Comments on: The shadow of a moon goes passing by

By: Benjamin Franz

Benjamin Franz — Fri, 17 Dec 2010 15:21:44 +0000

@Dave Jerrard (#13): I got the T’Pau reference immediately when I saw the headline. Great song, great CD.

By: Messier Tidy Upper

Messier Tidy Upper — Fri, 17 Dec 2010 10:55:19 +0000

@ ^ Joseph : Try this one :

http://blogs.discovermagazine.com/badastronomy/2007/03/02/stereo-eclipse/

via the STEREO spacecraft & this very blog.

I’m afraid it’s not the Earth but the Sun instead but it’s still pretty impressive.

Then there’s this artwork by Don Dixon :

http://www.eso-garden.com/index.php?/weblog/total_lunar_eclipse_during_night_of_february_20_21/

But, yeah, I couldn’t find much on that specifically either despite a quick search of this blog, google images and Youtube.

By: Joseph

Joseph — Thu, 16 Dec 2010 22:50:51 +0000

Are there images from space of our moon’s shadow traversing the earth during a Total eclipse?

Or rather are there any good videos? A quick Google search reveals a black & white video that doesn’t work and a number of created animations.

I want NASA video footage in color!

By: Matt B.

Matt B. — Thu, 16 Dec 2010 21:36:04 +0000

What’s amazing is that that’s all penumbra. Phobos’ umbra reaches only one half to three fourths of the way down to Mars’ surface (depending on angle). Its penumbra is about 2.7 times its size (assuming a distance of about 7500 km from Phobos to Mars’ surface in this case), making it at most about 37 km wide (not counting the fact that it’s hitting the ground at an angle). I believe that’s smaller than our moon’s umbra.

By: PFINQ238

PFINQ238 — Thu, 16 Dec 2010 17:35:14 +0000

Thanks! It makes me feel very small; also old.

By: Keith Bowden

Keith Bowden — Thu, 16 Dec 2010 16:41:26 +0000

Thanks Dave (#13)! I’m glad I wasn’t the only one!

By: Pete Jackson

Pete Jackson — Thu, 16 Dec 2010 05:08:53 +0000

@No.5 Speedlimit186k: Such transits of the Earth-Moon system across the Sun as seen from Mars, although very rare, would be very beautiful. Imagine the extremely rare event where an occultation of the Moon by the Earth, or vice-versa, happened at the same time, as during a solar or lunar eclipse!

By: Gary Ansorge

Gary Ansorge — Thu, 16 Dec 2010 03:56:26 +0000

“the T’Pau reference?”

Perhaps you’re experiencing periodelia. I see nothing but the Shadow of The Death Star,,,

Great pic.

Gary 7

By: Dave Jerrard

Dave Jerrard — Thu, 16 Dec 2010 01:34:56 +0000

Am I the only one that got the T’Pau reference?

He Who Likes It With His Heart And Soul.

By: Kaveh

Kaveh — Thu, 16 Dec 2010 01:20:23 +0000

it took me at least 6 tries to see it!

By: Messier Tidy Upper

Messier Tidy Upper — Wed, 15 Dec 2010 23:55:36 +0000

Well spotted Daniel Macháček. Amazing.

Faint and subtle just a passing shadow – which I presume wasn’t animated like that when he first detected it but rtaher in a series of still shots right?

Goes to show its well worth going back over the old data ands images from old missions & that there’s still things in them we’ve missed first time around. Wonder what else is there that hasn’t been spotted yet?

Would be awesome seeing the transit from the Martian surface – but, yeah, you’d definitely want a good spacesuit and O2 supply.I wonder who will be the first human to see that in Real Life – and when and from which nation. How long yet will we have to wait for Humanity to land on Mars – in person rather than via robot surrogates.

I’m sure someone standing on the surface would laugh ruefully at describing the 100 km/hr gusts as “slow”. If they could breathe, that is.

As I understand it, the pressure in the martian atmosphere is exceedingly low and so even if the gusts are 100km there’s not much to them because the air is so thin and lacking in “weight.” I could be wrong though.

By: Keith Bowden

Keith Bowden — Wed, 15 Dec 2010 23:50:02 +0000

You’re ahead of me, QD – I finally glimpsed it at the end of my third pass and watched a fourth time. (Of course, at that point I felt a little dumb, but it was hard to see. Of course, for some reason I was expecting it to be a larger shadow coming from the right of the screen. Dunno why.)

I must be tired…

By the way, Phil – nice T’Pau allusion. (And if it was a coinkydink, then I am tired…)

By: QuietDesperation

QuietDesperation — Wed, 15 Dec 2010 23:29:49 +0000

Took me two tries to see it.

By: Michael Swanson

Michael Swanson — Wed, 15 Dec 2010 23:11:53 +0000

Are you sure it wasn’t one of those giant Martian amoebas you posted a picture of a while back?

http://blogs.discovermagazine.com/badastronomy/files/2010/11/mro_dunes_proctor.jpg

By: Office Casual

Office Casual — Wed, 15 Dec 2010 22:48:11 +0000

@ 4

Thanks, that seems so obvious now.

By: JScarry

JScarry — Wed, 15 Dec 2010 22:40:44 +0000

“I’m sure someone standing on the surface would laugh ruefully at describing the 100 km/hr gusts as “slow”.”

But since the air is so thin, would it even knock you over if you were standing there?

By: Speedlimit186k

Speedlimit186k — Wed, 15 Dec 2010 22:19:29 +0000

I would totally brave the Martian winds to see a Martian lunar transit. An Earthly planetary transit would be even better!

By: kuhnigget

kuhnigget — Wed, 15 Dec 2010 21:57:28 +0000

@ 3:

It appears elongated because it is elongated. For two reasons: 1) the moon itself is oblong, and more importantly, 2) the angle at which the sun was above the local horizon was fairly low, so the moon’s shadow is stretched out over a larger chunk of territory than if it had been high noon. Same effect as when your own shadow gets longer as the sun goes down.

By: Office Casual

Office Casual — Wed, 15 Dec 2010 21:31:16 +0000

The shadow appears elongated to me. Is that because the surface it’s passing over isn’t smooth? Any ideas?

By: La sombra de Phobos sobre una tormenta marciana — Amazings.es

La sombra de Phobos sobre una tormenta marciana — Amazings.es — Wed, 15 Dec 2010 21:29:59 +0000

[...] de fotos que mandó a la Tierra, se encuentran auténticas joyas como ésta que nos descubre Phil Plait en Bad Astronomy: la sombra del la luna Phobos paseando por encima de una tormenta de arena. El vídeo es un montaje [...]

By: Oli

Oli — Wed, 15 Dec 2010 21:12:53 +0000

I don’t see any stars so it must be fake.