2011-04-01

拍案驚奇之宇宙篇

Elusive Ring of Earth Unveiled by JWST

The newly launched 2.4 billion dollar James-Webb Space Telescope (JWST) once again surprises the world in its first month of operation. This time it is something in our backyard. A ring around us.

"It is totally unpredictable," said C. Feldman, the chief scientist of the project. "All of us thought of the optical defects of Hubble's type at a first glance, but with cross checking we are convinced that there is nothing wrong with the instruments."

Earth has a large moon instead of two, it is common sense. Saturn has a spectacular ring while Earth has none, it is also common sense. But now JWST says NO. With the image taken by the Near Infrared Camera (NIRcam) as shown below, we now have a completely new picture of our home planet.

"We have limited visions," said Feldman, "which only covers a narrow range of electromagnetic spectrum". "We have to go IR for objects which are either too cold or covered by something cold, and that's why JWST works in this range".

JWST shows that the ring of Earth is made of carbon powders like those we find in cigarette butts, which reflects no light, and therefore invisible to human eyes. Hypothesis are proposed to recounstruct the way such amount of carbon managed to get there, its spread along the Earth-bound orbit.


地球軌道驚現光環 新型望遠鏡揭示看不見的宇宙

耗資達24億美元(約187.2億港元)的詹姆斯·韋伯望遠鏡(James-Webb Space Telescope, JWST)升空不足一個月已陸續帶來驚人消息。今次的發現不在宇宙深處,卻在我們每個人的頭上——地球上空掛著光環。

計劃的首席科學家費爾德曼指這是出乎意料之外的發現。「控制室內眾人不約而同想起哈勃望遠鏡的光學缺陷,但重重證據都顯示問題不在儀器之上。」

人人都知道地球有一顆衛星,沒有光環。隨著詹姆斯·韋伯望遠鏡的近紅外線攝影機(Near Infrared Camera, NIRcam)傳來最新的照片,我們對自己的行星將會有全新的認知。


「我們的視力很有限,只看到整個電磁波譜的一小部份。要看宇宙中溫度極低的區域,我們必須從紅外線著手。亦正因如此,詹姆斯·韋伯望遠鏡要在這一波段運作。」


分析指地球的光環主要成份是碳粉。由於碳粉完全不反射陽光,因此肉眼不會看到。目前科學家仍在提出假設,重組這些碳粉被灑落在地球軌道的過程。

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