オリオン座流星群は、10月21日の夜にピークを迎える。夜23時過ぎから翌日の明け方までオリオン座あたりを中心に四方八方で見られるという。2006年以降、オリオン座は活動が活発な状態が続いている。tenki.jpが報じた。

観察時間帯は23時頃から明日の明け方。一昨日に満月だったため、今夜は月明かりが強い。なるべく月が視界に入らず&市街地でない方向の空を広く見渡して眺めて下さい。

(日本気象協会 tenki.jp「秋の夜長、オリオン座流星群の観察はいかが(日直予報士) 」より 2013/10/21 10:25)

国立天文台によれば、オリオン座はハレー彗星を起源とする流星群。オリオン座流星群の特徴は、スピードが早く明るい流星が多いことだという。

21日朝10時の時点での全国の観測予報は以下となっている。東海から西の太平洋側は流星が観測しやすいようだ。

北日本や山陰地方は低気圧や湿った空気の影響が残るため雲が多く、流星観測は雲に邪魔をされてしまいそうです。また、関東など東日本や沖縄でも雲が広がりやすくなるため、雲の隙間を狙っての流星観測となりそうです。一方で東海から西の太平洋側は、大陸からのカラッとした空気に覆われて雲が少なく流星観測には好条件です。

(ウェザーニュース ニュースリリース「オリオン座流星群が今夜ピーク!22時より「SOLiVE24」で全国7カ所から生中継」より 2013/10/21)

夜になると気温は下がる。内陸部や山沿いではグッと冷え込むという。オリオン座流星群を眺める場合は、暖かい服装で観察するといいだろう。

※オリオン座流星群を見てみたいですか? あなたの意見をお聞かせください。

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    <a href="http://www.huffingtonpost.com/social/Elder_One"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/Elder_One">Elder One</a>:<br />Taken with 10" Newtonian in central BC, Canada

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    <a href="http://www.huffingtonpost.com/social/Elyas_Fraenkel_Isaacs"><img style="float:left;padding-right:6px !important;" src="http://graph.facebook.com/100000506109606/picture?type=square" /></a><a href="http://www.huffingtonpost.com/social/Elyas_Fraenkel_Isaacs">Elyas Fraenkel Isaacs</a>:<br />Gravitational density causes rotation. The resultant forces create matter streams which eventually coalesce to stellar bodies.

  • Venusian Transit, 6-5-12, Sunset

    <a href="http://www.huffingtonpost.com/social/sw33tman"><img style="float:left;padding-right:6px !important;" src="http://images.huffingtonpost.com/aol_profile_img/1698758.png" /></a><a href="http://www.huffingtonpost.com/social/sw33tman">sw33tman</a>:<br />Photo by Marty Swinney. 800mm (35mm equivalent 400mm), 1/6000 @ f22