Starship Asterisk*

I am wondering whether sunlight being predominantly yellow-green has something to do with chlorophyll having green colour as well. It doesn’t. It is not to a plant’s advantage to reflect away the predominant wavelengths of its energy source, so the colors are probably just a coincidence. Most plant...

If this is intended to show what a flyover would look like, then why the vertical exaggeration, and why the contrived star field? In fact, this is not what a flyover would look like. Other than artistic purposes and awe factor, which work, the star field is likely there because it is expected to be...

If this is intended to show what a flyover would look like, then why the vertical exaggeration, and why the contrived star field? In fact, this is not what a flyover would look like.

starsurfer wrote:I didn't know the moon also exhibited a green flash. Are they partly due to airglow?

I would expect that it's due to the same refractive dispersion than causes the solar green flash. Airglow wouldn't affect such a localized area, and wouldn't be discernible during sunset anyway.

Another obvious difference is that the Sun appears flattened from Earth, due to differential atmospheric refraction, but not from Mars. Mars' thinner atmosphere must have a considerably smaller index of refraction.

6) Dependable . For many (all?) of us in the northern hemisphere, the Big Dipper never sets, and so it is visible in a dark sky all year round. That makes it a dependable and trustworthy companion. Definitely not all of us. Alkaid's declination is +49 deg 19', so it sets for anyone south of about 4...

Ron-Astro Pharmacist wrote:

Big Dipper Distance.jpg

If VegaStar portrayed the stars as if they were all the same distance from us, this would explain why Alkaid is so much brighter than the other stars. But there is no information posted on how the image was maide.

They most likely were marking a hundred years since “sailing the ocean blue.” Columbus was probably happier that the Earth turned out to be: Sphere.jpg rather than: Flat Surface.jpg No, Columbus was probably happier that America happened to exist. By 1492, all educated people knew that the Earth is...

I believe this is the first time in 15 years that I've seen verification that Chris is wrong. Not bad. Shall we shoot for another 15?

Sorry but a little 101 question here- I don't seem to see how this Nebula got its name the Pelican Nebula? Can anyone offer any light on this? You’re not looking at the whole nebula. The second Pelican Nebula link in the description links to other views of this nebula. Today's APOD is of a small se...

You have to take a look at the link to the original photograph. The APOD version has crippling JPEG artifacts. At first I mistook Mars for an artifact.

When I saw the conjunction IRL, it took me a couple of minutes before I could even see Mars.

If M104 is only 28 million light years away, how can it be part of the Virgo Cluster?

One of the brightest celestial sources visible to radio telescopes, at 600 million light-years distant Cygnus A is the closest powerful radio galaxy. Centaurus A is much closer than 600 million light years, and its radio jets are longer than 300,000 light years . Is Centaurus A not considered a “po...

I cannot make out the tail in my telescope. I can make out some assymetry in the coma; there seems to be a dark triangular wedge in one direction. I did not make a note of which direction the wedge was in. My telescope is 200 mm. I'm not sure of the NELM from my yard. It was about 5 a few years ago,...

That brings up a very good point. If a collision occurred something had to hit it. If a split occurred it could be the striking object (asteroid or comet) reconnecting to a part of the original comet, the two pieces reconnecting or some other three-way scenario. Either way – what's left is an odd d...

I am curious too about the terminal velocity, and weight, but I am too lazy to search the formulas and compute. Anyway, I assume that not only the velocity matters, but weight too, because if your weight is there few grams, sudden stop will be less strong than falling here from a chair. Empirically...

Does anybody know what player the latest VIMEO video "Wanderers" uses? Is it Flash? It refuses to play on my Linux system so I might have to search for an appropriate plugin. My system is openSUSE 13.1. I'm using Firefox 33.0 with the latest GNU/Linux version of Flash, Cisco OpenH264, and...

I think I can spot the Triangulum Pinwheel Galaxy (M33) as well, to the upper right of M31. It's a little farther away from beta Andromedae than I expected, but that's probably just camera distortion.

Nitpicker wrote:Nice image, but Mars was not near its closest approach to Earth last month.

This error stuck out like a sore thumb when I read the description. Is it going to be corrected?

stardog wrote:From the view we have of M81, does it look to anyone else as if the upper right section is higher than the nucleus and is being swept up and away to the left?

Given the absence of any real depth perception data in that regard, I'm going to assume that anything my brain computes is spurious.

Renato wrote:Are we looking at the Galaxy from the top or from the bottom? It is turning clockwise in any case.

What do you mean by “top” or “bottom”?

I’m tempted to remark that APOD has fallen for CNN Syndrome: “We Bring You the News Before It Happens.” At least today’s graphic displays useful information. According to ESA’s Web site, Philae should be landing as I’m posting this, but no word yet. CORRECTION. I must have visited the page mere seco...

I'm surprised no one has mentioned M78, peeking in from the lower left corner of the image. M78 is the lonely one out in Orion; it must surely know how it feels to be M92.

Orion consists of 7 stars, so the opening line should have read "The belt of Orion holds much more than three stars in a row." Time to put on my pedantic hat. Orion consists of a whole lot more than 7 stars. Orion is a mathematically defined wedge of the universe, which contains dozens of...

Oh noes! HAARP is now turning the clouds colors!