WISE shuts its eye

By Phil Plait | March 24, 2011 7:00 am

One of my favorite space astronomy missions, WISE, has shut its eye for the last time.

This wasn’t unexpected, though! The Wide-field Infrared Survey Explorer was meant to be a short mission, mapping the sky in far-infrared light for a year or so. It needed coolant to chill its detectors, and that ran out last year. On February 1, 2011, it took this one, final image:

[Click to infrareddenate.]

That’s a shot of the constellation Perseus, which is along the plane of the Milky Way Galaxy and is thus littered with stars and dust. It’s very much like millions of other images WISE took in its time in space. Below are links to some of my favorite images from WISE, and you really should take a look. They are eerily beautiful, and tell us a lot about the Universe that our eyes cannot perceive.

My congratulations to all my friends at WISE on an amazingly successful mission!

Image Credit: NASA/JPL-Caltech/UCLA

Related posts:

Shocking star is shocking. Shocking, I say!
In galactic collisions, might makes right
A WISE view of a small neighbor
Warm dusty rings around a weird binary star (probably my favorite WISE pic!)
WISE finds the coolest stars. Literally.
The seven WISE sisters
A WISE flower blooms in space
The first spectacular views of the sky from WISE
WISE uncovers its first near-Earth asteroid!

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (18)

  1. Have they turned it off because it has gotten too “warm” (relatively speaking) to get useful data, or because someone decided not to “waste” any more money on it, even though it could get more useful data?

  2. Sam H

    Congrats on such a great mission, but why did it only ever have such a small amount of coolant? If your going to spend $320 million shouldn’t you try to get as much as you can out of that money and make the mission last longer?

  3. Trebuchet

    According to some, it was turned off because it was capable of detecting Nibiru! (As discussed in the Conspiracy Theories section of the BAUT forum, of course.)

  4. Caleb

    How are they planning to deorbit the satellite now that it’s been deactivated?

  5. Interestingly, I shot this very object last year in “broadband”:

  6. Chris

    You always think space is cold, but then you remember you have the sun warming everything up

  7. Ray

    Why did it run out of coolant? Weren’t they using a closed system?

  8. Caleb (4): From the WISE website (linked at the beginning of the article):
    “Now that the survey is complete, WISE is being put into hibernation. While the satellite sleeps and circles more than 500 kilometers (about 310 miles) above the Earth’s surface, the WISE team is busily preparing its data for two big public releases: one this April, and the final release in the spring of 2012.”
    So it looks like it’s not being de-orbited. Not sure what the long-term plans are – whether they hope to service it and restore coolant or what.

  9. “The Spacecraft will remain in hibernation without ground contacts awaiting possible future use.”¹

    1. WISE: Wide-Field Infrared Survey Explorer. UC Regents, 17 Mar 2011. Web. 24 Mar 2011. http://wise.ssl.berkeley.edu/.

  10. CB

    @ Ken B:

    They had already extended the mission once . It’s coolant actually ran out late last year, after which it got too hot for two of its detectors to work. Since then it’s been using the more near-infrared detectors to look for Near-Earth Objects, which they called NEOWISE. Now that it’s done that survey, I guess with the more interesting half of the instruments non-functional it’s not a priority anymore.

    So, long story short, a little from column A, a little from column B. :)

    @ Sam H

    Um, the amount of coolant needed to keep an object in space at 1 AU from the Sun at 15 Kelvin for a year isn’t exactly “small”. And they only spent $320 million because they kept the mission scope as what it is. To carry substantially more coolant is going to require a substantially bigger launch vehicle for substantially more cost.

    @ Caleb

    From what I understand, they aren’t planning to de-orbit it at all. Instead, they’re keeping it in hibernation, where it will await future contact from the ground in case we want to use it again.

    @ Ray

    Closed system or not, the key point is that the coolant, which in this case started as solid (solid!) hydrogen, eventually warmed up and couldn’t do it’s job anymore, which is absorbing heat from the telescope that it absorbed from the sun. So while I’m not sure if they vent the warmed hydrogen, it makes logical sense that they would do so, since otherwise that heat is still around.

    It’s not like in your car, where the coolant carries heat from your engine to your radiator, and air blowing over the radiator carries that heat away, which makes the coolant cool again so it can be cycled back through the engine to carry more heat away. In space, radiation of light is the only way to lose heat and it is vastly less effective than conduction/convection in an atmosphere.

    So the coolant has to start as cool as its ever going to get, and is only going to get warmer from there. Heat loss due to radiation will be negligible, and if it wasn’t, it would defeat the whole purpose since it would mostly be in infrared.

  11. CB:

    It’s not like in your car, where the coolant carries heat from your engine to your radiator, and air blowing over the radiator carries that heat away, which makes the coolant cool again so it can be cycled back through the engine to carry more heat away.

    <mode type=”ignorant_public”>
    So why didn’t they just include a big fan to blow the heat away?


  12. Damn! I thought we could call that shot, “Humanity – WISE at last”.

  13. Douglas Troy

    Wow Phil, I’m kind of surprised you didn’t go with the title:

    Eyes WISE Shut.

    Kubrick would have been proud.

  14. Crubb

    WISE was closed because it saw too many unidentified activities in our skies. It was noted that the facility could easily be hacked and that there was a great chance of the alien activity beaing leaked to the press. This is partof the wordwide gonspiracy to defreedomize the public and make them into alien slaves. Protest and keep WISE open and learn the truth. I don’t wanna get probed.

  15. voice

    2012 is the end of the world

  16. Messier Tidy Upper

    Well said, Bad Astronomer & seconded by me. WISE was one of my favourites too.

    My congratulations and commiserations to the WISE guys. I raise my glass and drink to WISE and it’s accomplishments.

    Farewell & thankyou Stardust too.

    Wonder if they’ve found any nearer than Proxima stars – or Tyche – and whether we’ll get any big news in the April info.release?! 😉

    PS. Thanks #8. Bill DeVoe & #10. CB for both your informative and enjoyable comments too. :-)


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