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Cosmic Freezer

Short answer: The coldest place in the universe isn't the void between galaxies. It's a dying star's breath, 5,000 light-years away, at 1 K (-272 °C).

Did you think empty space was the coldest place out there?

Slides · 10Write-up5 sources

In collections:Extreme Cold

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What should you know about Cosmic Freezer?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. The Boomerang Nebula: A cloud of gas blown off by a dying star, about 5,000 light-years away in Centaurus.

    DD-752-F01 · Slide 02 · Exhibit A

  2. 1 Kelvin: That's -272 °C / -458 °F. Just one degree above absolute zero.

    DD-752-F02 · Slide 03 · Exhibit B

  3. Colder than space: The Big Bang's afterglow keeps empty space at about 2.7 K. The Boomerang is colder.

    DD-752-F03 · Slide 04 · Exhibit C

  4. The only one: It's the only known natural object colder than the cosmic background.

    DD-752-F04 · Slide 05 · Exhibit D

  5. Found in 1995: Sahai and Nyman measured it with the 15-metre SEST radio telescope in Chile.

    DD-752-F05 · Slide 06 · Exhibit E

  6. 164 km per second: Its star blasts gas outward at over 500,000 km/h.

    DD-752-F06 · Slide 07 · Exhibit F

  7. 1/1,000 of a Sun: That's how much mass it sheds every year, for at least 1,500 years.

    DD-752-F07 · Slide 08 · Exhibit G

  8. A cosmic fridge: The gas expands so fast it chills itself. Same trick as your refrigerator.

    DD-752-F08 · Slide 09 · Exhibit H
The coldest place in the universe isn't empty space. It's a dying star 5,000 light-years away.
The Boomerang Nebula A cloud of gas blown off by a dying star, about 5,000 light-years away in Centaurus.
1 Kelvin That's -272 °C / -458 °F. Just one degree above absolute zero.
Colder than space The Big Bang's afterglow keeps empty space at about 2.7 K. The Boomerang is colder.
The only one It's the only known natural object colder than the cosmic background.
Found in 1995 Sahai and Nyman measured it with the 15-metre SEST radio telescope in Chile.
164 km per second Its star blasts gas outward at over 500,000 km/h.
1/1,000 of a Sun That's how much mass it sheds every year, for at least 1,500 years.
A cosmic fridge The gas expands so fast it chills itself. Same trick as your refrigerator.
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The write-up

The coldest place in the universe isn't empty space. It's a dying star 5,000 light-years away.

  1. Exhibit A

    The Boomerang Nebula

    A cloud of gas blown off by a dying star, about 5,000 light-years away in Centaurus.

  2. Exhibit B

    1 Kelvin

    That's -272 °C / -458 °F. Just one degree above absolute zero.

  3. Exhibit C

    Colder than space

    The Big Bang's afterglow keeps empty space at about 2.7 K. The Boomerang is colder.

  4. Exhibit D

    The only one

    It's the only known natural object colder than the cosmic background.

  5. Exhibit E

    Found in 1995

    Sahai and Nyman measured it with the 15-metre SEST radio telescope in Chile.

  6. Exhibit F

    164 km per second

    Its star blasts gas outward at over 500,000 km/h.

  7. Exhibit G

    1/1,000 of a Sun

    That's how much mass it sheds every year, for at least 1,500 years.

  8. Exhibit H

    A cosmic fridge

    The gas expands so fast it chills itself. Same trick as your refrigerator.

Questions people ask about Cosmic Freezer

About how cold is the Boomerang Nebula?

About 1 Kelvin, or -272 °C / -458 °F, one degree above absolute zero.

Source: Slide 03 · Exhibit B (1 Kelvin)

What keeps empty space at about 2.7 K?

The Big Bang's afterglow keeps space at about 2.7 K, and the Boomerang is colder than that.

Source: Slide 04 · Exhibit C (Colder than space)

Which telescope did Sahai and Nyman use to measure it in 1995?

Sahai and Nyman found it in 1995 with the 15-metre SEST radio telescope in Chile.

Source: Slide 06 · Exhibit E (Found in 1995)

How does the nebula get so cold?

The gas expands so fast it chills itself, the same trick a refrigerator uses.

Source: Slide 09 · Exhibit H (A cosmic fridge)

How fast does its star blast gas outward?

About 164 km per second, which is over 500,000 km/h.

Source: Slide 07 · Exhibit F (164 km per second)

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. About how cold is the Boomerang Nebula?

    1. 1 K
    2. 2.7 K
    3. 10 K
    4. 77 K
    Show the answer

    Answer: A. 1 K About 1 Kelvin, or -272 °C / -458 °F, one degree above absolute zero. Source: Slide 03 · Exhibit B (1 Kelvin)

  2. What keeps empty space at about 2.7 K?

    1. Starlight from the Milky Way
    2. The Big Bang's afterglow
    3. Cosmic rays
    4. Dark matter
    Show the answer

    Answer: B. The Big Bang's afterglow The Big Bang's afterglow keeps space at about 2.7 K, and the Boomerang is colder than that. Source: Slide 04 · Exhibit C (Colder than space)

  3. Which telescope did Sahai and Nyman use to measure it in 1995?

    1. Hubble Space Telescope
    2. The Very Large Array
    3. The 15-metre SEST radio telescope in Chile
    4. The Arecibo dish
    Show the answer

    Answer: C. The 15-metre SEST radio telescope in Chile Sahai and Nyman found it in 1995 with the 15-metre SEST radio telescope in Chile. Source: Slide 06 · Exhibit E (Found in 1995)

  4. How does the nebula get so cold?

    1. It sits in a black hole's shadow
    2. It has no star at its center
    3. It is made of ice
    4. Its gas expands so fast it chills itself
    Show the answer

    Answer: D. Its gas expands so fast it chills itself The gas expands so fast it chills itself, the same trick a refrigerator uses. Source: Slide 09 · Exhibit H (A cosmic fridge)

  5. How fast does its star blast gas outward?

    1. 16 km per second
    2. 164 km per second
    3. 1,640 km per second
    4. Light speed
    Show the answer

    Answer: B. 164 km per second About 164 km per second, which is over 500,000 km/h. Source: Slide 07 · Exhibit F (164 km per second)

Cite this case file

Easterling, Marcus. "Cosmic Freezer." The Detail Department (DetailEnjoyer), case file DD-752, last updated Oct 17, 2026. https://detailenjoyer.com/case/coldest-place-universe-v2/

Permalink: https://detailenjoyer.com/case/coldest-place-universe-v2/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-752-F01 → https://detailenjoyer.com/case/coldest-place-universe-v2/#DD-752-F01

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