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火星ウォッチ:赤い惑星は今どこだ?/ 軍神(火星)はあなたを殺さない [SPACE.com]
投稿者 ファントムランチ 日時 2003 年 8 月 25 日 23:28:21:oswAM6lqBSCW6



■Mars Watch: Where is the Red Planet Now?

On Aug. 27, 2003, Mars will be less than 34.65 million miles (55.76 million kilometers) away -- closer to our planet than it’s been in nearly 60,000 years. The view will be stupendous. Track Mars’ growing brightness with SPACE.com's exclusive Mars viewing maps and charts.[August Preview Story]
2003年8月27日、火星は3465万マイル(5576万キロメートル)の距離にまで接近する。 -- 約6万年ぶりの大接近である。

◆Finding the Red Planet:

The Roman God of War looms ever nearer, brighter, and more imposing during July as it approaches its historic rendezvous with Earth.

Mars is now easy to find [Maps http://www.space.com/spacewatch/where_is_mars.html]. The planet usually appears red or orangish, though sometimes -- depending conditions in Earth's atmosphere -- it can look yellowish.
火星を見つけることは今では容易である。この惑星は通常、赤かオレンジ気味の色で現れる。ときには -- 地球の大気の状態によって -- それは黄色がかって見えることもある。

Whatever, it is the unmistakable beacon of the pre-dawn southern sky and is now visible before midnight, too, for observers with a clear view of the horizon. Try looking after 10 p.m., or start earlier and watch Mars rise in the southeast. [Timetables]

◆How bright is Mars now?

Mars begins August shining at magnitude -2.3. On this astronomers・scale, larger numbers mean dimmer objects. Negative numbers are reserved for the brightest objects.

Except for Venus (which can be magnitude -4.0 and brighter) no other planet or star can be brighter than Mars is now. Come late August, Mars will glimmer at magnitude -2.9.

Mars' disk in a telescope expands during August-- affording an ever-better view to observers who have been trying to discern its surface features. Pre-dawn observations are best for this purpose, because Mars gains altitude steadily until dawn, and so then its light cuts through less atmosphere and arrives less distorted. [August Preview Story]
望遠鏡中の火星の表面も8月中にはかなり拡大して見えるだろう -- その表面の特徴を識別しようとしてきた観測者たちに絶好の視界を与えるはずだ。

Pre-dawn observations are best for this purpose, because Mars gains altitude steadily until dawn, and so then its light cuts through less atmosphere and arrives less distorted. [August Preview Story]

Orbital Oddities: Why Mars will be So Close to Earth in August 21 January 2003
The Summer of Mars: What You'll See, How to Observe 13 June 2003
Mars Set for Brightest Appearance in History This Month 01 August 2003
See Mars a Mere 186 Light-Seconds Away 08 August 2003
Magical Night Sky Week: Mars, Full Moon and Shooting Stars
Mars Will Not Kill You 【次に訳出してある記事です】
Earth vs. Mars: The Two Planets Weigh In
Mars Fever at Full Pitch, Telescopes in Short Supply
Mars: The Solved and Unsolved Mysteries

2002年10月8日  +1.8等星  距離22570/36315(万マイル/万km)
2003年5月1日    0.0等星  距離9193/14792
2003年8月27日  −2.9等星  距離3467/5578




17 August 2003 09:46 pm ET

■Mars Will Not Kill You

By Robert Roy Britt,Senior Science Writer

≪Editor's Note:Each Monday, SPACE.com will explore a mysterious or little known corner of the cosmos to enlighten earthlings about how the universe really works. This is the debut installment of Mystery Monday.≫

On Aug. 27, Mars will be closer to Earth than in nearly 60,000 years. This "close approach," as it's being billed, has some folks worried about potential dangers here on our planet.

One SPACE.com reader asks: "Will it be dangerous when Mars gets that close to Earth? It has me a little worried." Others have e-mailed to say they heard there would be earthquakes or other disasters. One of the many rumors going around says the two planets will collide.

◆The true gravity of the situation is benign. There is absolutely nothing to worry about.

