HUJAN METEOR

TENTANG SAYA

NAMA : MANISHA BINTI HARUN

KOS : SARJANA MUDA PENDIDIKAN (KEPUJIAN)
FIZIK, UiTM PUNCAK ALAM, SELANGOR

Assalamualaikum dan salam sejahtera semua. Selamat datang! Anda pasti tertanya-tanya apa sebenarnya hujan meteor, bukan? Jangan risau, anda akan belajar banyak informasi dan ilmu pengetahuan baru dalam bahagian ini.

DEFINISI

METEOROID : Biasanya disebut sebagai "batu angkasa" ialah zarah angkasa yang bersaiz daripada butiran debu hingga asteroid yang lebih besar. Majoritinya adalah ketulan badan yang lebih besar yang telah hancur atau diterbangkan. Ada yang datang dari komet, asteroid, Bulan dan planet lain, namun kebanyakkannya datang daripada komet. Sesetengah meteoroid adalah berbatu, manakala yang lain adalah logam atau mempunyai campuran kedua-duanya.

METEOR : Meteor ialah meteroid yang menghasilkan bola api atau "bintang jatuh" yang memasuki atmosfera Bumi pada kadar kelajuan yang luar biasa dan terbakar. Bintang jatuh atau lebih dikenali sebagai tahi bintang ini berkemungkinan boleh dilihat pada mana-mana malam tertentu mengikut keadaan cuaca dan beberapa faktor lain.

METEORIT : Meteorit terbentuk apabila meteoroid bertahan dalam perjalanannya melalui atmosfera dan mendarat di atas tanah. Daripada keseluruhan meteor yang melintasi Bumi, kurang daripada 5% yang berkemungkinan akan jatuh ke bumi, saiznya dianggarkan antara serpihan kerikil atau sebesar penumbuk sahaja. Meteorit sangat susah untuk ditemui kerana kebanyakkan hujan meteor berlaku disebabkan oleh komet yang bahannya adalah sangat rapuh dan tidak mampu bertahan sepanjang melintasi atmosfera Bumi.

APA ITU HUJAN METEOR DAN BAGAIMANA IA TERJADI?

Secara umumnya, hujan meteor muncul dan memancar dari kawasan buruj pada waktu malam. Hujan meteor adalah satu fenomena yang berlaku apabila kita dapat menyaksikan meteor atau bintang jatuh (shooting star) memasuki atmosfera Bumi pada kadar kelajuan yang luar biasa dalam jumlah yang sangat banyak pada satu-satu masa.

Fenomena ini boleh terjadi apabila berlakunya lintasan antara orbit komet (orbit yang sangat bujur mengelilingi Matahari) dengan orbit bumi. Apabila orbit komet mendekati Matahari, ia akan menjadi terlalu panas dan sebahagian daripadanya akan mengewap. Sepanjang ia mengelilingi Matahari, terdapat banyak serpihan kecil daripada komet tersebut (ekor debu) tertinggal sepanjang laluan tersebut.

Apabila orbit komet melintas dekat dengan bumi, ia menyebabkan adanya tekanan ke atas meteoroid sehingga meteoroid kehilangan daya untuk mempertahankan kedudukan tetap di orbitnya sendiri dan memasuki atmosfera Bumi. Kebanyakan hujan meteor ini boleh diramal dan berlaku pada masa yang sama setiap tahun. Setiap jam, puluhan hingga ratusan meteor boleh dilihat semasa hujan meteor.

TYPES OF METEOR SHOWER

There is a very long list of the types of meteor shower that exist, but below are the list of some usual, famous and biggest meteor showers based on the date according to NASA Solar System Exploration. They were declared as the biggest and the best annual phenomenon. The constellation for which a meteor shower is named is simply used to help viewers to figure out which shower they're watching on any given night. The meteors do not come from the constellation; they can be seen everywhere across the night sky.

Kathie O’Donnell in Rapid City, South Dakota, USA, caught this meteor (below) and the International Space Station (above) on January 3, the peak morning of 2021’s Quadrantid meteor shower, despite a bright waning gibbous moon in the sky from 4 a.m. (MT) to 6:30 a.m.
Credit : EarthSky Communication Inc.

1.QUADRANTIDS

Quadrantids was inspired by the constellation Quadrans Muralis (it no longer exists) also called Boötes. It originated from an asteroid which is asteroid 2003 EH1 also known as “rock comet”. This constellation is located near the end of the handle of the “Big Dipper”.

This is the first major meteor shower which is expected to appear most actively from the end of December through the second week of January, reaching a peak around the first week of January. It is expected to peak in only a few hours.

The average rate of this meteor shower is approximately 80 meteors per hour and it travels 41 kilometers per second.

Composite image of Lyrid and not-Lyrid meteors over New Mexico from April 2012. Image via NASA/ MSFC/ Danielle Moser.
Credit : EarthSky Communication Inc.

