Human Journey

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.

  • […] wrote an interesting post today onHere’s a quick excerpt […]

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

  • christine miller


  • […] NationalGeographic […]

  • Twilight Wade

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

  • hggh

    soo cool

  • mohamedkhaled

    it will be red

  • Diaa

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

  • […] 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 + "//"; document.getElementById("fb-root").appendChild(e); }()); From nationalgeographic: […]

  • Sharon Chambers

    Absolutely magnificent

  • suhair

    amazing view
    thanks for sharing


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

  • Zeeshan Ahmed

    its a symbol of GOD….

  • Izabel

    that´s amazing

  • vyte

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

  • Alfonsz

    amazing cool

  • vyte

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

  • Pankaj

    That’s amazing!

  • Pankaj

    It’s amazing!

  • Anas Ahmed

    Yes! Only Allah can do this!

  • Angelica

    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

  • John Gichuhi

    Wonderful Innovation+++

  • Shawn Paunchai-Green

    It’s a symbol of NATURE.

  • Junaed Islam

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

  • eslam




  • Kevin Newby

    Nice pictures keep up the good work.

  • mpiew

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

  • Rosita


  • carter

    wow. . . that’s pretty cool. . .

    thanks for posting. . .

  • Karen Christian

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

  • jeffrey maravillas


  • john macpherson

    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.

  • Prateek Bagri

    This is amazing!!

  • john macpherson

    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.

  • Judy

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

  • SUTSVART Wongkovit

    These images would be great in paintings too.

  • low profil

    Anas Ahmed that’s right



  • nica

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

  • Michelle Reyes

    Pretty Cool.

  • Victoria Jaggard

    @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:

  • Helen Gilbert

    Wow!That is really spectactcular.

  • Madhav

    Amazing photos.

  • Joe Bauwens

    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.

  • Caximiro

    its amazing…

  • rini

    great !!!!

  • Phil Hoskinson

    @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.

  • Phil Hoskinson

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

  • type_6

    Miracle :))

  • Syed Hasan Abbas

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

  • Victoria Jaggard

    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.

  • Fabio

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

  • ebbadet


  • Kotcherlakota Lakshmi Narayana

    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.

  • memee

    zomg it look soo kkewll :PPPP

  • TAYO

    Nice one i love the image…

  • katie

    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!

  • Abbas

    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?

  • steve


  • maz

    amazing…….so beautiful…

  • Faviola

    It is amazing!!!!!!

  • Isaque Leal

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

  • kanglasha

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

  • kanglasha

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

  • Vinay Kayath

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

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

  • chetanan

    much ado about nothing

  • […] 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 – LikeBe the first to like this post. […]

  • Dr. Aminur Rahman

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

  • Daniel Prather

    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.

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