1)Meteorites on the ground or icy comets millions of miles away are usually the only sources of ancient matter from the early days of the solar system.

But in a high-flying experiment， researchers have used a sort of chemical 2)flypaper to 3)scoop up comet dust from Earth’s atmosphere – and it appears to be some of the oldest matter in our cosmic neighborhood.

The ancient specks， some of which are more than 4.5 billion years old， may support the theory that an exploding star helped 4)trigger the birth of our sun.

The dust has survived in an 5)unaltered state for so long because it got swept up during the formation of icy comets， researchers say.

“Comets are like refrigerators for this material，” said study leader Henner Busemann， an 6)astrophy-sicist at the University of Manchester in the U.K.

“They store this very 7)pristine material， which never changes again.”

Dust from the Sun’s 8)Nursery Busemann and colleagues collected the particles in April 2003， as Earth spun through the dusty tail of comet 26P/Grigg-Skjellerup.

The team asked NASA to fly an airplane at about 12 miles (20 kilometers) up for several hours during the comet’s visit， using instruments equipped with silicon oil to capture particles trapped in the upper atmosphere.

By comparing the dust to samples collected from comet-9)smashing 10)probes such as Deep Impact and Stardust， the scientists were able to tell that the particles in Earth’s atmosphere came from 26P/Grigg-Skjellerup.

The team’s analysis also shows that two of the grains have a unique chemical fingerprint linking them to the huge gas cloud. Scientists think it was our sun’s 11)stellar nursery.

Also， one of the dust particles contains grains of material that match predictions for the types of matter expected to form in the cooling gas left over after a 12)supernova explosion.

Scientists have 13)speculated that 14)shockwaves from a nearby supernova helped trigger the birth of our sun， and some of the comet material could have originated from that blast， Busemann said.

The astrophysicist presented his research this April at the European Week of Astronomy and Space Science conference at the University of Hertfordshire in the U.K.

地面上的隕星或幾百萬英里外的冰狀彗星往往是太陽系初期遠(yuǎn)古物質(zhì)的唯一來源。

不過，在一項(xiàng)高空飛行的實(shí)驗(yàn)環(huán)境下，研究人員使用了一種化學(xué)“捕蠅紙”收集到來自地球大氣層的彗星塵?！赡苁俏覀兊挠钪驵徲蛑凶顬楣爬系奈镔|(zhì)。

部分遠(yuǎn)古塵埃已有超過45億年的歷史。這也許能支持“某一恒星的爆炸促成了太陽系的誕生”此理論假說。

研究人員稱，這種塵埃在恒定不變的狀態(tài)下存活了非常長(zhǎng)的時(shí)間，因?yàn)樵缭诒鶢铄缧切纬傻臅r(shí)候，它就被清理一新了。

“彗星就像是儲(chǔ)存這種物質(zhì)的冰箱，”來自英國(guó)曼徹斯特大學(xué)的天體物理學(xué)家、研究組負(fù)責(zé)人亨納·布茲曼說。

“它們將這種遠(yuǎn)古的物質(zhì)儲(chǔ)存起來，這些物質(zhì)再也不會(huì)發(fā)生變化了。”

來自太陽溫床的塵埃

2003年4月，當(dāng)?shù)厍蛐D(zhuǎn)經(jīng)過格里格-斯克杰利厄普彗星的塵埃尾部時(shí)，布茲曼及其同事收集了一些粒子。

在該彗星經(jīng)過地球期間，研究小組請(qǐng)美國(guó)國(guó)家航空航天局(NASA)發(fā)射一架航天飛機(jī)，在大約12英里(20公里)高的高空飛行幾小時(shí)，用裝有硅油的設(shè)備捕獲被誘入大氣層上部的粒子。

通過將這種塵埃與從彗星破碎探測(cè)器如“深度撞擊號(hào)”和“星塵號(hào)”等收集來的樣本進(jìn)行比較，科學(xué)家們得出結(jié)論，這些出現(xiàn)在地球大氣層的粒子均來自格里格-斯克杰利厄普彗星。

該研究小組的分析還顯示，其中兩個(gè)顆粒上擁有與大型氣體云有聯(lián)系的獨(dú)特化學(xué)“指紋”。科學(xué)家們認(rèn)為這種氣體云是孕育太陽的溫床。

此外，其中一個(gè)塵埃還包含了一些物質(zhì)顆粒，這些顆粒證實(shí)了對(duì)超新星爆炸后留存下來的冷卻氣體中形成的物質(zhì)類別的預(yù)測(cè)。

布茲曼說，科學(xué)家們猜測(cè)，來自一顆鄰近超新星的沖擊波促成了我們太陽系的誕生，一些彗星物質(zhì)可能產(chǎn)生于這次大爆炸。

今年四月，這位天文物理學(xué)家在英國(guó)赫特福德大學(xué)舉行的歐洲天文周和太空科學(xué)大會(huì)上展示了他的研究結(jié)果。