2. LYRIDS

Lyrids was inspired by Lyra, the harp constellation. It originated from a comet which is C/1861 G1 Thatcher. Lyrids seem to radiate forth from the star Vega which is the brightest star in this constellation.

This is the second major meteor shower which is expected to appear most actively on April 16-25, reaching a peak approximately around April 22. It is expected to peak overnight and usually it will start about 10:30PM until before dawn.

The average rate of this meteor shower is approximately 100 meteors per hour and it travels 49 kilometers per second.

Early Eta Aquariid meteor, caught by Eliot Herman in Tucson, Arizona on May 1, 2021.
Credit : EarthSky Communication Inc.

3. ETA AQUARIDS

Eta Aquarids was inspired by Aquarius, the water bearer constellation. It originated from a comet which is 1P Halley. This shower was radiated from the Eta Aquarii which is one of the brightest stars and made up to the top of the “water jar”.

This is the third major meteor shower which is expected to appear most actively on April 19 - May 28, reaching a peak before dawn May 6. It is expected to peak for several days before dawn on May 6.

The average rate of this meteor shower is approximately about 10-20 meteors per hour. This shower is well-known for its fast speed which is 66 kilometers per second.

David S. Brown caught this meteor in late July 2014, in southwest Wyoming.
Credit : EarthSky Communication Inc.

4. DELTA AQUARIDS

Delta Aquariids was inspired by Aquarius, the water bearer constellation. This shower was suspected to originate from comet 96P/Machholz. It was radiated from Delta which is the third brightest star in this constellation.

This is the forth major meteor shower which is expected to appear most actively on July 12 until August 23, reaching a peak on or near July 29. It is also expected to peak for several days before and after July 29.

The average rate of this meteor shower is approximately 20 meters per hour and it travels 41 kilometers per second. It is difficult to spot this shower but it will radiate in the southern part of the sky.

Composite of 12 images acquired on August 13, 2017, by Felix Zai in Toronto. It’s only in a meteor “storm” that you’d see this many meteors at once. Even in a rich shower, you typically see only 1 or 2 meteors at a time.
Credit : EarthSky Communication Inc.

5. PERSEIDS

Perseids was inspired by Perseus, the hero constellation. It originated from a comet which is 109P/Swift-Tuttle. This shower was radiated near the famous Double Cluster which consists of two open star clusters and quite near to Cassiopeia, the queen constellation.

This is the fifth major meteor shower and also the most popular meteor shower of the year which is expected to appear most actively on July 14 until August 24, reaching a peak on August 11-13. It is expected to peak for several days.

The average rate of this meteor shower is approximately 50 to 100 meteors per hour. It travels at a very fast speed which is 59 kilometers per second.

Randy Fullerton in Sardis, Mississippi, USA, caught this meteor on October 26, 2021.
Credit : EarthSky Communication Inc.

6. ORIONIDS

Orionids was inspired by the famous constellation Orion, the hunter. It originated from a comet which is 1P/Halley. This shower was radiated from the north of star Betelgeuse which is a bright star in Orion.

This is the sixth major meteor shower which is expected to appear most actively on October 2 until November 7, reaching a peak approximately around October 20. It is expected to peak overnight and be best visible around 2 AM.

The average rate of this meteor shower is approximately 15 meteors per hour. This shower travels at very fast speeds which is 66 kilometers per second.

Eliot Herman captured this double Leonid meteor, 2 days before the peak of the shower in 2018 in Tucson, Arizona.
Credit : EarthSky Communication Inc.

7. LEONIDS

Leonids was inspired by Leo, the lion constellation. It originated from a comet which is 55P/Tempel-Tuttle. This shower was radiated near the star Algieba in the Leo constellation .

This is the seventh major meteor shower which is expected to appear most actively on November 6 until November 30, reaching a peak approximately on November 16-17. It is expected to peak overnight on that date and it can peak with hundreds to thousands of meteors per hour.

The average rate of this meteor shower is approximately 15 meteors per hour. This shower is considered as one of the fastest meteor showers which travels at 71 kilometers per second.

Kent and Carolyn Carlson captured this meteor over Moraine Park, Rocky Mountain National Park, Colorado, on December 13, 2020.
Credit : EarthSky Communication Inc.

8. GEMINIDS

Geminids was inspired by Gemini, the twins constellation. It originated from an asteroid which is 3200 Phaethon also known as “rock comet” or “dead comet”. This shower was radiated near the bright star Castor in the Gemini constellation.

This is the eight major meteor shower which is expected to appear most actively on December 4 until December 17, reaching a peak approximately on December 13-14. It is expected to peak overnight and be best visible around 2 AM.

The average rate of this meteor shower is approximately 120 meteors per hour and it travels 35 kilometers per second.

ADAKAH METEOROID ATAU ASTEROID
BOLEH MENGHENTAM BUMI?

