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Eyeball this Nebula

I found this (copyrighted) image on Astronomy Picture of the Day for 18/1/21.

The text on APOD’s post refers to it as looking like a brain – hence its name, the Medulla Nebula.

To me, though, it looks more like an eyeball – with the optic nerve going off to the right as in the diagram below.


Mountains on Pluto

Remember those days when Pluto was just a blip on a photographic plate, then merely a fuzzy set of dots on a Hubble telescope image?

No more.

Astronomy Picture of the Day for 15/1/21 featured this photo taken by the New Horizons probe 15 minutes after its closest approach to the (dwarf) planet when it was 18,000 kilometres away from the surface.

Some of the mountains on show are comparable in height to the highest on Earth but of course they are not composed of rock but most likely of ice. The plains below them may contain solid nitrogen or carbon dioxide.

Also visible above Pluto’s horizon is its tenuous atmosphere.

Pluto's Mountains

The Hidden Face of Titan

From Astronomy Picture of the Day for 9/1/21 here is a view of Saturn’s moon Tiatn that you would never see if you were somehow be able to be on Saturn itself.

Titan is tide-locked to its primary and so always presents the same face to it. Its reverse side however was however visible to the Cassini probe.

Since Titan has an atmosphere its surface is not seen directly but the fuzziness around its edges – seen against the thick line of Saturn’s rings and the planet itself beyond – shows the atmosphere’s thickness relative to the satellite.

Titan from Cassini

The Sound of Dark Matter?

This is an oddity. From You Tube via Astronomy Picture of the Day for 16/12/20.

It’s a sonified image of the Bullet Cluster with low tones assigned to Dark Matter, mid-range to visible light and higher tones to X-rays.

It may be though that Dark Matter does not exist, as this post from the Daily Galaxy argues.

Collapse of Arecibo Telescope

The Arecibo Telescope was the largest single-dish radio telescope in the world for over 50 years. Among its achievements in Astronomy it has been used to measure the spin of Mercury, map the surface of Venus, discover the first planets outside our Solar System, verify the existence of gravitational radiation and search for extraterrestrial intelligence, but it seems it was first built for military purposes.

While being decommissioned the structure had a total collapse early this month.

The collapse was captured on video:-

UGC 810

What a gem this is. Another from the Hubble telescope via Astronomy Picture of the Day for 18/10/20.

This is galaxy UGC 810. Its odd shape is because it is in collision with UGC 1813 (out of picture below the frame.) Altogether the configuration is known as Arp 273. See previous photo here.

UGC 810

G W Orionis

The Universe is a varied – and at times weird – place.

All of our Solar System’s planets orbit more or less in the same plane – effectively as if on a disc.

G W Orionis is different, showing orbiting material in different planes – maybe because it has three stars at its centre.

This animation is from You Tube via Astronomy Picture of the Day for 29/9/20:-

Where Elements Come From

I just love this.

Then again, as a chemist you would expect me to.

I got to this Periodic Table via Astronomy Picture of the Day (APOD) for 9/8/20. It shows the origins of the chemical elements as percentages of how the total number of each elements’ atoms were formed.

Periodic Table of Elements' Origins

Those parts in blue were formed in the Big Bang or by nuclear fusion in stars, green came from dying low mass stars, pink from cosmic ray fission, yellow from the explosions of massive stars, purple from neutron stars merging, light grey in exploding white dwarf stars.

There are areas of darker gray. The elements these refer to are mostly not found naturally – Technetium (Atomic Number 43,) Promethium (Atomic Number 61) and all the transuranics (Atomic Numbers greater than 92) can be made artificially in particle colliders or nuclear bombs and reactors, though I note that Neptunium (93) and Plutonium (94) seem to be produced by merging neutron stars. All elements with Atomic Numbers greater than 82 are radioactive and so decay away over time which is why the transuranics are not found on Earth and only some atoms of elements 82-92 are.

Quite why the version of this table that appears on APOD also has elements numbered 84-89 plus 91 in dark gray puzzles me a bit.

Butterfly Nebula, NGC 6302

This beautifully detailed photo appeared on Astronomy Picture of the Day for 21/7/20.

It was taken by the Hubble Space Telescope and shows the Butterfly Nebula, NGC 6302, with emissions by iron atoms in red.

Butterfly Nebula, NGC 6302


A naked eye comet can be seen in the sky since the beginning of the month. First observed by the NEOWISE space telescope (and hence named after it) on 27/3/2020, it blossomed in brightness on nearing the Sun and became visible to unaided human eyes in July.

I’ve not observed it myself. It’s been too cloudy when I remembered to look but the photographs have been great – especially the ones with Stonehenge in the foreground.

(Pictures from BBC news website.)


NEOWISE over Stonehenge:-

NEOWISE over Stonehenge

This is a time-lapse video from You Tube of NEOWISE rising over the Adriatic Sea.

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