Comments on: Earthrise

By: See you at Enceladus » Blog Archive » A Bit of Ego Stroking, and a Lot of Modesty

Thu, 22 Jun 2006 22:07:57 +0000

[...] First, via the Bad Astronomy Blog: [...]

By: Troy

Troy — Wed, 21 Jun 2006 22:42:54 +0000

I’ve always thought that 1% of pictures from spacecraft should be dedicated to capturing the asthetics of that unique environment. I’m not certain but I believe Galileo (spacecraft) could have imaged Amalthea as it did a final pass during its deorbit around Jupiter and no attempt was made because of a NASA policy that all images must be scientificly analyzed and that would have taken money which wasn’t originally allocated for the dying spacecraft.
The Voyager image of the solar system was pure genius. It had no scientific merit, but it is one of my favorites.
Regarding the Buzz Parsec question on how much easier Jupiter’s satellites would be, I did a check with Redshift which allows you to do astronomy from the surfaces of other planets. When Jupiter is at opposition Ganymede’s magnitude would be 4.56 with Jupiter approximately 3.85 a.u. away. Compare this to Earth where Ganymede would be 4.83 magnitude. There is a significant difference but I think it would still be too dim to see. On the other hand Earth’s moon would be quite visible so perhaps heliocentrism would have been an easier bite to swallow. Of course even when people are shown proof there can still be resistance to new ideas.

By: Robert Carnegie

Robert Carnegie — Wed, 21 Jun 2006 21:07:25 +0000

There’s a touching episode in C. S. Lewis’s _Out of the Silent Planet_, a sort of theological science fiction story. An Earthman stranded on another planet (Bad Astronomy: Martian canals) runs into an alien astronomer, who forms the opinion that the refugee’s home planet is Thulcandra, an ill-favoured place in their astronomy and their religion – and it is; he sees a small but detailed spot in a mysterious telescope, recognisable but rather sadly upside down. He is deeply saddened.

Joe: my MSIE says that https http://www.planetary.org/bluedot_poster.html has a wonky security certificate, so I don’t think I want to go. But it sounds lovely.

By: icemith

icemith — Wed, 21 Jun 2006 17:09:24 +0000

Grrrrr. …Flashes OF light… in first para. ( I missed that typo. and a couple of minor ones).

Ivan

By: icemith

icemith — Wed, 21 Jun 2006 17:03:00 +0000

I too noticed the spurious flashes if light in separated frames. One appears at , it seems, 90 degree orbital intervals. Obviously not the moon as it takes 28 days to cover full orbit. It does ‘orbit’ in the right curves, but the few sample shots would be far too few to define that orbit anyway. It is only a 29 minute window of the scene, so the orbital movement of the Moon in that time is negligible.

Linking to JPL’s Simulator and adjusting the various options, shows the Moon is close to the Earth from the viewpoint of Mars, and true, it must be in the general direction of the Sun. However, the Sun at that distance would not present as much glare as it would from Earth. But there may be a problem if the Moon is on the nearer side of Earth to Mars, the disk of the Moon would hardly be visible as it would be the dark side.

One thing I could not determine though, was the time exactly that corresponded to the 04:25 hours, ‘local time’ that the exposures started. Does it refer to the Mars time, GMT or US Eastern Standard? And how does one convert it anyhow? But I did notice though that plugging in ANY time for that day in Dec. 2005, gave little difference.

Ivan

By: Piles Of Rock

Piles Of Rock — Wed, 21 Jun 2006 16:06:54 +0000

Astronomy is cool…

Happy summer solstice everyone! The days only get shorter from here on out. Check out this picture of the Earth rising over Mars, like the Apollo pictures of the Earth rising over the moon, it really gives you a sense……

By: Tom

Tom — Wed, 21 Jun 2006 15:41:44 +0000

I ran a sim on Starry Night. Mars’ moons were well out of sight of this image. Looks like it was just two coincident ‘blips’

By: Graham

Graham — Wed, 21 Jun 2006 15:16:17 +0000

Seeing that makes we wish that we’d had a probe like that on Mars in back in the 1980′s and seen if there really was a Transit of Earth across the Sun as claimed by Arthur C. Clarke in the story of the same title.

By: Tambo

Tambo — Wed, 21 Jun 2006 15:07:22 +0000

There are a bunch of things whizing around there. This a way cool!Thanks for posting this!

By: Nick B.

Nick B. — Wed, 21 Jun 2006 15:05:23 +0000

Oh, and just to clarify, “opposition” refers to when both planets are on the SAME side of the sun, if I’m not mistaken.

