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masih belum ada idea :-)

24.5.09

The Often Neglected Star - Our Sun

An introduction....

Astronomers spend their lives looking at the stars, but all too aften the nearest star is neglected, the Sun.

The Sun is the very heart of the Solar System. Its light and heat enables life to exist on our planet. The Sun itself is physically enormous, spanning some 1.39 million kilometres in diameter (over 100 times greater than the Earth). Nevertheless, compared to other stars in our galaxy the Sun is relatively small and unremarkable. It lies on average 149.6 million kilometres from Earth and spans about 0.5 degrees in angular diameter as seen from our planet. As the Sun is gaseous its rotation period varies with latitude, with the equitorial region moving faster than at the poles. The average rotation period is 27.25 days.

The Sun shows a well defined cycle of activity that is referred to as the solar cycle. It was a German farther and son team of David and Johannes Fabricius who first published observations of sunspots in June 1611, a year before Galileo's similar observations.

Continuos support records exist from 1849 onward, around the time that the pattern of the solar cycle was first noticed. The cycle is defines by the amount of active regions visible on the disc, the number of which wax and wane in a regular pattern over approximately an 11-year period. For a typical cycle, smaller spots appear at higher latitudes and, as activity increases, the spot activity migrates toward the equator and during the maximum activity of the cycle they generally concerntrate around 15 degrees north and south of the solar equator.

Magnetism is the key to all this solar activity. Active regions of spots, huge and intricate prominences, loops and streamers at the chromosphere and coronal mass ejections are all shaped and driven magnetically. The solar cycle itself results from the recycling of magnetic fields from the movement of the material in the interior of the sun.

22.5.09

The Fastest Moving Artificial Object In History - On A Journey To Pluto PART 3

Read part 1 here.
Read part 2 here.


The Jupiter encounter gave the New Horizons team a plethora of scientific news, but it also provided a valuable dress rehearsal for Pluto. New Horizons team members began filling in the details of the Pluto encounter shortly after the dust settled from the Jupiter fly-by. Programmers will leave gaps in the chain of commands that the spacecraft will use to execute its fly-by. The gaps can be filled in nearer to the Pluto encounter, as more data becomes available.



The challenges at Pluto are unique. Aside from the low light levels at Pluto's orbit, data rate will be reduced by the spacecraft's great distance from home. While light - and radio - time from Jupiter during the encounter was about an hour and half, light time at Pluto is up to four hours. The amount of data the spacecraft can transmit drops significantly.

Fly-by speed at Pluto will be comparable to the speed at which Voyager 2 flew by Triton, a moon that may be similar to Pluto in many ways. Voyager was only able to obtain a handful of medium resolution images of Triton. In contrast, New Horizons will take thousands of images, beginning at 200 days out. Early images will be equivalent in resolution to those taken by the Hubble Space Telescope. Each time the resolution doubles, a new set will be taken and transmitted to Earth. The last few days will see resolutions down to the size of a football field.

The spacecraft will image both Pluto and Charon, and will also scrutinize Nix and Hydra, the two small moons discovered in 2005. The craft will search for other moons and rings. In the case of Jupiter, the rings are fed by debris from its small moons.



In New Horizons' field of vies, Pluto will pass by 134 times as fast as Jupiter did. To avoid smearing of images, the spacecraft will have to slew, or turn, while imaging the planet and its moons. This slewing was utilized at Jupiter with great success. At Pluto, the camera must slew down by another factor of 50. The craft will carry out compositional and infrared studies, as it did for some of the icy satellites at Jupiter.

Pluto has a lot of colour variation and the greatest contrast of any body in the Solar System. Additionally, New Horizons will study Charon up close, making global maps in as much detail as Pluto. The astrophysicist will orient the spacecraft to point toward the Earth as it passes behind Pluto to study the atmosphere. It will then turn again to study Charon within the next hour.

Pluto is a member of a cloud of icy debris at the edge of our Solar System called the Kuiper Belt. After the Pluto mission, New Horizons is designed to fly past at least one other member of the Kuiper Belt. No target has yet been chosen as the area of study lies against a background of many stars and has, in the past, not been search extensively.

