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I am now in the third week of my annual February birthday fund-raising drive. The first two weeks were good, but not record-setting.


There are still two weeks left in this campaign however. If you have been a regular reader and a fan of my work and have not yet donated or subscribed, please consider doing so. I take no ads, I keep the website clean from pop-ups and annoying demands (most of the time). Thus, I depend entirely on my readers to support me. Though this means I am sacrificing some income, it also means that I remain entirely independent from outside pressure. By depending solely on donations and subscriptions from my readers, no one can threaten me with censorship. You don't like what I write, you can simply go elsewhere.


You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:


1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.


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Perseverance’s depot of core samples, ready for pickup

Mosaic of Perseverance's core sample depot
Click for original image.

Overview map
Click for interactive map.

The Perseverance science team yesterday released the annotated mosaic above, cropped to post here, showing the scattered depot of core samples the rover deposited on the floor of Jezero Crater for later pickup some time next decade for return to Earth.

The overview map to the right shows the context. The blue dot marks Perseverance’s position when it took the picture, on January 31, 2023. The green dot marks Ingenuity’s location at that time. The yellow lines indicate the approximate area covered by the mosaic. The green outline indicates the area of the depot.

Eight of those tubes are filled with rock and regolith (broken rock and dust), while one is an atmospheric sample and one is a “witness” tube. The rover photographed the depot using the Mastcam-Z camera on the top of its mast, or “head,” on Jan. 31, 2023. The color has been adjusted to show the Martian surface approximately as it would look to the human eye.

The location of each tube was carefully mapped because it is possible wind will cover them with dust in the decade-plus before pickup. This mosaic will also act as a guide for the future Mars helicopters that will arrive to grab the core samples and bring them to an ascent spacecraft that will bring them back to Earth.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.

The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News


  • MDN

    Seems silly to spread them out like that. Aren’t the tubes stamped with serial numbers or something to make mapping what each sample is? It’s probably a nit given the advent and intent of rotorcraft for it but this seems like it unnecessarily complicates retrieval.

    And actually I don’t understand the idea of dropping them off the rover already anyway. Why not wait until the retrieval mission is there? Then we’d only need to get to one location and could get all the goods in one go. Seems like NASA might be feeling their oats a bit too recklessly after the success of the hideously complex JWST. But I bet this aspect of the Perseverance mission didn’t get tested and failsafed near as much

  • MDN: Please read this post about the logic behind the placement. There has been careful thought put into this, believe me.

    I know that we now rarely trust the work of government “experts”, but we must not assume always they are dumb or stupid. The success of both Mars rovers and Ingenuity as well as the orbiters tells us that the American planetary science and engineering community really does have its act together, and generally acts with common sense.

    Even though I am a big critic of government and NASA, I try to know my facts before criticizing. I now ask my readers to do the same. Too often I find the comments here to be quick off the cuff fault-finding, often without doing the slightest research, some of which I find can be accomplished by one ten second DuckDuckGo search. Sometimes the criticisms are made without even reading my entire post, or even clicking on the story I am linking to. This is unfair, and an example of the same kind of sloppiness that is leading us into a dark age.

    I would hope my readers could be better. Please prove my good opinion of you all is correct.

Readers: the rules for commenting!


No registration is required. I welcome all opinions, even those that strongly criticize my commentary.


However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.


Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.

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