcaster breached its editorial guidelines in a ‚Äúsoft‚ÄĚ interview with the Israeli defense minister. Complaints focused on BBC journalist Sarah Montague‚Äôs alleged failure to challenge controversial claims made by Israeli Defense Minister Moshe Ya‚Äôalon. Journalist Amena Saleem, who works with the Palestine Solidarity Campaign (PSC), wrote ...
41% of Americans Support Criminalizing "Hate Speech"
2015-05-23 7:31
The following are from a recent poll about what some are calling on for "hate speech" 1. Support for Hate Crimes Legislation Do you support or oppose the federal law that requires increased penalties for hate crimes committed on the basis of the actual or perceived race, color, religion, national origin, ethnicity, or gender of any person? 2. Support for Expanding Hate Crimes Do ...
FBI Admits No Major Cases Cracked with Patriot Act Snooping Powers
2015-05-23 7:36
FBI agents can’t point to any major terrorism cases they’ve cracked thanks to the key snooping powers in the Patriot Act, the Justice Department’s inspector general said in a report Thursday that could complicate efforts to keep key parts of the law operating. Inspector General Michael E. Horowitz said that between 2004 and 2009, the FBI tripled its use of bulk ...
Sweetener Stevia Was Once Hailed As An Anti-Fertility Agent for Population Reduction
2015-05-23 7:13
Maybe it's not so sweet now... If you've thought stevia, the natural alternative to sugar and artificial sweetners with aspartame, et al., is too good to be true, there may be a catch. Check out this textbook written in 1970 by Paul and Anne Ehrlich, the precursor to the textbook Ecoscience they wrote with Obama Science Czar John P. Holdren ...
TPP Aproved: Senate Republicans Give Obama New Powers - Details Remain 'Classified'
2015-05-23 6:43
President Obama won a big victory for his trade agenda Friday with the Senate’s approval of fast-track legislation that could make it easier for him to complete a wide-ranging trade deal that would include 11 Pacific Rim nations. A coalition of 48 Senate Republicans and 14 Democrats voted for Trade Promotion Authority late Friday, sending the legislation to a difficult fight ...
More News »