Starship Asterisk*

"Even so, the strong zodiacal light was a pleasant surprise. "
I have never seen the wedge-shaped zodiacal light with the moon present in the sky. Again, APOD is showing photoshopped, quasi-possible images for aesthetic, not astronomic.

I've ridden, in 35 years, 173,200 km. So, another 40 years...

This kinds of artificial photoshopped images would never be needed if every single astro photo comes with an angular scale. The reason they don't is to accommodate people's revulsion to number, and people's laziness from making their own comparison. It’s more than that. Our brains are just more wir...

This is just silly.

This kinds of artificial photoshopped images would never be needed if every single astro photo comes with an angular scale. The reason they don't is to accommodate people's revulsion to number, and people's laziness from making their own comparison.

"astronomers are able to use cosmological time-slowing to help measure vast distances in the universe." Curiously the link provided in the sentence goes to wiki page that describes special relativistic time dilation, whereas the intention is about cosmological time dilation, a different, b...

A refreshingly stark image that clearly contrasts the albedo of Venus (0.75) vs the moon (0.12).
(APOD is suffused with so many photoshopped, cut-and-paste, "enhanced", and physically impossible images that belong on facebook, not on an astronomy site.)

I'll have to dig into my old E&M and MHD textbooks to understand from first-principle how magnetic field lines can stretch 100's of kiloparsecs...

Christ, this makes three APOD in a row on one launch. This is astronomy as a Twinkie is food.
Who runs this website?

Are we looking 'down' on a plane of debris based on rotation of the star, or are we looking at a sphere of debris and just see the thicker edges based on our perspective. Great photo. If you want to learn how we model this nebula from the observations, see: http://iopscience.iop.org/article/10.1086...

The APOD explanation makes this object more mysterious than it is. Much is known about it:

https://alma-telescope.jp/en/news/mt-an ... th_a_twist

and the Nature article:

https://www.nature.com/articles/s41550-017-0060

It just so happened that yesterday I started to re-read Imperial Earth, by Clarke...

Digital imaging is convenience but looking at the raw image with the awful digital artifacts makes me long for the gas-hypered Kodak Technical Pan days...

Well, I was being provocative, and Chris either fell for bit, or (more likely) called my bluff! But I do still feel that an even half reusable launch rocket is a step towards a truly space faring culture. After all, if we could find evidence of life elsewhere, unless future technologies can transpo...

Please, no more SpaceX stunts on APOD. Musk's SpaceX is business, not science, orientated. Keep this site's postings to its name sake, astronomy.

Composite images such as this one, even if they disclose themselves as such, should have no place on this site. Science is based on information with no distortion, embellishment, or exaggeration. Constructed and photoshopped images belong on movie posters.

The days when you see not one person in a small group messing with their phones...

this almost looks more like a 2-d histogram of light dots based on population density than an image composite. almost every 'light pixel' have no variation in size, color or intensity. how much and what kind of post-processing has been done? edit: found the source image from NOAA: the 6 MB image exp...

I do hope that this is the last APOD post on the SST. How did we, as a nation, delude ourselves into accepting, continuing, and now glorifying a transportation system that operated with a 1.5% hull-loss rate? Why haven't we call it out for what it was: an abject failure of design and vision that twi...

See chapter 27 of Gravitation , or a short exercise here: http://www.astro.ufl.edu/~guzman/ast7939/projects/project01.html Cosmological curvature almost by definition can't be measured locally--it is dependent on the energy density of the universe and the cosmological constant. In principal you cou...

See chapter 27 of Gravitation , or a short exercise here: http://www.astro.ufl.edu/~guzman/ast7939/projects/project01.html Cosmological curvature almost by definition can't be measured locally--it is dependent on the energy density of the universe and the cosmological constant. In principal you coul...

If you are thinking of LISA, that is a mission for gravity wave detection (unless there is a component of the mission I am not aware of). No, not LISA, or any of the space-based gravity wave missions. The mission (I don't recall the name off-hand, or how far it got into the proposal process) was sp...

Um, my tensor calculus is nowaday a little rusty but I think cosmological space curvature effects can't be measure around the solar neighborhood, you'd be swamp by local gravitational noise from the sun and planets. The local gravitational field is a source of signal that has to be compensated for,...

It would seem to me that Finite but unbounded would be untestable at least to the limits of current technology. Using the 2d model in a 3d reference frame would essentially say that we could in fact travel in any 1 of 3 spacial directions and eventually wind up back here. How could this hypothesis ...

No more opinion on ID, please! Can someone elucidate on the protein-folding, the entropy of molecular machines and the helicase motor mechanism instead?