Mars the size of the moon!

  • Thread starter Gale
  • Start date
639
2
So, i was on vacation and watching the New Tom Green Show, (which is much better than the old one imho) and this absolutely hilarious theoretical physicist guy was on and he was talking about how on the 27th of this month that Mars will be closest to the earth than it's been in... i forget how long, but it was a lot of years. He said it would be like as bright as the moon!! Then he started talking about life on Mars and a lot of other stuff which made me unsure about his credibility.

Anyways, anyone who knows about this Mars thing fill me in if you would. It'd be a site to see i'm sure.
 

Janus

Staff Emeritus
Science Advisor
Insights Author
Gold Member
3,393
1,066
While it is true that on the 27th, Earth and Mars will be closer to each other than they have been for several thousand years, It isn't that much of a difference from any other close opposition (Which occur at about 15 year intervals)

At that time, Mars will have a visual magnitude of -2.88. The more negative the magnitude, the brighter the object. On that night, the Moon will have a magnitude of -5.06, which on the magnitude scale means it will be about 3 1/2 times brighter that Mars. But this is only because the Moon will not be near a full moon on that night.

A full moon has a magnitude of -12.5 or so, making it about 6000 times brighter than Mars will be at its closest.
 

russ_watters

Mentor
18,833
5,019
Originally posted by Gale17
He said it would be like as bright as the moon!! Then he started talking about life on Mars and a lot of other stuff which made me unsure about his credibility.
This (common) misconception comes from misreading an AP story that says (correctly) when viewed under 75x MAGNIFICATION THROUGH A TELESCOPE, Mars will appear as large as the Moon TO THE NAKED EYE.

Further discussion http://www.badastronomy.com/phpBB/viewtopic.php?t=7410 [Broken]

Also, though Mars will be its closest in about 60,000 years, it is not substantailly closer than it comes every 2.5 years. It only varies by a few percent and in 1971 it was less than 1% further than it is now - close enough that the difference would barely have been noticeable through the Hubble Space Telescope (the highest resolution telescope we have). This and other misconceptions/media overhype discussed HERE
Its a neat thing and I'll have my telescope out as soon as the damn weather clears up, but its nothing Earthshattering.
 
Last edited by a moderator:
91
0
Originally posted by Janus
While it is true that on the 27th, Earth and Mars will be closer to each other than they have been for several thousand years, It isn't that much of a difference from any other close opposition (Which occur at about 15 year intervals)

At that time, Mars will have a visual magnitude of -2.88. The more negative the magnitude, the brighter the object. On that night, the Moon will have a magnitude of -5.06, which on the magnitude scale means it will be about 3 1/2 times brighter that Mars. But this is only because the Moon will not be near a full moon on that night.

A full moon has a magnitude of -12.5 or so, making it about 6000 times brighter than Mars will be at its closest.
isn't the 27th a new moon???
 

Janus

Staff Emeritus
Science Advisor
Insights Author
Gold Member
3,393
1,066
Originally posted by kleinma
isn't the 27th a new moon???
Yes, but even on the Night of a new moon, the Moon will reflect some light.

For instance, at 12:00 am on the 27th, the moon will have the Magnitude listed and about .9 percent of its sun lit face will be visible. This will cause it to be about 3.5 time brighter than Mars at that time.
 

Labguy

Science Advisor
729
7
Originally posted by Janus
Yes, but even on the Night of a new moon, the Moon will reflect some light.

For instance, at 12:00 am on the 27th, the moon will have the Magnitude listed and about .9 percent of its sun lit face will be visible. This will cause it to be about 3.5 time brighter than Mars at that time.
True, true. But, the moon will be setting "with" the sun and will be totally out of the way to distract, with any light problem, from a view of Mars or anything else we want to view at that night.
 

Janus

Staff Emeritus
Science Advisor
Insights Author
Gold Member
3,393
1,066
Originally posted by Labguy
True, true. But, the moon will be setting "with" the sun and will be totally out of the way to distract, with any light problem, from a view of Mars or anything else we want to view at that night.
My remarks were aimed at the original comment that Mars would be as bright as the Moon.
 

Labguy

Science Advisor
729
7
Originally posted by Janus
My remarks were aimed at the original comment that Mars would be as bright as the Moon.
Oh, I know that, it was obvious and accurate. I was only trying to point out to any "first-timers" that the moonlight would not "compete" with any view of Mars.
 

Phobos

Staff Emeritus
Science Advisor
Gold Member
1,927
6
I'm sure Tom Green has a rigorous screening process for the scientific credibility of his guests. :wink:

So, how many "Uranus" jokes did he make?

Welcome to PF, Gale17! Always good to have another Granite Stater around. :smile:
 
639
2
I'm sure Tom Green has a rigorous screening process for the scientific credibility of his guests.


So, how many "Uranus" jokes did he make?

Welcome to PF, Gale17! Always good to have another Granite Stater around.
haha, i know, the guy started talking about weird things and showed those really old pictures of that face on mars. he didn't seem all there. tom green just liked him cause he looked funny and talked crazy. and your right about the uranus jokes, once the old guy started talking about mars all tom would say is tell me about uranus, or he'd touch the model solar system and be like, woo i'm touching uranus. it was pretty funny, but yeah, i got my hopes up thinking that mars would be huge. ah well, it was entertaining.
 

Related Threads for: Mars the size of the moon!

Replies
4
Views
813
  • Posted
Replies
2
Views
2K
  • Posted
Replies
2
Views
8K
  • Posted
Replies
1
Views
2K
Replies
28
Views
1K
  • Posted
Replies
7
Views
3K
Replies
817
Views
46K
Replies
4
Views
3K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top