21.5.09

REHAT JAP - are you a GENIUS? test here

IF,

2+3=10

7+2=63

6+5=66

8+4=96

9+7=?????

19.5.09

The Fastest Moving Artificial Object In History - On A Journey To Pluto PART 2

Read Part 1 here

New Horizons is equipped with a suite of instruments called the Solar Wind Analyzer Around Pluto (SWAP), designed to chart fields of energy and charged particles in the interplanetary environment. Jupiter is surrounded by the largest and most complex magnetic bubble, or magnetosphere, of any planet. With the expectation of the sun, Jupiter's energy is the most powerful source in Earth's sky. In fact, to the naked eye viewed from Earth, Jupiter's magnetosphere would appear twice as far across as the full moon. The human eye cannot see such things, but New Horizons can and this was one of the most important aspects of the Jupiter encounter. The magnetosphere of Jupiter forms a titanic bubble of resistance against the storm of particles that flow constantly from the sun - the solar wind. Trailing behind the planet is the magnetotail, a sort of planetary wake cast by Jupiter across the Sun's magnetic fields.

A representation of Jupiter's magnetosphere and how it interacts with its moons, in particular lo. The lo Plasma Torus is a ring of charged particles emitted by lo's volcanoes that links the moon to Jupiter.
Image: John Spencer (Southwest Research Institute)


Like other New Horizons instruments, SWAP was designed for the subtler environment of Pluto, so its sensitivity had to be reduced in Jupiter's neighbourhood. New Horizons SWAP experiments are similar to equipment flown on earlier missions. The major advantage this time around was the flight path of New Horizons, as it is the first spacecraft to fly down the magnetotail. Additionally, the spacecraft passed through the magnetosphere in a different direction from earlier explorers, giving researchers an invaluable new slice of the complex system to study.

New Horizons confirmed some aspects of earlier theories and models of Jupiter's complicated fields and particles, but shed light on new aspect as well. There were a lot of subtle suprises in the details of how this things works.

One revelation has been how complex the magnetotail is, most models potray it as a column of quiet space - a kind of magnetic backwater - behind the planet. But New Horizons data shows that the region is complicated and interesting. The is no obvious, simple picture. The magnetotail is a highly structured planetary environment and it will take some time to figure it out.

At this moment of writing, New Horizons is continuing down the tail at a relative speed of 10-15 kilometres/second. The tail appears to move back and forth in the solar wind. At a distance of 2000 planetary radii (around 142 million kilometres), the spacecraft is still within the planet's wake.

To see an animation of New Horizons' voyage down the magnetotail, visit the New Horizons website here.

16.5.09

Pemanasan Global - Bumi Semakin Panas!!!

Fenomena pemanasan global semakin hangat dibincangkan. Protokol demi protokol dikeluarkan...bermacam resolusi terhasil di setiap persidangan antarabangsa anjuran badan-badan dunia, namun ia tetap saja tidak membuahkan hasil. Kuasa besar seperti Amerika Syarikat masih gagal mematuhi Protokol Kyoto dengan alasan ia akan memusnahkan ekonomi negara polis dunia itu.

Pemanasan global...apakah punca-puncanya?
Ramai yang beranggapan pemanasan global berlaku akibat pencemaran yang dilakukan manusia melalui pelepasan gas-gas berbahaya seperti klorin dan karbon monoksida ke udara. Gas-gas ini lantas bertindakbalas dengan lapisan ozon di atmosfera lalu menghakisnya. Lalu, lebih banyak cahaya matahari dapat menembusi bumi, dan bum bertambah panas. Ini pendapat tradisional yang cukup popular....dan ia memang betul, antara penyebab kenapa bumi semakin panas.

Namun, tahukah anda bahawa pencemaran (baca pelepas gas) yang dihasilkan oleh manusia (industri & fisiologi) sebenarnya hanya menyumbang sekitar 5% kepada pencemaran udara. Faktor pencemaran yang lebih besar ialah letusan gunung berapi, proses pereputan semulajadi bahan-bahan seperti daun, haiwan dan lain-lain ke dalam tanah, proses penyejatan air di laut dan pelbagai lagi. Kesemua ini membebaskan gas-gas merbahaya ke udara dalam kuantiti yang jauh lebih besar.

