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.
On Astronomy Picture of the Day (APOD) for 3/1/21 there is a picture taken by Hallgrimur P Helgason, showing a great example of pareidolia (the tendency of humans to perceive a pattern that is not there.)
As it isn’t copyright free I’m not displaying it here but this is the link.
It’s a wonderful shimmering green-aura’d image of a flying bird which APOD likens to a phoenix (itself of course non-existent.)
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.
This is an animated sequence from You Tube via Astronomy Picture of the Day for 3/11/20 showing the OSIRIS-REx spacecraft touching – and lifting up part of – the surface of asteroid Bennu.
The plan is to return the sample to Earth for analysis with an eye to determining conditions in the early Solar System and whether the astreroid contains unusual minerals.
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.
A video of Asteroid Bennu, first of all with speeded up spin, then zooming in to a prominent rock on the surface (given the name Simurgh apparently,) as shot from spacecraft OSIRIS-REx shortly to try to land and get a sample of Bennu to bring back to Earth.
It’s still thrilling to me that we as a species can do and see things like this.
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.
