black line across mars

[cushbag86]

While looking at Mars through my skywatcher refractor on sunday night I got a straight black line through the planet. When i took a look through my binoculars it was still there. It was only on Mars not the Moon or any other body. ?? Any one have any ideas. Thanks Cush

 

[beka]

Hi cushbag86, very hard to explain with the little detail you provided. I would take a little more time observing to see if the artifact is really there. The only thing I can think of that can explain this are floaters in your eye.

[theclearskiesofthemoon]

As Mars is fairly low on the horizon late at night, might it have been some sort of structure on the ground appearing in front of the planet?

[Owmuchonomy]

Cable maybe. You weren't looking at Saturn were you?

[John]

Were you using a 45 degree prism by any chance ?

[barkis]

Could have been a telephone line, or washing line in your light path,  hence it's disappearance  when you moved the scope to another target.
 

[Peter Drew]

Bar code?  

[Wardr77]

Depending on the quality of your optics it maybe a canal  

[Kropster]

Hair in the eyepiece?

[astro mick]

Could have been a Mars           Bar.

[ollypenrice]

Oh no, the canals are back! I'd have thought a foreground cable would be way too far out of focus to look line-like. A hair, maybe, or just an effect from your eye? Curious about John's diagonal question...

Olly

[Peter Drew]

Olly, the 45 degree diagonals contain a roof prism, the tip of the roof can form a line across the field.   

[LukeSkywatcher]

There is a thin black line across the mirrors in erecting prisms. I use one but have never noticed it when observing. I would have thought it was too close to the eye (focus point) to be noticed.

[beka]

cushbag86 said he saw the line through his telescope and binoculars, so we have to rule out factors due to the instruments. Mars in binoculars would be tiny so seeing a line "through" it is hard to imagine. cushbag86 - I think if you do more observation, you will find that maybe the findings you described in your post may not hold up.

[glowjet]

It is fair to assume that what you observed with both bins and scope, must have been between you and the Planet. As already mentioned, observations of Mars through bins, would only reveal a small Red dot. If a line was observed, then it must have been of a very thick cross section. With the low elevation, are there any distant major grid power pylons within your observational path.

It does help matters a lot, when reporting observations of this type, if you can supply a little more detail, optical instrument in use, time, direction and elevation of sight and observing conditions

[Gina]

Earlier observers of Mars saw canals - there aren't any!  Maybe that applies to lines as well?

[Aaron F Johnson]

Here are Mr. Lowells canals, how he ever seen this though a scope I can only wonder...but canali in Italian meaning channels can be found on mars but without the translation Lowells dedicated mind must have created his depiction...I think powerlines are what was seen but cool the canals myth is still an interesting story...

 Public domain image.

[hes not well again]

Didn't Lowell have a eye condition that accounts for him seeing what isn't there?

[Aaron F Johnson]

He had a rare desease that allowed him to see the blood vessels in his own eyes but he was aware of this and able to disern the vessels from what was seen in his telescope or so he claimed. I have never seen the name of the desease printed anywhere (pretty rare I guess). His best contribution to astronomy is that he was the supposed first to build and place observatories in high locations away from cities were their operations would be more viable for doing  astronomical studies. I put the supposed bit in because ancient civilizations built stairways to the stars in remote elevated locations and studied the heavens from those locations as well leaving behind proof of those studies, the constellations come to mind and there are others. Lowell just reminded us. This is how you do it you silly forgetful humans.