Crater Eratosthenes in colour with the Moon 22d and 15h old (Niall MacNeill)

Contains: Solar system body or event

Crater Eratosthenes in colour with the Moon 22d and 15h old

Acquisition type: Lucky imaging

Crater Eratosthenes in colour with the Moon 22d and 15h old

Acquisition type: Lucky imaging

I imaged the wonderful crater Eratosthenes with the waning half full moon showing it in beautiful relief. The seeing was good and it was interesting to see that the RGB image is superior to that acquired in NIR (642nm BP). In fact I tried the NIR image as Luminance but it detracted somewhat. I love the colours that have come through with the western limb a distinctly blue-grey compared to the redder hue of the terrain further west. Maybe since terrain comes from terre (Earth) I should call it lunain :-). Eratosthenes is at the western terminus of the Montes Apenninus mountain range, some of which can be seen arching up and to the right. It is 59kms in diameter and relatively deep at 3.6kms. It is overlain by rays, which can be seen clearly at the upper left, from the prominent but younger crater Copernicus to the south-west, although it lacks a ray system itself. If it had any they have been weathered away in the 3.2 billion years since the impact which formed it. However, there are deep furrows seemingly emanating from the crater at upper left. The central peak of the carter is prominently displayed as is its somewhat pockmarked floor.

I recently read the account of the Greek astronomer Eratosthenes of Cyrene and how he cleverly determined the diameter of the Earth in about 240BC, by observing the length of the shadow of a vertical rod in Alexandria at the same time when the Sun was directly overhead at the summer solstice in Syene (modern Aswan, Egypt), when sunlight lit the bottom of a deep well. He used trigonometry to calculate the diameter of the Earth with an error of no more than 10-15%.

Please note: The following tables are updated every 24 hours.

Distribution of astrophotographers

This table shows the number of distinct astrophotographers who have been assigned and IOTD/TP award compared to the total number of images awarded.
	Distinct awarded users	Total awarded images
Image of the day
Top picks
Top pick nominations

Distribution of subject types

This table shows the distribution of awards per subject type, compared to the popularity of images of that subject type.
	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

Distribution of data sources

This table shows the distribution of awards per data source, compared to the popularity of images acquired from that data source.
	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

The “AstroBin Image of the Day and Top Picks”, or IOTD/TP, is a long-running system to promote beautiful, interesting, peculiar, or otherwise amazing astrophotographs, with a focus on technical excellence. Learn more.

Submitted The date and time when you submitted this image for IOTD/TP consideration.	...
Views by Submitters (available since September 19th, 2023) Every image is assigned to 50% of available Submitters. In the event that at least 80% of them don't view the image before its time in the IOTD/TP process expires, it's assigned to the other 50% of Submitters and the process begins anew.
Promotions by Submitters When 3 distinct Submitters promote the image, it moves on to the next stage of the process: evaluation for Top Pick status. This requirement, in addition to anonymization of images and distribution to only a subset of them, prevents biases and ensures that the best images are selected.
Promotions by Reviewers When 3 distinct Reviewers promote the image, it moves on to the next stage of the process: evaluation for IOTD status.
Early dismissal Staff members have a lot of images to inspect on a daily basis, and they can dismiss images if they believe they don't meet the requirements for IOTD/TP selection. If an image is dismissed 5 times, it's removed from the process. This streamlines the process and ensures that any bias present in promotions could be overruled by other staff members.

Status	n/a
Started	n/a
Astrometry.net job	n/a
PixInsight job	n/a
PixInsight queue size	n/a
PixInsight stage	n/a

Image Index:

Contribution Index (beta):

Crater Eratosthenes in colour with the Moon 22d and 15h old

Crater Eratosthenes in colour with the Moon 22d and 15h old

Equipment

Acquisition details

Description

Comments

Histogram

		...
You have no new notifications.

Image Index:

Contribution Index (beta):

Crater Eratosthenes in colour with the Moon 22d and 15h old

Crater Eratosthenes in colour with the Moon 22d and 15h old

Equipment

Acquisition details

Description

Comments

Histogram

Notifications

AstroBin is in READ ONLY mode

Sorry :-(

Sorry :-(

Sorry :-(

Are you really sure?

Warning!

Warning!

Are you sure?

Report abuse

Slideshow settings

IOTD/TP stats (last [x] days)

Distribution of astrophotographers

Distribution of subject types

Distribution of data sources

Sorry

Sorry

Share

Upload new revision

Upload uncompressed source (XISF/FITS/PSD/TIFF)

Delete image and all its revisions?

Delete original image?

Delete all other versions?

Delete all revisions?

IOTD/TP stats

The following people like this image

The following people bookmarked this image

Warning

Flag malfunctioning thumbnails

Contains

Remove yourself as a collaborator

Plate-solving information