Faktor lain yang boleh dikaitkan kenapa bumi menjadi semakin panas adalah perihal aktiviti matahari yang akan mencapai tahap maksimumnya pada 2012 nanti. Ketika ini, banyak sekali letusan solar berlaku di permukaan matahari, disamping beberapa siri ribut magnetik kecil-kecilan yang direkodkan NASA dan ESA. Faktor ini mungkin tidak sepopular faktor pencemaran industri yang dilakukan manusia, kerana tidak ramai yang mengetahui kejadian ini.

Lapisan dalam kerak bumi yang semakin memanas juga adalah faktor yang dikatakan menjadi penyumbang tentang isu pemanasan global ini. Teras bumi dikatakan agak tidak stabil ketika ini disebabkan beberapa siri gempa bumi besar yang terjadi beberapa tahun kebelakangan ini. Ketidakstabilan ini juga berpunca daripada pengaruh "magnetic force" dan "pole shift" yang kini melanda bumi (atau bakal terjadi). Saintis masih mengkaji fenomena ini secara lebih dekat dan terperinci.

Ok. Tinggalkan sekejap hal-hal "tradisional" tentang pemanasan global ini. Cuba berfikir lebih jauh, dalam konteks bumi ini sendiri...kenapa ia menjadi lebih panas?

Beberapa siri kajian (pernah diterbitkan sebagai dokumentari beberapa tahun lepas - tapi bukan di stesen tv Malaysia) pernah dan sedang dilakukan oleh beberapa kumpulan saintis terkemuka dunia, di beberapa tempat di muka bumi ini. Data-data mengenai suhu bumi juga telah berjaya dikumpul dan dianalisa, dan hasilnya agak mengejutkan dan menjadi perdebatan hangat sedikit masa dulu.

Dalam tempoh-tempoh masa tertentu, permukaan bumi memang akan menjadi panas, sehingga ke suatu kemuncak sebelum ia mula kembali menyejuk. Hal ini pernah dicatatkan pada tahun-tahun 1930-an, 1963-1971 dan sekitar sebelum milenium. Pemanasan bumi berlaku dari unsur-unsur dari dalam bumi ini sendiri (teras bumi) sebelum kembali menyejuk. Terdapat segelintir saintis berteori bahawa ini sebenarnya adalah cara untuk bumi menstabilkan strukturnya dan adalah suatu hal yang tidak perlu dibimbangkan.

Fenomena yang berlaku ada tahun-tahun 1930-an menjadi bukti yang kuat bilamana suhu bumi meningkat secara mendadak untuk tempoh selama beberapa tahun sehingga mencapai titik puncak, sebelum secara berterusan mencatatkan penurunan global, sehingga mencetuskan ketakutan munculnya zamain ais baru pada waktu itu. Kebanyakan negara di Eropah dilitupi salji sepanjang tahun (negara berhampiran kutub seperti Norway, Denmark etc).

Adakah pemanasan yang berlaku kali ini juga sebegitu? yang mana bumi akan kembali menjadi sejuk secara beransur-ansur selepas mencapai kemuncak pemanasan dan terasnya kembali menjadi stabil? Ia sangat menarik untuk dibahaskan....

Walau apapun, jadilah seorang yang bertanggungjawab kepada bumi. Kurangkan penggunaan plastik, kimia dan amalkanlah kitar semula. Sedikit sumbangan anda amat besar jasanya untuk generasi yang akan datang.

13.5.09

The Fastest Moving Artificial Object In History - On A Journey To Pluto

New Horizons orbiting Jupiter

It's a long way out to Pluto. NASA's New Horizons spacecraft, the fastest-moving artificial object in history, will arrive there nine years after its launch, coasting by the distant world in the summer of 2015. But its speedy voyage would have taken four more years had it not been for a gravity slingshot afforded by Jupiter.