Menurut Dr. Kelly Fast (Pengurus Pejabat Penyelarasan Pertahanan Planet NASA), asteroid boleh menghentam bumi malahan sudah ada sejarahnya dan berkemungkinan akan terjadi di masa hadapan.

Meteoroid, asteroid kecil dan serpihan habuk telah menghentam Bumi sepanjang masa. Kejadian ini menghasilkan bintang jatuh apabila ia memasuki atmosfera Bumi. Namun, kesan asteroid yang menjejaskan permukaan adalah lebih jarang berlaku dan boleh berlaku dalam masa ratusan, ribuan malah jutaan tahun.

Berita baiknya ialah asteroid yang lebih besar yang boleh mendatangkan bahaya kepada Bumi lebih mudah ditemui dan hanya ada sedikit sahaja daripada asteroid tersebut berada dalam sistem suria. Penemuan ini adalah sangat penting untuk memberi amaran serta persediaan awal untuk mengurangkan impak pada masa hadapan sekiranya ia ditemui.

METEORIT YANG
DIJUMPAI DI BUMI

ADAKAH METEOR BOLEH MENDARAT DI BUMI?

Boleh! Meteor yang mendarat di Bumi dikenali sebagai Meteorit.

Lebih daripada 50,000 meteorit telah ditemui di Bumi. Daripada jumlah ini, 99.8% datang daripada asteroid. Pecahan kecil yang selebihnya (0.2 peratus) dibahagikan kira-kira samada antara meteorit dari Marikh dan Bulan.

Pada zaman dahulu, Bumi telah mengalami banyak kesan meteor besar yang menyebabkan kemusnahan yang meluas. Kebanyakkan kesan kawah di zaman purba telah dipadamkan oleh hakisan dan proses geologi lain, kawah Bulan sebahagian besarnya masih utuh dan kelihatan. Hari ini, kira-kira 190 kesan kawah ada di Bumi.

Ahli astronomi NASA Peter Jenniskens dengan meteorit asteroid yang ditemui di Gurun Nubia di utara Sudan. Kredit: NASA/SETI/P. Jenniskens

Walaupun sukar untuk menemui meteorit, namun sudah ada meteorit yang berjaya dikesan dan direkodkan.

Meteorit di bawah adalah salah satu meteorit yang dijumpai di Bumi dan merupakan meteorit terbesar di Dunia.

Gambar Meteorit Hoba yang diambil oleh Giraud Patrick pada 13 Ogos 2006.

1. HOBA - METEORIT TERBESAR DI DUNIA

Meteorit besi (iron-meteorite) seberat 66 tan telah ditemui oleh seorang petani di Grootfontein, Namibia. Meteorit ini dinamakan "Hoba" berasal daripada ladang bernama Hoba West. Hoba adalah meteorit tunggal terbesar dan kepingan besi terbesar yang pernah ditemui. Hoba berukuran kira-kira 9 kaki panjang, 9 kaki lebar dan 3 kaki tebal.

Hoba dipercayai telah jatuh ke Bumi kira-kira 80,000 tahun dahulu, terdiri daripada kira-kira 84% besi, 16% nikel dan kesan kobalt serta logam lain. Pengkaji juga mempercayai bahawa Hoba lebih besar daripada itu kerana terdapat banyak oksida besi di dalam tanah di sekelilingnya, menunjukkan ia telah mengalami kekurangan yang ketara akibat pengoksidaan.

FREQUENTLY ASK
QUESTION

WHAT CAUSES OF A METEOR SHOWER?
The Earth passes through debris left behind by a comet's course. These particles vaporise high in the Earth's atmosphere, producing a lovely luminous glow.
DOES METEOR SHOWERS OCCUR ONLY ON EARTH?
Any other solar system body with an adequately clear atmosphere can host meteor showers. The Spirit Mars rover captured a streak in Mars' sky. It was most likely a meteor from the Martian meteor shower.
WHAT ARE METEOR SHOWERS NAMED AFTER?
The showers was named from the constellation from which they appear to be falling. It is simply used to help viewers to figure out which shower they're watching on any given night.
WHAT ID RADIANT?
The radiant is the spot in the sky where all the meteors appear to be originating. A meteor could appear anywhere in the sky to an observer. However, tracing the direction of motion backwards will reveal the radiant.
WHAT IS METEOR STORM?
Meteor storm is called when a meteor shower has a frequency of at least one meteor per second. In order for a meteor shower to be classified as a meteor storm, the rate of the shower must reach 1000 per hour (or 1 per second).
WHAT IS METEOR OUTBURST?
Meteor outburst is the common name for random meteor storms which is not an annual meteor showers. Rates will only exceed the typical level of annual activity when the Earth passes through relatively new cometary debris. Then, and only then, will we witness a meteor outburst.
WHAT IS THE NAME OF METALLIC EMISSION GLOW IN THE PATH OF BRIGHT FIREBALLS?
Afterglow. It only lasts for a few seconds.