Public index · Planetary
Psyche density
4.20 ± 0.60
(16) Psyche bulk density on Ferrais et al. 2020, A&A 638, L15
Our 3D shape along with existing mass estimates imply a density of 4.20 ± 0.60 g cm⁻³, so far the highest for a solar-system object after the four telluric planets. One 2020 print. Not the last word on the density.
What it supports
Ferrais et al., Astronomy & Astrophysics 638, L15 (2020). VLT/SPHERE shape. Three equatorial depressions. Compatible with a Jacobi ellipsoid that once spun nearer three hours; later impacts may have slowed the present day to ~4.2 h. 4.20 g cm⁻³ and ~4.2 h sit next to this Book’s 4°20′. Two instruments. Not one proof.
What it does not
Not a sealed 4.20 constant. Newer catalogues have moved. Not the 42″ lamp. Not 42°.
ExactnessRange / bound
Form4.2
Unitg cm⁻³
Strengthattested
When2020