New Horizons' close fly-by past the king of worlds took place on 28 February 2007. The encounter served as far more than a practice run for the upcoming Pluto arrival. Jupiter is a prime candidate for planetary exploration, a window into the early solar nebula. Its weather patterns have lent insight into fluid dynamics, meteorology and theory. Its retinue of 63 moons - including the quartet of giant Galilean Satellites - provides a miniature solar system for study. Several of the Galilean are the size of planets and have surfaces of ice, as does Pluto and its moon Charon.

New Horizons' use of Jupiter's gravity to get to Pluto presented a valuable chance to study Jupiter in new ways. So far, seven spacecraft in total have visited Jupiter, but New Horizons is equipped with scientific instruments that have never before been flown close to the giant planet. In addition to imaging in visible wavelengths, the Pluto explorer can peer at objects in portions of the spectrum not revealed by earlier spacecraft. New Horizons was also able to take movies of phenomena that the earlier Galileo orbiter could not.

The New Horizons encounter was close than any previous fly-by. For example, New Horizons flew three to four times closer to Jupiter than Cassini did on its way to Saturn in 2000.

But, the encounter was not easy to pull off. The first year of flight was a busy one for the Pluto-bound robot. Engineers and scientists deployed and checked instruments. They made vital trajectory corrections to establish an accurate path for the long flight. They used various stars to calibrate the delicate sensors on the craft. In the midst of all the mayhem, scientists had to plan a complex, Jupiter fly-by only sketched out in preliminary plans.

Complicating the encounter was the fact that New Horizons' instruments were designed for a different environment. Sunlight at Jupiter is some 700 times as strong as that at Pluto. Instruments keyed to imaging in low light levels were prone to be overwhelmed by the bright Jovian environment. One strategy the team devised was to target the most important sights on Jupiter when they were at the terminator, the day/night boundary of the planet. Another significant difference between the Jupiter and Pluto encounters is the time available to the spacecraft during the two fly-bys.

Click here and here to read more about New Horizons' project.

10.5.09

Milky Way - Andromeda Collision



Our galaxy, Milky Way and its nearest large neighbor the Andromeda galaxy (M31), are on a collision course. Billions of years from now, the merger will transform the structures of both galaxies and creates a new arrangement of stars we have dubbed MILKOMEDA (Milky Way + Andromeda). The merger will radically transform the night sky.

Currently, the Milky Way's thin disk of stars and gas appears as a nebulous strip arching across the sky. As Andromeda grazes the Milky Way, a second strip of stars will join the one that presently graces the night sky in summer. After the final merger, the stars will no longer be confined to two narrow lanes, but instead, scattered across the entire sky.

In the research, Astrophysicist have explore the Milky Ways fate by simulating the Milkomeda's birth in a super computer. The simulations are at sufficient level of detail (resolution) to learn a lot about the coming merger and how it will change our perspective on the universe. Although we won't be here to witness the event, this is the first research on Earth that has a chance of being cited 5 billion years from now.


The Andromeda Galaxy
It is the largest galaxy among the local groups and a neighbor of Milky Way, located just next of Alpha Centauri, nearly 2.5 million light years away. Fourteen satellite galaxies accompany Andromeda, including the two visible on this image: M32 [above Andromeda] and NGC 205 [below Andromeda].


Evidence of the dynamic connection between the Milky Way and the Andromeda comes from their relative motions. The galaxies are barreling towards each other at nearly 270,000 mph (190,000 km per hours). This is because, the spectral lines of Andromeda's light appear to be blueshifted - displaced toward the blue end of the spectrum - by the Doppler effect. In contrast, most galaxies in the universe are flying away from the Milky Way.

Nearly 50 years ago, Franz Kahn and Lodewijk Woltjer pioneered the "timing argument". This hypothesis held that the Milky Way and Andromeda formed close to each other, during the dense in the early stages of the universe.

Subsequently, the general expansion of the universe pulled the two galactic neighbors apart. Later, the Milky Way and Andromeda reversed their out/vard trajectories owing to mutual gravitational attraction. Since then, they have completed nearly a full orbit around each other.

