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NASA Sun-Watching Probe Sees Moon Mountains

When NASA launched the Solar Dynamics Observatory (SDO) in February 2010, engineers placed it in what’s called a geosynchronous orbit over Earth.

The idea is that the craft circles our planet at the same speed as Earth’s rotation about its axis. To an observer on the planet’s surface, the satellite seems to return to the same place in the sky at exactly the same time every day.

In SDO’s case, the orbiter traces a figure-eight over the Pacific that seems to hang from northern Mexico:

—Orbital map courtesy NASA/SDO

The benefit of geosynchronous orbit is that it allows SDO to almost constantly face the sun, collecting scads of data and beaming the results continuously back to mission control.

[5/5 UPDATE: A couple commentors have pointed out that a geosynched orbit alone doesn’t mean SDO is almost always in sunlight. This is the downfall of writing in a rush! I neglected to say that the orbit is also *inclined* with respect to Earth’s Equator, and the craft is flying pretty high—22,000 miles, or 36,000 kilometers, above the planet. Those factors contribute to the Earth seldom being in SDO’s line of sight.]

Occasionally, though, the craft dips into Earth’s night side for two- to three-week periods, interrupting solar observations.

In addition, three times a year SDO will pass through the moon’s shadow, when our only natural satellite transits—or passes in front of—the sun, from the spacecraft’s perspective. (For a nice visual reference, see Bad Astronomer Phil Plait’s drawing of SDO’s orbital geometry.)

This morning astronomers using NASA’s Solar Dynamics Observatory captured one of these lunar transits against an image of the sun seen in extreme ultraviolet light. Click the image to zoomify.

—Picture courtesy NASA/SDO

As huge as the sun is, SDO is taking its pictures in such high resolution that you can even zoom in on the dark blot of the moon and see the bumps of mountains along its limb.

Such amazing views offer more than just a “wow” factor, too.

The SDO science team can use the hard features along the moon’s edge to calibrate their telescope, fine tuning the optics to make future images of our increasingly active sun even sharper.


  1. Daniel Prather
    Invergrove Heights, MN
    September 6, 2011, 5:20 pm

    Where can I find a picture of the sun, from the moon’s surface. I have to believe that there has been at least an attempt to capture this image.

  2. Dr. Aminur Rahman
    Dhaka, Bangladesh
    May 17, 2011, 8:33 am

    Its nice and amazing………………………………………through this I feel the power of the ALMIGHTY…also……

  3. […] NASA Sun-Watching Probe Sees Moon Mountains – National Geographic News Watch This entry was posted in Uncategorized. Bookmark the permalink. ← Google’s Chrome Laptops to Go on Sale in June – NYTimes.com LikeBe the first to like this post. […]

  4. chetanan
    May 14, 2011, 2:09 pm

    much ado about nothing

  5. […] that’s not natural color. National Geographic reports that the image was taken in extreme ultraviolet light so you can see the sun’s […]

  6. Vinay Kayath
    May 8, 2011, 6:23 am

    Oh! that’s amazing!!!!!! the solar flares of the sun can be seen clearly

  7. kanglasha
    May 7, 2011, 7:36 am

    now i realise why my mom worship THE SUN !!!
    Amazing photo…amazing nature

  8. kanglasha
    May 7, 2011, 7:28 am

    amazing creations of nature!!! Thanx to all the guys involved to capture the pix. Keep it up

  9. Isaque Leal
    May 6, 2011, 10:40 am

    When you see the creation, you are able to imagine a bit of the power of God.

  10. Faviola
    Cochabamba - Bolivia
    May 6, 2011, 9:57 am

    It is amazing!!!!!!

  11. maz
    May 6, 2011, 4:14 am

    amazing…….so beautiful…

  12. steve
    May 6, 2011, 2:59 am


  13. Abbas
    May 5, 2011, 6:11 pm

    When observed from earth, the moon and the sun look almost the same size – the moon completely covers the sun during solar eclipse; but in this shot, the moon definitely looks smaller than the sun – which means the ‘bite’ will never be able to eat the whole apple! I guess its because of the (greater) distance of SDO from the moon compared to an observer’s on the earth. Right?

  14. katie
    New York
    May 5, 2011, 5:47 pm

    This has NOTHING to do with religion! This is possible through science and science alone!

