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Joined: Aug 2003
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journeyman
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journeyman
Joined: Aug 2003
Posts: 95 |
A Martian year is almost twice as long as an Earth year. As the distance between Earth and Mars gets shorter, will our days grow longer, or their days shorter?
We haven't been this close to Mars since Sept. 12, 57617 B.C. Was Lucy walking upright then?
"Just 34.6 million miles of space will separate the two planets Aug. 27. If that doesn't sound close, Mars was five times as distant just six months ago.
Already, Mars has begun to loom large in the late evening sky, its rusty twinkle apparent in the southeast. For the next several weeks, it should shine brighter than any other celestial body except the moon and Venus.
Aldo Vitagliano, of the University of Naples in Italy, said Mars hasn't had as close a brush with Earth since Sept. 12, 57617 B.C."
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Joined: Jun 2002
Posts: 7,210
Carpal Tunnel
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Carpal Tunnel
Joined: Jun 2002
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Was Lucy walking upright then?Lucy had been dead for nearly three million years...  http://www.leakeyfoundation.org/discoveries/d2_1.jsplook at year 1974.
formerly known as etaoin...
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Carpal Tunnel
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Carpal Tunnel
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"A year on Mars lasts 687 Earth days and a Mars day at 25 hours is almost the same as an Earth day" Day length of a planet apparently is unrelated to its position in it orbit. I wonder what made day lengths so close on Mars and Earth. Here's a URL with a lot of data for all the planets: http://www.angelfire.com/moon/astronomy/planets.html
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Joined: Aug 2003
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journeyman
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journeyman
Joined: Aug 2003
Posts: 95 |
I wonder what made day lengths so close on Mars and Earth.
Good question, wwh. Haven't got a clue. But fact that length of day has no correspondence to the distance to the sun (which varies widely at perigee and apogee) is counter-intuitive to this astrophysically-challenged observer.
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Carpal Tunnel
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Carpal Tunnel
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day-length is dependent on the rotation of the planet, not the distance from the Sun. Earth and Mars are of a similar size and mass, therefore they rotate(spin) at nearly the same rate.
formerly known as etaoin...
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Carpal Tunnel
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Carpal Tunnel
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Is it Venus (another close cousin of Earth) that has a day longer than its year?
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Joined: Jul 2003
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Carpal Tunnel
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Carpal Tunnel
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Interestingly enough, snopes has this perspective to add: In reply to:
We should note that although Mars' close proximity to Earth in August 2003 will be a rare occurrence, the red planet comes almost as near to us every 15 to 17 years. To the unaided observer, Mars won't really appear significantly larger or clearer this August than it does at those intervals.
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Joined: Jun 2002
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Carpal Tunnel
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Carpal Tunnel
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after looking at Bill's great site, yes, it's Venus. really hot on one side...
formerly known as etaoin...
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Carpal Tunnel
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Carpal Tunnel
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That'as a great site, Dr. Bill, except for one little detail. They have used "Revolution period (length of year in Earth days)" when they should have used "Revolution period (length of year in Earth years)". Unless of course, Jupiter actually does take less than a fortnight to orbit Sol.
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Joined: Jun 2002
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Carpal Tunnel
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Carpal Tunnel
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and I just thought time was getting faster...
nice catch, Max. a tip of the slide-rule to ye.
formerly known as etaoin...
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