The timing argument, combined with estimates of the galaxies' relative velocities and other factors, indicates the local Group's total mass is about 3 trillion times the sun's mass. It also suggests the Milky Way and Andromeda will make a close pass in about 4 billion years.


FROM EARTH - we see the Milky Way from an insider's perspective. Depending in the time of year, an Earth-bound observer can see 3 or 4 different arms of the spiral.


CHANGE OF FORTUNE:
The Sun's peaceful orbit around the center of the Milky Way - which it has traverse nearly 20 times since it birth - will forever change. Its new path will be far more chaotic owing to the rapid fluctuations in gravity induced by the merger. What would this mean for Earth and its residents?

Research suggest that the Milky Way and Andromeda will begin to interact strongly 2 billion years from now, and then complete the merger in about 5 billion years. The latter date is especially notable because it coincides with the sun remaining life span. Currently, our sun is about halfway through its lifetime and eventually will begin to expand. As it does so, it will consumes all its available hydrogen and evolve toward a red giant phase within 5 billion years. In short, the sun will be in its death throes on Milkomeda's birthday.

Have You McValue LUNCH-ed This Week?

Anda penggemar hidangan lazat di McDonalds? Kini, anda boleh menikmati hidangan kegemaran anda setiap hari pada harga yang cukup istimewa!! Sukar untuk mempercayainya? Kunjungilah restoren McDonalds berhampiran anda, dan nikmatilah ia sekarang.

Dan...yang lebih sukar dipercayai, anda kini boleh memesan melalui telefon apa jua hidangan kegemaran anda. Tiada pesanan minimum dikenankan. Anda kini boleh menikmati tengah hari anda mengikut citarasa anda sendiri, dirumah atau dipejabat. Sungguh mudah!! Hanya dail 1300 13 1300, dan pesanan anda siap untuk penghantaran.


Apa yang ada tunggu lagi???
Nikmatilah hidangan kegemaran anda dengan gembira setiap hari, dimana jua anda berada. McDonalds tetap setia bersama anda.
Mana satu pilihan anda? Biar McDonalds hantarkan!!! 



 
Riang Ria di McDonalds. Dengan harga yang berpatutan, sesiapa saja boleh menikmati dengan penuh keriangan. Anda boleh saja menikmatinya sendiri dengan penuh ketenangan, atau bersama teman-teman yang pasti menyeronokan. Kunjungi McDonalds berhampiran anda dan beraksilah dengan gaya anda sendiri bersama hidangan kegemaran anda hari ini.


Semua sedang menunggu hidangan McValue lunch meal dengan penuh perasaan. Berjaya akhirnya hasut mereka semua untuk bersama menikmati hidangan Mcvalue lunch meal yang lazat dan menjimatkan. Menikmati McValue LUNCH meal bersama kawan-kawan memang sungguh mengasyikan (><)
HAVE YOU McVALUE LUNCH-ed MEAL THIS WEEK???





Klik sini untuk ke nuffnang-McDonalds contest


7.5.09

Solar System May Become Galactic Outcast


Our Solar System is destined to be sent flying towards the outer reaches of the galaxy when Andromeda galaxy collides with the Milky Way in a few billion years of time.

Recent calculations by theorists T J Cox and Avi Loeb (Harvard-Smithsonian Center for Astrophysics) suggest that huge gravitational forces that will grip the two galaxies will fling our Solar System four times farther out than its current position to a distance of 100,000 light years from the galactic centre.

The effects of the merger will start to be seen perhaps in as little as two billion years time. When it happens, the view of the night sky will dractically change from our current view. After five billion years, once the collision is over, the white band of Milky Way will disappear as the two galaxies merge and eventually our night sky will appear a mass of billions of stars.

Milky Way and Andromeda galaxy collision simulation picture
this collision is said to happen in 2 billion years of time



5.5.09

The Oldest Star In The Universe

Astronomers have found the oldest star ever seen in our own galaxy, a star that dates back a staggering 13.2 billion years, meaning that it formed just 500 million years after the big bang.

