Mengap Terjadi hujan Meteor

Oleh: Muhamad Yusuf, ST

Tahukah anda, di saat anda terlelap malam tadi, bumi kita kejatuhan ribuan meteor? Fenomena itu sangat indah. Kilatan cahaya menghiasi langit malam, meluncur cepat ke Bumi

Bagi yang tak sempat menyaksikannya, tak usah menyesal, karena bulan depan akan ada fenomena serupa.

Peristiwa yang dikenal para astronom sebagai meteor shower itu merupakan gejala alam yang lumrah. Tak ada hal yang mistis yang melingkupi fenomena ini seperti dalam legenda-legenda kuno. Bahkan, imajinasi-imajinasi "heboh" ala Hollywood seperti meteor besar yang menghancurkan Bumi pun tidak terjadi. Sepanjang 18 - 23 Oktober 2008 memang menjadi momentum hujan meteor orionid.

Menurut Dr. Thomas Djamaluddin, Peneliti Bidang Matahri dan Lingkungan Antariksa, Lembaga Penerbangan dan Antariksa Nasional (LAPAN), hujan meteor kali ini merupakan peristiwa biasa. "Untuk kasus hujan meteor orionid bahkan terjadi dua kali setahun, yakni pada Mei dan Oktober," urai Thomas.

Hal yang sam juga diungkapkan Dr. Moedji Rahardjo, astronom dari Kelompok Keahlian Astronomi Institut Teknologi Bandung (ITB). Menurut dia, momentum hujan meteor sifatnya regular. "Ada pola-pola tertentu pada kemunculan hujan meteor. Hanya saja terkadang pola-pola itu tidak mudah dilihat," ungkapnya

Hujan Meteor memang tercatat telah berkali-kali terjadi dan diamati oleh banyak pihak. Bahkan, sebenarnya "serbuan" meteor ke Bumi berat totalnya dapat mencapai jumlah ribuan ton pertahunnya. "Dalam setahun, meteor yang masuk ke lapisan Bumi dapat mencapai 25 ribu ton. Jumlah itu termasuk hujan meteor yang terlihat dan tidak terlihat," ujar Thomas lagi.

Soal-soal Olimpiade Astronomi

Berikut ini kami sajikan soal seleksi olimpiade astronomi. Adapun contoh-contoh soal dari file yang bisa anda download adalah seperti dibawah ini:

1. Pada saat oposisi Bumi- Planet dan Matahari mendekati satu garis lurus, konfigurasinya adalah:

a. Planet – Bumi – Matahari

b. Bumi – Planet – Matahari

c. Planet – Matahari – Bumi

d. Matahari – Planet – Bumi

e. Tidak ada yang benar

2. Pada saat konjungsi Bumi-Planet dan Matahari mendekati satu garis lahir lurus, konfigurasinya adalah;

a. Planet – Bumi – Matahari

b. Bumi – Planet – Matahari

c. Planet – Matahari – Bumi

d. Matahari – Planet – Bumi

e. Tidak ada yang benar

3. Jika setengah sumbu panjang dan eksentrisitas planet Mars adalah a = 1,52 dan e = 0,09 sedangkan untuk Bumi a = 1 SA dan e = 0,017. Kecerlangan maksimum Mars pada saat oposisi, terjadi ketika jaraknya dari Bumi pada saat itu;

a. 0,37 SA

b. 0,27 SA

c. 0,32 SA

d. 0,40 SA

e. 0,50 SA

ESSAY:

2.) Sebuah asteroid ketika berada di perihelium menerima fluks dari mataharisebesar F0 ketika di aphelium ia menerima sebesar 0,5 F0. Orbit asteroidmempunyai setengah sumbu pendek b = 1,3 SA. Pertanyaannya;

a) berapakah periode asteroid ini

b) ketika di aphelium berapakah kecepatan lepas asteroid ini ?

Terdapat 2 file soal seleksi olimpiade astronomi, satu berbentuk Word Documentdan satu lagi dalam versi PDF.

Download soal olimpiade pada link dibawah ini:

» Download Link I (ziddu.com)

» Download Link II (myfilehost.us)

Kumpulan soal olimpiade astronomi ini bersumber dari 4shared.com

Melahirkan Ilmuwan Muda

A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method.^[1] The person may be an expert in one or more areas of science.^[2] This article focuses on the more restricted use of the word. Scientists perform research toward a more comprehensive understanding of nature, including physical, mathematical and social realms.

This is distinct from philosophers, those who use logic toward a more comprehensive understanding of intangible aspects of reality that lack a direct connection to nature, focusing on the realm of thought itself.

Scientists are also distinct from engineers, those who develop devices that serve practical purposes. When science is done with a goal toward practical utility, it is called 'applied science' (short of the creation of new devices that fall into the realm of engineering). When science is done with an inclusion of intangible aspects of reality it is called 'natural philosophy'.

Social roles that partly correspond with the modern scientist can be identified going back at least until 17th century natural philosophy, but the term scientist is much more recent. Until the late 19th or early 20th century, those who pursued science were called "natural philosophers" or "men of science".^[3][4][5][6]

English philosopher and historian of science William Whewell coined the term scientist in 1833, and it was first published in Whewell's anonymous 1834 review of Mary Somerville's On the Connexion of the Physical Sciences published in the Quarterly Review. Whewell's suggestion of the term was partly satirical, a response to changing conceptions of science itself in which natural knowledge was increasingly seen as distinct from other forms of knowledge. Whewell wrote of "an increasing proclivity of separation and dismemberment" in the sciences; while highly specific terms proliferated—chemist, mathematician, naturalist—the broad term "philosopher" was no longer satisfactory to group together those who pursued science, without the caveats of "natural" or "experimental" philosopher.

Members of theBritish Association for the Advancement of Science had been complaining about the lack of a good term at recent meetings, Whewell reported in his review; alluding to himself, he noted that "some ingenious gentleman proposed that, by analogy with artist, they might form [the word] scientist, and added that there could be no scruple in making free with this term since we already have such words as economist, and atheist—but this was not generally palatable".^[7]

Whewell proposed the word again more seriously (and not anonymously) in his 1840 The Philosophy of the Inductive Sciences:

We need very much a name to describe a cultivator of science in general. I should incline to call him a Scientist. Thus we might say, that as an Artist is a Musician, Painter, or Poet, a Scientist is a Mathematician, Physicist, or Naturalist.

He also proposed the term physicist at the same time, as a counterpart to the French word physicien. Neither term gained wide acceptance until decades later; scientist became a common term in the late 19th century in the United States and around the turn of the 20th century in Great Britain.^[8][9][10] By the twentieth century, the modern notion of science as a special brand of information about the world, practiced by a distinct group and pursued through a unique method, was essentially in place.

Sources:

1. Wikipedia

2. Google