Skip to content
Vatican Observatory
  • About
    • Overview
    • Team
    • FAQ
  • Telescopes
    • Overview
    • Telescope Images
  • Latest
    • Overview
    • Resources
    • Press
    • Audio
    • Video
    • Research
    • Authors
      • FAQs
    • Newsletter
    • Tucson Meteor Cameras
  • Podcast
  • Education
    • Overview
    • Resource Center
    • Image Gallery
    • Summer School
    • Books
    • Software
    • Additional Resources
    • ACME
    • Ambassadors
  • Shop
  • Calendar
  • Support
    • Overview
    • Donate Now
    • Smart Ways to Give
    • Sacred Space Astronomy
      • View Content
    • Fr. Coyne Fundraiser
    • Bequests / Trusts
    • The Foundation
      • Newsletters
      • Annual Reports
  • Press
  • Specola Vaticana
  • Contact
    • Contact
  • About
    • Overview
    • Team
    • FAQ
  • Telescopes
    • Overview
    • Telescope Images
  • Latest
    • Overview
    • Resources
    • Press
    • Audio
    • Video
    • Research
    • Authors
      • FAQs
    • Newsletter
    • Tucson Meteor Cameras
  • Podcast
  • Education
    • Overview
    • Resource Center
    • Image Gallery
    • Summer School
    • Books
    • Software
    • Additional Resources
    • ACME
    • Ambassadors
  • Shop
  • Calendar
  • Support
    • Overview
    • Donate Now
    • Smart Ways to Give
    • Sacred Space Astronomy
      • View Content
    • Fr. Coyne Fundraiser
    • Bequests / Trusts
    • The Foundation
      • Newsletters
      • Annual Reports
  • Press
  • Specola Vaticana
  • Contact
    • Contact

Go Observe Proclus

By Deirdre Kelleghan  |  28 Apr 2021  |  Sacred Space Astronomy

Share:
  • Share on Facebook
  • Share on Twitter
  • Share on LinkedIn
  • Share via Email
This is the rotated view of my drawing of Proclus crater on the moon - soft pastels and conte. 200 mm dob/8mm eyepiece /150X 20:00 UT - 20:45 UT 3/12/2006

Impact crater

This is a drawing I produced back in 2006. It shows the very bright impact crater Proclus with its radiating ejecta rays. That week brought several days of rain which helped clear our atmosphere of dust. This cleansing precipitation subsequently helped to sharpen up my view of Proclus.

Craters with ejecta rays are always attractive to the eye. An impactor that leaves behind an excavated hole while distributing its interior in the form of bright rays makes a forever statement. There are thousands of craters on the moon, but the impact craters with rays bring something unique to the vista. Tycho in particular has rays so long that they visually offer curvature to the lunar orb. Like the fingers of a hand holding the moon in space.

Proclus stood out white and proud with beautiful rays emanating from its rim. Macrobius above it just a faint circular sun-kissed line. The impactor that created Proclus left behind this very distinct crater and a puzzle. Why are there no ejecta rays over the area called Palus Somni? Over the years, there have been several ideas on the subject of the missing rays. Not all as sensible as the clarification below.

Explaination

Recently I was reading an explanation by Charles A Wood. In his book The Modern Moon – a personal view – he makes the point that ‘Palus Somni is simply the ray – excluded zone of the Proclus oblique impact. ‘ He qualifies this by saying

” when the impact angle is less than 15 degrees, the ejecta pattern becomes elongated in the downrange direction, and a ” forbidden zone, ” where no ejecta rays appear, develops in the uprange direction.”

Charles Wood

Imagination

Imagine being present on the moon within the area of Palus Somni during the impact that created Proclus. The comet or asteroid would have flown over your head. The impact perhaps moving the surface under your feet. Hitting the moon so hard that an 18-mile (28km) wide crater was created before you in an instant. Palus Somni, aka The Marsh of Sleep, now edged in the open rays of ejected material. Perhaps to sleep no more.

The unrotated view

  • Proclus crater - 3/12/2006 20:00 UT - 20:45 UT 200 mm dob / 8mm eyepiece /150X Pastel & Conte on black paper
    Proclus crater – 3/12/2006 20:00 UT – 20:45 UT 200 mm dob / 8mm eyepiece /150X Pastel & Conte on black paper

Useful lunar software

Share:
  • Share on Facebook
  • Share on Twitter
  • Share on LinkedIn
  • Share via Email

Sacred Space Astronomy

The Vatican Observatory’s official digital community and online magazine.

Become a Member

Recent Posts

Ask an AI about the History of Astronomy

By Mr. Christopher Graney  |  25 Mar 2023

Skyward by David Levy – March 2023

By David Levy  |  24 Mar 2023

Conjunction of the Moon and the Pleiades – March 25

By Robert Trembley  |  23 Mar 2023  |  Sacred Space Astronomy

The Northern Mountains

By Richard Hill  |  22 Mar 2023  |  Sacred Space Astronomy

Archives

      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • October
      • September
      • August
      • July
      • June
      • May
      • April
      • March
      • February
      • January
      • December
      • November
      • August
      • June
      • March
      • January
      • November
      • October
      • December
      • November
      • April
      • May
      • January
      • December
      • September
      • May
      • March
      • December
      • November
      • February

More Posts by
Deirdre Kelleghan

C/2022 E3 (ZTF) a last view, bye-bye ancient comet. Thanks for the gift

By Deirdre Kelleghan  |  10 Feb 2023  |  Sacred Space Astronomy

A tale of an unexpected comet

By Deirdre Kelleghan  |  1 Feb 2023  |  Sacred Space Astronomy

The Lunar Occultation of Mars 2022

By Deirdre Kelleghan  |  8 Dec 2022  |  Sacred Space Astronomy

Let’s Draw our Moon

By Deirdre Kelleghan  |  6 Dec 2022  |  Sacred Space Astronomy

Deadly Moons aka Смертоносні Місяці

By Deirdre Kelleghan  |  22 Nov 2022  |  Sacred Space Astronomy

Europa

By Deirdre Kelleghan  |  25 Oct 2022  |  Sacred Space Astronomy

View More

Newsletter

Upcoming astronomical events, scientific breakthroughs, philosophical reflections… just a few reasons to subscribe to our newsletter!

Vatican Observatory
  • About
  • Telescopes
  • Latest
  • Podcast
  • Education
  • Shop
  • Calendar
  • Support
  • Press
  • Specola Vaticana
  • Contact
Privacy Policy  |   Cookie Policy  |   Disclosure Statement

Podcast:

  • Apple Podcasts Listen onApple Podcasts
  • Spotify Listen onSpotify
  • Google Podcasts Listen onGoogle Podcasts
  • Stitcher Listen onStitcher
  • Amazon Alexa Listen onAmazon Alexa
  • TuneIn Listen onTuneIn
Made by Longbeard