The relic star, known as HE 1523-0901, was observed at ultraviolet wavelengths by the European Southern Observatory's Very Large Telescope. It was discovered by Anna Frebel and her team. Analysing the light, they were able to measure the amount of key radioactive (thorium & uranium) elements in the star.

The dating method utilised by Frebel and her team required the measurement of unstable radioactive elements. This is because, the amounts of these elements found in the star depend very much on the time they have been around. As time goes by these elements decay, and by emasuring the abundances now astronomers can get an idea to how old the object is. The one caveat in the method is that there needs to be enough of that elements present for the astronomers on Earth to measure accurately.

Astronomers have been searching for the first generation of stars to come to a better understanding as to how stars formed in the first place. Most of this first generation has long since died out, but this ancient relic is a vital time capsule that will shed light on one of the earliest eras of the Universe.

An Amateur photograph of HE 1523-0901, the oldest star ever discovered
Image: Anthony Ayiomamitis

*notes....
  1. Astronomers determine the age of stars through the same concept used by archeologist on earth date a sample. The only different is, archeologist measures the carbon elements (carbon-14 dating technique) in their samples while astronomers measures radioactive elements (thorium & uranium) decay by stars.
  2. HE 1523-0901 is the 11th magnitude, 0.8-solar mass red giant ever discovered.
  3. HE 1523-0901 lies 7500 light years away from Earth, in the constellation of Libra.

4.5.09

Hujan Meteor - Allah Pencipta Hebat

Ramai sekali yang menganggap hujan meteor adalah hanya salah satu dari jutaan fenomena astronomi biasa yang berlaku saban waktu. Saat aku menulis ini, satu daripada berpuluh hujan meteor sedang berlaku. Hujan meteor Eta Aquarids, berlaku setiap tahun dengan kemuncaknya adalah pada 5 dan 6 May dimana sehingga 10 meteor dapat dilihat dalam masa sejam. Alhamdullilah, aku sempat menyaksikan satu meteor sebentar tadi. Aku juga berharap agar ramai lagi yang diberi kesempatan oleh Tuhan, untuk menyaksikan fenomena yang sungguh mengagumkan ini.


Jadi, apa hikmah berlakunya hujan meteor? Apa yang boleh dibuktikan disebalik kejadian "hujan" yang unik ini? Apa yang ada disebalik Lyrids, Geminids, Perseids, Quadrantids dan bermacam-macam jenis lagi hujan meteor??


Tentu ramai berkata...."alah, biasa saja tu. tiada apa-apalah. Tuhan yang menciptakan semuanya dan menjadi rahsiaNya. Kalau ada rezeki dapat la tengok, kalau tak pun takpe". Tapi, tidakkah kita berfikir bahawa setiap kejadian yang diciptakan Tuhan mempunyai hikmah disebalik setiap kejadian? Jadi, fenomena hujan meteor juga amat pasti mempunyai sebab yang tertentu, yang hanya boleh difikir dan dinilai oleh manusia yang mahu menggunakan akal yang dikurniakan oleh Maha Pencipta.


Disebalik hujan meteor sebenarnya ada satu rahsia yang besar, yang sangat mengkagumkan, dan yang sangat membuktikan bahawa Allah mencipta bumi ini istimewa untuk manusia-manusia yang menjadi khalifahNya. Bumi dibentuk sekian rupa agar manusia dapat hidup dengan selamat dan aman semasa hayatnya. Hujan meteor membuktikan kewujudan lapisan demi lapisan dalam atmosfera bumi, yang tidak kelihatan pada mata kasar. Troposfera, Stratosfera, Mesosfera, Termosfera dan Exosfera adalah lapisan pelindung bagi bumi, terhadap objek-objek dari angkasaraya.