    Amazing processes and how fantastic that we are finally able to witness them!

  15. TAYO
    Lagos Nigeria
    May 5, 2011, 1:50 pm

    Nice one i love the image…

  16. memee
    May 5, 2011, 1:40 pm

    zomg it look soo kkewll :PPPP

  17. Kotcherlakota Lakshmi Narayana
    17-11-10 Narasimha Ashram, Official colony, Maharanipeta.P.O.,Visakhapatnam, Andhra Pradesh , India
    May 5, 2011, 11:14 am

    Glad you ahve sent me the details of the new observations of the Moon by the NASA satellite. I am thrilled to read that “This morning astronomers using NASA’s Solar Dynamics Observatory captured one of these lunar transits against an image of the sun seen in extreme ultraviolet light” Also its splendid that ” In SDO’s case, the orbiter traces a figure-eight over the Pacific that seems to hang from northern Mexico:” Pictures are exciting.

  18. ebbadet
    May 5, 2011, 10:58 am


  19. Fabio
    Rio de Janeiro
    May 5, 2011, 8:20 am

    exactly what will kill us, “coronal mass ejection”
    will be beautiful when the earth will be exterminated!

  20. Victoria Jaggard
    May 5, 2011, 8:05 am

    Thanks, @Phil Hoskinson! I was going to add that SDO’s orbit is inclined with respect to Earth’s Equator (see the orbital diagram linked in the text), and that it’s orbiting at an altitude of 22,000 miles (36,000 kilometers). So, as you say, it can almost continuously see the sun. As for synchronous vs. stationary, I just wanted to be clear that the craft is not locked over one particular point on Earth.

  21. Syed Hasan Abbas
    May 5, 2011, 7:47 am

    Could i get these images [esp. the middle one] in high resolution i.e. at least the wallpaper size?

  22. type_6
    May 5, 2011, 6:11 am

    Miracle :))

  23. Phil Hoskinson
    May 5, 2011, 5:15 am

    Again, no expert just enthusiastic. and apologies for lazy spelling

  24. Phil Hoskinson
    May 5, 2011, 5:14 am

    @Victoria Jaggard & john macpherson. geosync and geostat are essentially the same thing (it stays roughly in same area of sky as observed from earth). Due to the tilt of the earth and the distance the satelite has to be it can see the sun almost all the time apart from around the equinoxes when the earth will eclipse the sun every 24 hours as they will be pretty much in line.

  25. rini
    May 5, 2011, 3:00 am

    great !!!!

  26. Caximiro
    May 5, 2011, 2:54 am

    its amazing…

  27. Joe Bauwens
    May 5, 2011, 1:34 am

    I’m afraid I’m with John MacPherson. If the Satellite remains on the same line of longitude as Mexico, it’s going to go round the Earth once every 24 hours. Mexico does.

  28. Madhav
    Hyderabad, India
    May 5, 2011, 12:21 am

    Amazing photos.

  29. Helen Gilbert
    May 4, 2011, 11:45 pm

    Wow!That is really spectactcular.

  30. Victoria Jaggard
    May 4, 2011, 10:47 pm

    @john macpherson: I admit I’m not exactly an expert either, but I think you might be confusing geosynchronous orbit with geostationary. As I understand it, one is a subset of the other. For a more technical description, check out: http://www2.jpl.nasa.gov/basics/bsf5-1.php

  31. Michelle Reyes
    May 4, 2011, 10:30 pm

    Pretty Cool.

  32. nica
    new york
    May 4, 2011, 10:29 pm

    is the picture of the sun is true.. its so amazing!!1

  33. WAYNE & KIM
    Eastern Ontario, Canada
    May 4, 2011, 10:06 pm


  34. low profil
    May 4, 2011, 9:57 pm

    Anas Ahmed that’s right

  35. SUTSVART Wongkovit
    May 4, 2011, 8:30 pm

    These images would be great in paintings too.

  36. Judy
    May 4, 2011, 8:17 pm

    I love National Geographic. They share the most splendid pictures and detailed information . Would love to see this on the television network each month.

  37. john macpherson
    May 4, 2011, 8:00 pm

    Oh, well, as long as I am bitching, the rotation rate is the same, not the rotational speed. Also it dosen’t return from anywhere as it is always there. Oh also the reason the scientists call it a geosynchronous orbit is because that is what it is. The images, I agree, are really cool Or hot since it is the sun after all.

