Cat's Eye Nebula 貓眼星雲 (3/6/2003)
這是一張我很喜歡的行星狀星雲相－貓眼星雲。甚麼是行星狀星雲？它是恆星年老時吐出的氣殼，就以貓眼星雲為例，你見到它有幾個圈包圍著中間那顆星嗎？中間那顆就是那面臨死亡的恆星，而那一圈二圈就是它早前吐出來的氣殼。

Caption:: This Hubble telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the "Cat's Eye Nebula." Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas, and unusual shock-induced knots of gas. Estimated to be 1,000 years old, the nebula is a visual "fossil record" of the dynamics and late evolution of a dying star. A preliminary interpretation suggests that the object might be a double-star system. The dynamical effects of two stars orbiting one another most easily explains the intricate structures, which are much more complicated than features seen in most planetary nebulae. The two stars are too close together to be individually resolved by Hubble and instead appear as a single point of light at the center of the nebula.

Credit:: J.P. Harrington, K.J. Borkowski (University of Maryland), and NASA

The Trifid Nebula 三葉星雲 (2/6/2003)
這是位於人馬座的三葉星雲，又名三裂星雲和M20，這個名源自它的外觀，好像由三塊不同的東西所構成似的。這個星雲也是天文愛好者喜愛的對象，而這張相是由位於夏威夷的「加拿大．法國．夏威夷望遠鏡」所影的。原來星雲的顏色也有學問，你可以見到三葉星雲主要分為紅色和綠色（平時的相是藍色）兩部份，其實紅色就是星雲自己發光的地方，而綠色（藍色）則是反射星光的地方。

Caption:: The Trifid nebula (Messier 20), named after its three-lobed appearance caused by dusy lanes crossing its bright core, is a combination of an emission nebula and a reflection nebula. The blue color comes from the light of very bright, young stars that is being scattered by dust in the outskirts of the nebula. Radiation pressure from these young stars has created the central cavity by blowing away the dust and hydrogen. It lies at a distance of 5200 light years.

Credit:: Jean-Charles Cuillandre and CFHT

The Andromeda Galaxy 仙女座大星系 (1/6/2003)
早前提過仙女座大星系的銀暈，但沒有介紹到什麼是仙女座大星系，今次可以跟大家說，這個就是了。它是人類單靠肉眼看到最遠的東西，但在天文上的距離來說，它卻是一個很近我們居住的銀河系的星系。夏秋的時候，望上去仙女座的位置，留心一點的話（但當然要是好天啦），可以看到它的，跟其他深空天體一樣，它是十分濛的。這張是一張我很喜歡的M31的相，（忘記了跟大家說，仙女座大星系又名M31）很多人都影過M31，但我覺得這張的顏色最特別。

Caption:: The Andromeda Galaxy is a gigantic collection of more than 300 billion stars. Easily visible from a dark site, it is probably the farthest object that can be seen with the unaided eye, at a distance of about 2.93 million light years. Companion dwarf elliptical galaxies M32 and M110 are also visible, as well as NGC 206, a stellar association located inside of M31 and seen here as a bright knot of stars in the outer spiral arm at lower left. With the Hubble Space Telescope, it has been discovered that M31 has a double nucleus, probably because of an encounter with a smaller galaxy in the local group that it consumed. M31 is a member of our local group of galaxies. which also contains the Milky Way, Magellanic Clouds, and M33. In this photo, two different types of stellar populations are well differentiated. Young blue population I stars are seen in the outer arms, and old population II stars are seen as reddish colored in the central bulge of the galaxy.

Credit:: Jerry Lodriguss

Mars Exploration Rover 火星探索漫遊者號 (31/5/2003)
昨日介紹過火星特快號，是6月發射前往火星的探測船的中其中一艘，而另外2艘是今次介紹的火星探索漫遊者一號和二號。這是由美國太空總署開發的太空探測器，是一對一模一樣的探測器，分別會在6月8日及25日發射，2004年1月會抵達火星。漫遊者一、二號都會降落火星表面，放出漫遊車研究火星的地形，尋找火星地下是否埋藏了水源。漫遊者號是繼火星探路者號登陸火星號後，會在火星上行走的漫遊車。

Caption:: The Mars Exploration Rovers are scheduled for launch on or near this coming June, when Mars and Earth are relatively close in their orbits. The landing craft are expected to touch down on Mars in January 2004 and deploy the robot rovers shortly thereafter. Rovers have the capability to crawl about 100 meters each day of their planned 90-day mission. The mission's scientific purpose is to seek out and inspect interesting rocks and terrain that could give clues to the past of Mars.

Credit:: NASA/JPL

Mars Express 火星特快號 (30/5/2003)
過多3日，即6月3日，一連串新的火星探索任務又再展開。一個月內，3艘探測船會發射前往火星，其中一艘就是今次介紹的火星特快號。若果（記住，是若果）沒有延遲發射的話，會在香港時間6月3日凌晨1時45分發射，12月就可以抵達火星。相比起以前的火星探測船要7至12個月不等的時間，火星特快號所需的時間算短，正是因為火星將會是5萬年內最接近地球。這艘探測船由歐洲太空總署開發，圖中的是電腦模擬火星特快號在火星軌道上情況。

Caption:: On June 3, a new series of Mars exploration programs will be opened. Within one month, 3 spacecraft will be sent to space heading for Mars, in which one of these is Mars Express. If everything's alright, Mars Express will be launched at 01:45, Jun 3, and it will arrive the destination on Dec. Comparing with the previous missions to Mars, who spent 7-12 months for traveling, Mars Express is very fast as Mars will be closest to Earth within this 50000 years. Mars Express is operated by European Space Agency, the image shown here is the artist concept of the spacecraft over Mars orbit.

Credit:: NASA/JPL