Illustration of the interior of 55 Cancri e — an extremely hot planet with a surface of mostly graphite surrounding a thick layer of diamond, below which is a layer of silicon-based minerals and a molten iron core at the center. (Image by Haven Giguere)

It’s not surprising that astronomers are discovering new planets almost every day. Almost all of them are the same boring type as our old Earth — wisps of gas and dust orbiting around a star that, under the influence of their mutual gravitation, gradually accrete into planet-sized bodies. But last year, Yale researchers found out that a big planet, twice the size of Earth, is apparently the core left when a great supernova blew most of its gases way.

The remaining core was carbon. Under the influence of ts own brutal gravity it crystallized its entire mass, And what is floating around out there — fortunately for the De Beers company, too far away for anybody to even think of mining it — is a gigantic diamond, the size of the planet Jupiter.

If there is a race of super-huge, super-intelligent aliens out there, what an engagement ring for their emperor to give his fiancee.


  1. Stefan Jones says:

    This reminds me of a Poul Anderson novel (Mirkheim). The surface of a world circling a supernova remnant was plated with various sorts of unobtanium produced by the blast. Super-heavy elements, if I remember right.

  2. H. E. Parmer says:

    And in a less Ritzy section of the galaxy, a cubic zirconia three times the size of the Earth has been discovered …

  3. Gregory Benford says:

    I wrote a novella in the 1980s “A Diamond As Big as the Ritz” — based on planetary simulations of that time. So this is a brilliant discovery… note the Fitzgerald ref too.
    Hi Fred!