Tahukah anda bahawa tanpa lapisan-lapisan ini, manusia tidak boleh hidup walau hanya untuk sesaat di muka bumi ini. Lapisan-lapisan inilah yang melindungi manusia dan segala makhluk Allah daripada bahaya ribuan, malah mungkin jutaan bahan-bahan radiasi dari matahari dan bermacam lagi objek di cakerawala (cosmic radiation). Lapisan-lapisan ini berfungsi memantulkan semula radiasi-radiasi berbahaya kembali ke angkasa, malah juga bertindak menyerap sebahagian daripadanya, seperti sinar ultra ungu yang dipancarkan oleh matahari. Lapisan-lapisan inilah juga yang membakar meteor dari angkasa yang memasuki bumi menjadi debu, agar is tidak memberi bahaya pada penghuninya


Semasa berlakunya hujan meteor, dengan jelas kita akan dapat melihat meteor-meteor (batu-batu kecil angkasa) ini terbakar saat ia sedang bergerak memasuki bumi, dengan kelajuan yang sangat tinggi. Meteor-meteor ini dibakar menjadi dedebu yang ditiup angin....Inilah bukti yang sangat nyata, bagaimana Allah menciptakan atmosfera sedemikian rupa untuk hamba-hambanya....dan bukti yang jelas bahawa lapisan-lapisan ini wujud, walau tidak kelihatan pada mata kasar manusia.


Mengkaji dan memahami fenomena astronomi mampu membuatkan kita semakin dekat dengan Allah.Segala yang dijadikanNya penuh dengan hikmah dan manfaat untuk manusia yang bijak menilai dengan akal dan hatinya.


Hujan meteor sedang berlaku saat fajar bakal menyising
Hanya beberapa meteor sahaja yang jelas kelihatan dengan mata kasar


Saksikan bagaimana meteor ini memasuki atmosfera bumi [A] dari angkasa. Ia bergerak dengan kadar kelajuan yang sangat tinggi. Dan, saksikan bagaimana atmosfera membakar meteor ini sehingga menjadi debu [B] dan ia kemudian berterbangan ditiup angin kesemua arah. Tidakkah anda mahu berfikir bahawa Allah itu pencipta yang hebat?

*Nota*
Pergerakan meteor memasuki bumi adalah dalam kelajuan yang sangat tinggi. Semasa melalui lapisan-lapisan dalam atmosfera bumi, meteor ini bergesel dengan molekul-molekul atmosfera dan geseran inilah yang membakar meteor berkenaan menjadi debu.


1.5.09

Bintang 3 generasi Ditemui

Penemuan terbaru "bintang 3 generasi" (Globular Cluster NGC 2808) oleh teleskop angkasa lepas Hubble telah berjaya merungkai satu lagi misteri cakerawala dan sekaligus menghapuskan teori bahawa bintang di dalam sesuatu sistem terbentuk pada tempoh waktu yang sama. Penemuan terkini ini juga telah menguatkan lagi bahawa cakerawala ini "hidup" dan sentiasa berkembang mengikut kadar yang belum diketahui manusia.

kumpulan Globular Cluster NGC 2808 yang berusia sekitar 12.5 billion tahun dan merupakan sistem kumpulan bintang terbesar di cakerawala

Image: NASA/ESA/A Sarajedini (Uni.Of Florida)/G Piotto (Uni.Of Padua)



Pakar-pakar astronomi, dengan bantuan Advance Camera for Surveys (ACS) yang terdapat pada teleskop Hubble, telah berjaya mengukur warna dan kecerahan bintang-bintang di dalam cluster berkenaan. Analisa yang dilakukan mendapati, siri bintang 3 generasi ini lahir sekitar 200 juta tahun lampau, dan terletak di dalam satu sistem besar yang berusia sekitar 12.5 billion tahun.

NGC 2808, dianggarkan mengandungi lebih sejuta bintang dan dikatakan antara sistem bintang yang terbesar di cakerawala yang berjaya dikenalpasti setakat ini.

Bagaimana sistem ini mempunyai 3 generasi bintang di dalam satu sistem yang sama?
Pakar-pakar astronomi berpendapat, kombinasi daya graviti antara jutaan bintang-bintang di dalam sistem ini adalah terlalu kuat, sehingga mampu "memegang" semua unsur-unsur gas (seperti helium yang terhasil daripada letusan-letusan bintang yang mati di dalam sistem ini sendiri) yang diperlukan utk kelahiran sebuah bintang baru.


3 Generasi bintang di Globular Cluster NGC 2808