Stories
Slash Boxes
Comments

SoylentNews is people

posted by martyb on Wednesday October 30 2019, @04:37AM   Printer-friendly
from the waiting-for-Snow-White-planets dept.

ESO Telescope Reveals What Could be the Smallest Dwarf Planet Yet in the Solar System

Astronomers using ESO's SPHERE instrument at the Very Large Telescope (VLT) have revealed that the asteroid Hygiea could be classified as a dwarf planet. The object is the fourth largest in the asteroid belt after Ceres, Vesta and Pallas. For the first time, astronomers have observed Hygiea in sufficiently high resolution to study its surface and determine its shape and size. They found that Hygiea is spherical, potentially taking the crown from Ceres as the smallest dwarf planet in the Solar System.

As an object in the main asteroid belt, Hygiea satisfies right away three of the four requirements to be classified as a dwarf planet: it orbits around the Sun, it is not a moon and, unlike a planet, it has not cleared the neighbourhood around its orbit. The final requirement is that it has enough mass for its own gravity to pull it into a roughly spherical shape. This is what VLT observations have now revealed about Hygiea.

"Thanks to the unique capability of the SPHERE instrument on the VLT, which is one of the most powerful imaging systems in the world, we could resolve Hygiea's shape, which turns out to be nearly spherical," says lead researcher Pierre Vernazza from the Laboratoire d'Astrophysique de Marseille in France. "Thanks to these images, Hygiea may be reclassified as a dwarf planet, so far the smallest in the Solar System."

The team also used the SPHERE observations to constrain Hygiea's size, putting its diameter at just over 430 km. Pluto, the most famous of dwarf planets, has a diameter close to 2400 km, while Ceres is close to 950 km in size.

Ceres, Vesta, Pallas, and Hygiea are the four largest asteroid belt objects. Saturnian moon Mimas is the smallest astronomical body known to be rounded due to self-gravitation, with a diameter of just 396 km.

Impact simulation video (34s).

Also at Ars Technica.

A basin-free spherical shape as outcome of a giant impact on asteroid Hygiea (open, DOI: 10.1038/s41550-019-0915-8) (DX)


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 0) by Anonymous Coward on Wednesday October 30 2019, @07:03AM (2 children)

    by Anonymous Coward on Wednesday October 30 2019, @07:03AM (#913612)

    It isn't round anyway, not even the Earth is round. There is a compelling consensus forming in conspiracy circles that the earth is more cone shaped with a dome over the top and antartica as a ring around the outer rim. You'll find debunkers on both sides of course, but that many people around the world couldn't be wrong... Unless that is just a distracting existential narrative designed to keep the powers that be in control.

  • (Score: 0) by Anonymous Coward on Wednesday October 30 2019, @10:37AM (1 child)

    by Anonymous Coward on Wednesday October 30 2019, @10:37AM (#913651)

    I have something that is cone shaped with a dome over the top. Maybe it's a planet too.

    • (Score: 0) by Anonymous Coward on Wednesday October 30 2019, @03:42PM

      by Anonymous Coward on Wednesday October 30 2019, @03:42PM (#913748)

      Made out of aluminum foil, no doubt.