Featured Research

from universities, journals, and other organizations

Lunar Soil Yields Evidence About Sun's Dynamic Workings

Date:
October 15, 2001
Source:
Purdue University
Summary:
Soil collected on the moon by Purdue University alumnus Eugene Cernan nearly 30 years ago has helped researchers at his alma mater and the University of California uncover new details about the workings of the sun.

WEST LAFAYETTE, Ind. — Soil collected on the moon by Purdue University alumnus Eugene Cernan nearly 30 years ago has helped researchers at his alma mater and the University of California uncover new details about the workings of the sun.

Physicists at UC Berkeley and Purdue analyzed lunar soil samples for the presence of an element deposited on the moon's surface by the solar winds, a stream of particles constantly being ejected from the sun. The analysis revealed strong evidence that materials produced in the sun's atmosphere do not circulate farther into the interior of the sun before they are ejected, as some scientists have suggested. Instead, the materials are created in the atmosphere and then ejected directly outward, spreading throughout the solar system in the solar wind.

The findings will be reported in the journal Science on Friday (10/12), in a paper written by Kuni Nishiizumi, a researcher at UC Berkeley's Space Sciences Laboratory, and Marc Caffee, an associate professor of physics at Purdue.

The lunar soil was scooped up by Apollo 17 astronauts Cernan and Harrison Schmitt, who landed on the moon in 1972. They collected the largest lunar sample ever brought back to Earth — about 249 pounds of dirt now stored at the Johnson Space Center in Houston.

"The astronauts did a spectacular job," Caffee said, noting that robots are still no substitute for humans in space when it comes to completing complex assignments.

Cernan, who was the commander of Apollo 17, was the last man to walk on the moon. He earned a bachelor of science degree in electrical engineering from Purdue in 1956 and also holds an honorary doctorate from the university.

Nishiizumi and Caffee analyzed lunar soil for the presence of a radioactive form of the element beryllium called beryllium-10. Beryllium-10 is an isotope of beryllium; it contains four protons and six neutrons in its nucleus, unlike ordinary beryllium, which contains four protons and five neutrons. This radioactive, unstable form of beryllium decomposes in 1.6 million years, a period of time called its half-life. That means any beryllium-10 found in the lunar soil must have been deposited there long after the moon's creation, and much of it has come from the solar winds, Caffee said.

Beryllium-10 is produced in the sun's atmospheric layers — the chromosphere and corona — and eventually spewed out, along with numerous other constituents, in the solar wind.

"The sun is constantly shedding pieces of itself," Caffee said.

The Earth and other planets are shielded from the solar winds by their atmospheric envelopes and magnetic fields that surround some planetary bodies.

"The moon has no atmosphere and no magnetic field, so the solar wind is not kept in any way, shape or form from hitting the surface of the moon," he said.

The researchers extracted beryllium-10 from the lunar soil by treating the soil with nitric and hydrofluoric acids. Then, the precise quantity of beryllium-10 contained in the soil was determined by using a piece of equipment called an accelerator mass spectrometer.

The findings provided strong evidence that the beryllium, and therefore other constituents produced in the sun's atmosphere, are ejected shortly after they are produced in the atmosphere. Some researchers have suggested that materials produced in the sun's atmosphere are pulled into the sun's interior, where they circulate in convection currents for millions of years before making their way back to the sun's outer atmospheric layers.

The new findings contradict that theory, Caffee said.

Such findings will not only reveal details about the sun's workings, but they also will provide new insights into how the sun and the solar system were formed 4.5 billion years ago.

"Surprisingly, there are a lot of things we still don't know about the sun," Caffee said.

He and Nishiizumi are working on a new NASA mission called Genesis, a spacecraft launched this summer that will collect particles from the solar wind.

The spacecraft is expected to complete its mission within two years and return to Earth.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Lunar Soil Yields Evidence About Sun's Dynamic Workings." ScienceDaily. ScienceDaily, 15 October 2001. <www.sciencedaily.com/releases/2001/10/011012073750.htm>.
Purdue University. (2001, October 15). Lunar Soil Yields Evidence About Sun's Dynamic Workings. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2001/10/011012073750.htm
Purdue University. "Lunar Soil Yields Evidence About Sun's Dynamic Workings." ScienceDaily. www.sciencedaily.com/releases/2001/10/011012073750.htm (accessed October 21, 2014).

Share This



More Space & Time News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins