南非學者表示他們發現大約2800萬年前彗星撞擊地球的證據—地點是埃及西部的一處沙漠。
科學家稱現場遺留的似玻璃般的黑色岩石為彗星碎片—這些物質可能有助於揭開我們宇宙的奧秘。
學者們本月在約翰尼斯堡金山大學展現了他們的研究結果。
流星，小行星和這顆行星的碰撞相當頻繁。
但威特沃特斯蘭德大學教授大衛·布洛克表示一次彗星撞擊非常罕見而且令人興奮。
“因為一顆彗星實際上就是一些冰雪物質和塵埃混雜在一起的髒雪球。
關鍵是原子,蘊含生命的原子，其中的碳,氧氣、氮氣、氬氣、氬、氪、都在這個太陽系以外的小化工廠中。”布洛克說道。
“這些都是早于我們太陽系形成的宇宙塵埃顆粒。
所以它們含有獨特氣體和灰塵化學混合成分的秘密，那是形成我們的太陽和行星圍繞著的物質。”
一些科學家認為可能是這顆彗星撞擊造成6500萬年前恐龍滅絕—但沒有證據。
而馬可·安德奧利博士表示沒有人曾目睹過彗星撞擊然後親身講述,因為它們會將阻擋其路的每個活物燃為灰燼。
儘管如此他表示這顆彗星的證據對他很明朗。
“我們正在尋找的是一次天文現象,”他說道。
約翰尼斯堡大學地學科學家讓·克雷默斯表示儘管科學界對於他團隊表明該碎片是一顆彗星的研究結論存在分歧,但他自己則十分肯定。
“這可能是一顆彗星,因為它不可能是別的什麼,來自太陽系外層邊緣,因為太陽引力的旅行及撞擊地球的偶然。
它帶給你的還有很多,”克雷默斯說道。
“當擊中大氣層時候發生了什麼,爆炸。
這就是當彗星衝擊大氣層時候的表現。
而這一爆炸產生大量的熱能,從而導致我們在利比亞沙漠地區發現的玻璃狀碎片。”
研究人員稱他們希望進一步研究這顆慧星碎片，這將幫助他們探秘我們宇宙的起源。
South African academics say the evidence they've found indicates the comet hit the earth some 28 million years ago-in a desert in western Egypt.
The bits of glassy black rock left at the scene-which scientists say are comet fragments-could help unlock the secrets of our universe.
The academics presented their findings at the University of the Witwatersrand in Johannesburg this month.
Meteors and asteroids collide with this planet fairly frequently.
But a comet strike, said Professor David Block of the University of the Witwatersrand, is unique and exciting.
“Because a comet is this dirty snowball of not only rock, but rock mixed with ice.
And the point is that atoms, life-giving atoms of carbon, of oxygen, of nitrogen, of argon, of neon, of krypton, are encoded within this little chemical factory from beyond the solar system," said Block.
"These are grains of cosmic dust, which existed prior to our solar system forming.
So they contain unique secrets of the chemical composition of the cloud of gas and dust, which collapsed to form our sun and the planets around it.”
Some scientists have theorized it may have been a comet strike that killed the dinosaurs 65 million years ago-but there is no evidence.
And, said Dr. Marco Andreoli, no one has seen a comet hit and lived to tell about it because they tend to fry every living thing in their path to ashes.
He said, though, the evidence of this comet strike is clear to him.
“We are looking at something of… an astronomical phenomenon,” he said.
Geoscientist Jan Kramers from the University of Johannesburg said that although the scientific community is divided on his team's conclusions that the fragment is a comet, he himself is fairly certain.
“… it's a probably a comet, because it can't be anything else, coming from the outermost reaches in the solar system, traveling in the gravity of the sun and hitting the Earth by chance.
What it did tells you something more," said Kramers.
"What it did when it hit the atmosphere, it exploded.
And that is what comets do when they hit the atmosphere.
And this explosion produces an incredible amount of heat, which can account for the Libyan desert glass which we found in that region.”
The researchers say they hope further study of this comet fragments will help them figure out the beginnings of our universe.
