APOD: Northern Mercury (2012 Dec 01)

[1yioi87]

Chris,

Thank you for your response. It was complete and did not talk down to a non astronomer. I appreciate your knowledge and time.

Merry Christmas

Cliff
cwb@satx.rr.com

[1yioi87]

I thought I responded to Chris but don't see it posted here. I wanted to thank him for being kind to an non astronomer and for taking the time to answer my questions. I appreciate his knowledge and his reply.

While I am at it a note of thanks for every one who took time to respond.

Thanks,
Cliff

[geckzilla]

It's worth noting that the forum is composed of many people from different backgrounds and that almost none of us here are astronomers. Chris is one of the few qualified to answer astronomy questions with more than a link to a Wikipedia article.

[neufer]

Chris is one of the few qualified to answer astronomy questions with more than a link to a Wikipedia article.

You have cut me to the quick

[owlice]

She said "one of the few." Neufer, you are definitely one of them!

[geckzilla]

Art, despite all of your posting, I still have no idea who you are! And don't you dare give me some quote box containing information about that MAD magazine mascot.

[flash]

"The polar ice deposits imaged by Earth-based radar are in yellow."

When I first saw the image I had assumed that the radar that discovered the ice in craters at the north pole of Mercury was "Messenger-based", not "Earth-based". I wonder how an Earth-based radar could see into the craters on Mercury that the sun's rays cannot reach. Are the orbital planes of Earth and Mercury inclined to each other sufficiently that we can periodically look down onto the poles of Mercury? The resolution to be able to do this (and all the other things we do) is astounding.

Of course, even "Messenger-based" radar is in a sense "Earth-based" since that's where Messenger originated, but I think that's not how it was meant. Where was the radar?

[Chris Peterson]

I wonder how an Earth-based radar could see into the craters on Mercury that the sun's rays cannot reach. Are the orbital planes of Earth and Mercury inclined to each other sufficiently that we can periodically look down onto the poles of Mercury?

Yes- the difference in inclination between Mercury's and Earth's orbital planes is about 7°.

The resolution to be able to do this (and all the other things we do) is astounding... Where was the radar?

Arecibo. Big aperture, high resolution.

[neufer]

Art, despite all of your posting, I still have no idea who you are!

I'm a retired NOAA physicist & MIT grad with 4 grandchildren (2 nearby), 3 children (2 nearby) & a wife (1 nearby) .

I have a home in Maryland but mostly reside at my 95 year old mother's house in Alexandria,Va. (about three blocks from where I grew up and walked to elementary school).

I have 8,500 posts at the Starship Asterisk*
but 27,000 posts at humanities.lit.authors.shakespeare
(so I gotta bita catchin' up to do).

[Ann]

Art, despite all of your posting, I still have no idea who you are!

I'm a retired NOAA physicist & MIT grad with 4 grandchildren (2 nearby), 3 children (2 nearby) & a wife (1 nearby) .

I have a home in Maryland but mostly reside at my 95 year old mother's house in Alexandria,Va. (about three blocks from where I grew up and walked to elementary school).

I have 8,500 posts at the Starship Asterisk*
but 27,000 posts at humanities.lit.authors.shakespeare
(so I gotta bita catchin' up to do).

Art, not to get you started, but I can't help wondering what you said about the Bard or the Earl in those 27,000 posts.

Okay, forget I brought it up!

Ann

[owlice]

Art, not to get you started, but I can't help wondering what you said about the Bard or the Earl in those 27,000 posts.

Ann

Ann, he provided a link; you could go read his posts there, you know.

[neufer]

The resolution to be able to do this (and all the other things we do) is astounding... Where was the radar?

Arecibo. Big aperture, high resolution.

Arecibo's big aperture was important for its signal to noise not for its resolving power.

Radar resolution comes totally from a combination of temporal & frequency resolution of the returning radar pulse.

With enough power and observation time a 10 meter radar dish could have done the same.

[geckzilla]

Art, despite all of your posting, I still have no idea who you are!

I'm a retired NOAA physicist & MIT grad with 4 grandchildren (2 nearby), 3 children (2 nearby) & a wife (1 nearby) .

I have a home in Maryland but mostly reside at my 95 year old mother's house in Alexandria,Va. (about three blocks from where I grew up and walked to elementary school).

I have 8,500 posts at the Starship Asterisk*
but 27,000 posts at humanities.lit.authors.shakespeare
(so I gotta bita catchin' up to do).

So Arthur Neuendorffer is your real name?

[neufer]

So Arthur Neuendorffer is your real name?

A.C.Ne. : that's me.

My dad (Joseph Alfred Neuendorffer) once went to court to get his name legally changed.

He didn't like the name "Joe" since it was too common.

(The judge rejected his petition.)

[Chris Peterson]

Arecibo's big aperture was important for its signal to noise not for its resolving power.

For imaging radars, resolution is determined significantly by the S/N.

Radar resolution comes totally from a combination of temporal & frequency resolution of the returning radar pulse.

The precision of each being determined by S/N.

With enough power and observation time a 10 meter radar dish could have done the same.

Only in theory. In practice, radar imaging of other planets at high resolution is only possible with very large aperture radio telescopes.

[Anthony Barreiro]

Art, despite all of your posting, I still have no idea who you are!

I'm a retired NOAA physicist & MIT grad with 4 grandchildren (2 nearby), 3 children (2 nearby) & a wife (1 nearby) .

I have a home in Maryland but mostly reside at my 95 year old mother's house in Alexandria,Va. (about three blocks from where I grew up and walked to elementary school).

I have 8,500 posts at the Starship Asterisk*
but 27,000 posts at humanities.lit.authors.shakespeare
(so I gotta bita catchin' up to do).

You are a true Renaissance man!

[neufer]

---

<<This high-incidence angle image highlights a pair of newly named craters, Kobro and Komeda. Both craters exhibit prominent central peaks, and are located near Mercury's South Pole. Kobro crater, named for the Polish sculptor Katarzyna Kobro (1898-1951) is located near the center of the image, while Komeda, named for the Polish composer and musician Krysztof Komeda (1931-1969) is located just to the southeast. The craters are of approximately the same size, and appear to share a rim.

This image was acquired as part of MDIS's high-incidence-angle base map. The high-incidence-angle base map is a major mapping activity in MESSENGER's extended mission and complements the surface morphology base map of MESSENGER's primary mission that was acquired under generally more moderate incidence angles. High incidence angles, achieved when the Sun is near the horizon, result in long shadows that accentuate the small-scale topography of geologic features. The high-incidence-angle base map is being acquired with an average resolution of 200 meters/pixel.>>