At its closest, Mars will still be nearly 34.65 million miles (55.76 million kilometers) away. The effectiveness of gravity is a function of mass and distance, so while the pull of an object is said to act across the cosmos, it does so with ever-diminishing effect. At great distances -- such as between Earth and the other planets -- the gravity of an object becomes little more than background noise, like the hum of a Cadillac from 20 blocks away amid the cacophony of a construction site in Midtown Manhattan.

Other readers say they heard Mars will look as big as the Moon. It will not. On Aug. 27, Mars will look pretty much like it looks now, shining as a very bright star-like point of light. With a telescope, of course, you can make it as big as your wallet allows.

◆Why the rumors?

Planetary doom prognostications pop up again and again because a handful of astrologers and self-anointed visionaries persist in disseminating garbage about how the positions of the planets can affect Earth by generating earthquakes, storms or other catastrophes. The Internet has made publishing of these false claims easy and more frequent.

"Only those who are foolish enough to think the motions of the planets have a bearing on their lives believe in this pseudo-science," says Joe Rao, SPACE.com's Night Sky columnist. He has been getting e-mail about this, too.

"There will be those who will try and convince the masses that this close approach will mean terrible cataclysms and catastrophes that will befall our planet," Rao said. "This close approach between Mars and Earth will have no effect on any other celestial bodies in space, including the Earth itself."

Forecasts of calamity typically precede alignments of several planets, as when three or more of the worlds inside Neptune gather approximately along a line in space so that, from Earth, we can see them bunched up in the night sky.

Groupings like this occurred in 2000 and again in 2002. Earth did not crumble.

Nothing unusual happened during other planet alignments through recorded history, either, and nothing unusual will happen on Aug. 27, except, of course, a whole lot of people around the world will step outside to look up at a cosmically historic event.

On that date, Mars will be slightly closer than ever in human history. The proximity owes to a regular occurrence of the two planets being on the same side of the Sun and the rare chance that Earth is about as far from the Sun as it ever gets just as Mars is about as close as it ever gets. (The two planets' orbits are not quite circular). In astronomers' parlance, Mars will be at opposition.

Mars has been almost this close during previous oppositions. In fact, the extra closeness this time is less than 1 percent compared to a similar setup in 1971.

Mars will shine brightly. It will look great in a telescope. It will not kill you.

◆The numbers

The gravity of Mars or any planet, given its relative small size and great distance from our own, is simply inconsequential.

The Sun and Moon do all the significant tugging around here. And these are real effects, stabilizing Earth's rotation, creating tides in the ocean, and even causing the rock-hard crust of the planet to rise and fall daily.

The Moon, though fairly small, is responsible for about two-thirds of tides because it is just 238,900 miles (384,402 kilometers) from Earth, on average. The much larger Sun -- even though it's about 93 million miles (150 million kilometers) away -- contributes the rest. For the record, the Sun makes up more than 99.8 percent of the entire mass of the solar system.
月はかなり小さいながらも、地球からたった23万8900マイル(38万4402キロメートル)しか離れていないので、潮の干満に関しておよそ3分の2の原因となっている。格段に大きなは太陽は、 -- それが約9300万マイル(1億5000万キロメートル)離れているので -- その残り【3分の1】に寄与している。本当のところ太陽の重力は、太陽系全体の99.8%以上を構成している。

The combined gravity of all the planets, even if lined up and all as close as possible to Earth at one moment, just doesn't matter to Earth at all compared to the Sun and Moon, according to NASA scientists.

Still the rumors are rampant. One reader asked Joe Rao if Mars will hit Earth.

"The odds that Mars will crash into the Earth on Aug. 27 are about as good as the Detroit Tigers winning the 2003 World Series in 4 games."

As of this writing, the Tigers were in the cellar of the Americal League Central Division with, by far, the worst record in baseball. And Rao is joking, of course. The Tigers have a much better chance of soaring to mythical heights than Mars has of fulfilling any of the silly mystic forecasts you might hear.

◆Tidal effects on Earth from the large bodies of the solar system,
with the Sun's effect ranked as 1.

  月 2.21
 太陽 1.00
 金星 0.000113
 木星 0.0000131
 火星 0.0000023
 水星 0.0000007
 土星 0.0000005
天王星 0.000000001
海王星 0.000000002
冥王星 0.0000000000001







つるちゃんのプラネタリウム 3D太陽系

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