  38. Prateek Bagri
    May 4, 2011, 7:53 pm

    This is amazing!!

  39. john macpherson
    May 4, 2011, 7:52 pm

    a geosynchronous orbit is one that rotates the earth in 24 hours so it stays in the same place over the earth (or like the figure eight shown). So it is in daylight and night every 24 hours just like the place it is over. I think the author of the article doesn’t know what he is talking about, but then neither do I.

  40. jeffrey maravillas
    May 4, 2011, 7:42 pm


  41. Karen Christian
    East Ballina, NSW, Australia
    May 4, 2011, 7:22 pm

    I’ve just done the same as Twilight Wade, made it my desktop wallpaper. Stunning photo.

  42. carter
    May 4, 2011, 7:01 pm

    wow. . . that’s pretty cool. . .

    thanks for posting. . .

  43. Rosita
    May 4, 2011, 7:01 pm


  44. mpiew
    May 4, 2011, 6:43 pm

    Oh My God..It’s amazing,but make me scary..

  45. Kevin Newby
    May 4, 2011, 6:16 pm

    Nice pictures keep up the good work.

  46. AWAIS
    May 4, 2011, 6:05 pm


  47. eslam
    May 4, 2011, 5:44 pm


  48. Junaed Islam
    May 4, 2011, 5:24 pm

    What’a picture of our Sun !!! \m/ thanks Net Geo to bring it from NASA.

  49. Shawn Paunchai-Green
    May 4, 2011, 5:10 pm

    It’s a symbol of NATURE.

  50. John Gichuhi
    May 4, 2011, 5:04 pm

    Wonderful Innovation+++

  51. Angelica
    May 4, 2011, 5:02 pm

    Amazing 😀 the sun looks so awesome, I love those dancing beams of light coming out of it & to see the moon’s mountain’s detail, such beautiful photography <3

  52. Anas Ahmed
    May 4, 2011, 5:02 pm

    Yes! Only Allah can do this!

  53. Pankaj
    May 4, 2011, 4:50 pm

    It’s amazing!

  54. Pankaj
    May 4, 2011, 4:49 pm

    That’s amazing!

  55. vyte
    May 4, 2011, 4:43 pm

    in our life we have sun and love..i love it and i ‘m happy with it..

  56. Alfonsz
    May 4, 2011, 4:42 pm

    amazing cool

  57. vyte
    May 4, 2011, 4:40 pm

    in our life we have sun and love…i love it…

  58. Izabel
    May 4, 2011, 4:39 pm

    that´s amazing

  59. Zeeshan Ahmed
    May 4, 2011, 4:22 pm

    its a symbol of GOD….

  60. https://me.yahoo.com/a/46wWixVzlMCtckC3L1ppBRO6VRLBQKlz41bDBGsOCjQ-#81e36
    May 4, 2011, 4:08 pm

    not so much amazing!!!!!!!!

  61. suhair
    May 4, 2011, 4:04 pm

    amazing view
    thanks for sharing

  62. Sharon Chambers
    May 4, 2011, 3:57 pm

    Absolutely magnificent

  63. […] See what it looks like when the moon “bites” the sun May 4th, 2011 Share | window.fbAsyncInit = function() { FB.init({appId: "", status: true, cookie: true, xfbml: true}); }; (function() { var e = document.createElement("script"); e.async = true; e.src = document.location.protocol + "//connect.facebook.net/en_US/all.js"; document.getElementById("fb-root").appendChild(e); }()); From nationalgeographic: […]

  64. Diaa
    May 4, 2011, 8:44 am

    Thats amazing!!!!!!!!!!

  65. mohamedkhaled
    May 4, 2011, 6:36 am

    it will be red

  66. hggh
    May 3, 2011, 10:36 pm

    soo cool

  67. Twilight Wade
    Redmond, WA
    May 3, 2011, 8:21 pm

    Absolutely beautiful. This just became my desktop wallpaper.
    Thanks for sharing.

  68. […] NationalGeographic […]

  69. christine miller
    May 3, 2011, 5:39 pm


  70. […] If you would like to see images and read further please check out National Geographic. […]

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