New Observatory Is Now the Coldest Object in All of Space

By Allison Bond | July 7, 2009 5:40 pm

PlanckThe European Space Agency’s Planck observatory has reached its operating temperature of a mere tenth of a degree above the lowest temperature theoretically possible given the laws of physics, known as absolute zero. That means it’s ready for its mission: Observing the oldest light in the universe, known as the cosmic microwave background, or CMB, to create the clearest picture yet of what the young universe looked like.

Although scientists have achieved temperatures closer than this to absolute zero in the laboratory, the spacecraft is likely the coldest object in space. Such low temperatures are necessary for Planck’s detectors to study the Cosmic Microwave Background by measuring its temperature across the sky. Over the next few weeks, mission operators will fine-tune the spacecraft’s instruments. Planck will begin to survey the sky in mid-August [], and the first batch of data is expected to be released next year. Planck was launched May 14 and will observe the CMB from a spot more than 930,000 miles from Earth.

The frigid temperature in the spacecraft will enable it to take the most sensitive measurements ever recorded of the temperature variations of the cosmic microwave background, which was released only 380,000 years after the Big Bang. Previous space-based missions have found that the temperature of the CMB varies ever so slightly in different areas. Planck is built to resolve these variations in greater detail. Planck’s detectors will look for variations in the temperature of the CMB that are about a million times smaller than one degree – this is comparable to measuring from Earth the heat produced by a rabbit sitting on the Moon. []. The CMB could tell scientists more about how galaxies, galaxy cluster and the first stars were formed, based on the photons, or particles of light, that the CMB releases.

Lowering Planck to its operational temperature of -459.49 degrees Fahrenheit, or -273.05 Celsius, was no easy task. The remarkable conditions are maintained, in part, by always pointing Planck away from the heat of the Sun. Shields and baffling get the telescope down to about -220C. Three active refrigeration systems then lower the onboard environment at the heart of the observatory extremely close to the state of zero heat energy – when, theoretically, atoms would stop moving [BBC News]. Last week, Planck was maneuvered to its observation point at the second Lagrangian Point of the sun-Earth system, one of five points that, due to gravitational effects, allow the observatory to orbit at a constant speed.

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Image: ESA

CATEGORIZED UNDER: Physics & Math, Space
  • Quasar

    Actually a black hole is the coldest thing in the Universe!

  • Dan

    I’m pretty sure a rabbit sitting on the Moon is not going to be producing any heat.

  • Nick

    Actually, yes, it would be producing heat relative to the surrounding temperatures. Now, the question is, are you talking about the dark side or bright side of the moon. There is a several hundred degree difference between the two in temperatures. Also, you do know that space suits, besides containing atmosphere, are there to remove heat from the astronauts. Keeping them warm isn’t the problem, keeping them from cooking themselves is the problem.

    Considering the dark side of the moon is several hundred degrees below zero (F or C you ask? First one, then t’other), and the rabbit is approximately 36 degrees C, the rabbit would be glowing brightly in infrared compared to the dark surface of the moon, until the mass of the moon leached all the heat out of the dead rabbit’s corpse, and then the bun would remain, never decaying, another remnant of man’s foolish escapades on the moon. :p

    And black holes produce super-heated storms of plasma and charged particles around them due to the tidal forces of their gravity – the same tidal forces that can warm such moons as Europa and Enceladus. What goes on the beyond the event horizon of the black hole, what temperatures are achieved there? Science can’t tell us at the moment. We can’t see it. We can only observe it’s effects. Also, compression will create heat, and black holes do nothing if not compress things.

    Atoms stop moving at 0K… but do electrons stop as well? What about the quanta in the protons and neutrons that make up the nucleus? I guess we’ll find out at some point!

  • 6Speed

    I think Dan assumed the rabbit wasn’t wearing a space-suit and helmet.

  • MDR

    Nick needs to get a life

  • Chris

    you mean a rabbit sitting in a sound stage in Burbank!



    Rabbit on Moon: I knew I shoulda took that left toin at Albuquerque!

  • Jumblepudding

    I’m so cool, I’m cooler than both the Planck observatory and that rabbit on the moon. Dig it.

  • Kin

    Nick, oK is absolute zero. Nothing is moving. It also can’t really happen, so I’m not so sure about your questions. I’m pretty sure it can’t exist or cant be had because if the particle didn’t have any vibrational energy, it would not exist.

    Also. The rabbit dead. Make sense now?
    [6speed may have been subtle]

  • http://rotojunkie Larry C

    but if you could stop atoms from moving, would it spawn another universe.

    oooh look, a rabbit!

  • Skeptikor

    And can you imagine the terrible freezer burn? I hope that rabbit is well bagged.

  • My Reference Frame

    How long can they maintain this temperature on the spacecraft? I’m assuming since it won’t be pointed towards the Sun solar re-charging of power systems is out.


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