By: Tom

Tom — Wed, 21 Jun 2006 12:39:57 +0000

I’m pretty sure it’s an optical illusion, but to me there appears to be a third object to the right of Earth moving from top to bottom very quickly (two frames, leading to my optical illusion theory) about 1/4 of the way through the motion gif. It’s either two well-placed photo imperfections or aMartian moon. If it were the latter, I’d think that the site would comment on it.

By: Angus McPresley

Angus McPresley — Wed, 21 Jun 2006 09:39:47 +0000

Any guesses as to what the dim streak of light that appears in one of the frames (near the lower left corner) might be?

By: Buzz Parsec

Buzz Parsec — Wed, 21 Jun 2006 05:01:33 +0000

I’ve always wondered (well, not *always*, but ever since I thought of it several years ago), if a Martian Galileo would have a much easier time with the Inquisition given the naked-eye example of the Moon orbiting the Earth. I wonder, could
you see the 4 Galilean moons of Jupiter from Mars? (Without a telescope, that is.) Since it’s closer to Jupiter, they would be brighter and more importantly, farther from Jupiter. But Jupiter would be brighter too, so there would be more glare. But on yet another hand, the seeing would be perfect!

I too would have liked to see the Moon in these pictures.

By: Jack Hagerty

Jack Hagerty — Wed, 21 Jun 2006 02:15:44 +0000

Blake Stacey clarifies: “The Pancam page says, ‘Earth is the brighter dot moving up the center of the field; Jupiter is the slightly dimmer dot coming in to the field in the upper left, later.’”

Thank you. As usual, I “assumed” incorrectly.

James opines: “Earth will show a (as good as) full disk to Mars at opposition, as Venus does to Earth. If Jupiter is also at opposition, it will be much farther away from Mars than Earth is.”

Yes, but it will never be a full disk until it (the Earth) passes directly behind the sun. Also, Jupiter being at opposition is exactly what I meant about “the right side of its orbit.”

- Jack

By: Babbler

Babbler — Wed, 21 Jun 2006 01:34:00 +0000

Wonderful. Really puts things in perspective.

By: DIguana

DIguana — Wed, 21 Jun 2006 00:41:42 +0000

Rememberâ€“ that speck of light you see in the image is us. You are in that picture. Iâ€™m in that picture. Everyone you know is in that picture, on that tiny mote of light.

Actually, wouldn’t only half of us be in that picture? (Well, probably not exactly half, since the human population isn’t distributed uniformly over the Earth’s surface, but you get the idea.)

By: i-Science » Blog Archive » Smile, you’re on camera

i-Science » Blog Archive » Smile, you’re on camera — Tue, 20 Jun 2006 21:20:20 +0000

[...] Found via Bad Astronomy. Explore posts in the same categories: Science, Astronomy [...]

By: Blake Stacey

Blake Stacey — Tue, 20 Jun 2006 21:14:25 +0000

Here's a fun tidbit. What looks like it's missing from this picture? Hint: it's 3,476 kilometers in diameter, and twelve people walked on it. I was curious why the Moon didn't show up on the Pancam photos, so I hopped over to JPL's Solar System Simulator and asked for a view of Earth from Mars on 29 December 2005. The result shows that the Moon is too close to the Earth to be made out as a separate body. . . neat.

By: Clance McClannahan

Clance McClannahan — Tue, 20 Jun 2006 21:08:56 +0000

Wow! Too cool. Every person who is now, or ever has been on earth is in that photo.
Love it!! Love your blog!

By: Blake Stacey

Blake Stacey — Tue, 20 Jun 2006 21:06:44 +0000

The Pancam page says, “Earth is the brighter dot moving up the center of the field; Jupiter is the slightly dimmer dot coming in to the field in the upper left, later.”

By: James

James — Tue, 20 Jun 2006 20:12:21 +0000

Earth will show a (as good as) full disk to Mars at opposition, as Venus does to Earth. If Jupiter is also at opposition, it will be much farther away from Mars than Earth is.

By: Joe Victorino

Joe Victorino — Tue, 20 Jun 2006 20:07:53 +0000

I love seeing views of Earth like that.
My favorite has to be the one Carl Sagen pushed so hard for. It is an image from Voyager looking back at Earth.
https://www.planetary.org/bluedot_poster.html

By: Jack Hagerty

Jack Hagerty — Tue, 20 Jun 2006 20:05:44 +0000

I’m not sure which is which. I presume the brighter one is Jupiter since it’s so much larger than Earth and Mars could be closer to it (if it’s on the right side of its orbit). Also, since Earth is inferior to Mars, it will never show a whole disk.

- Jack

By: Michelle Rochon

Michelle Rochon — Tue, 20 Jun 2006 19:56:26 +0000

Awesome! I always wondered… What would our planet look like from Mars? Mars is already nice to look at, and it’s smaller than Earth! It should be really a awesome view in a scope.