Starship Asterisk*

Hi DL, Take a look at this Proper Motion Simulator . Click on the "Pleiades proper motion" link. Once you see the stars, immediately press the P key to pause the simulation. Now click the + button at the upper left to advance the simulation 1000 years per click. As you will see, the Pleiad...

Beautiful 24 hour trails. Since Italy is south of the Arctic circle, amazing how the daytime stars came out! Or was March 14 a looong sun eclipse day? :) The APOD description states "this night skyscape was made by combining 230 exposures each 15 seconds long" 230 * 15 = 3450 seconds 3450...

The Triangulum Galaxy has at least an order of magnitude less stars than the Milky Way and two orders of magnitude less than Andromeda. These numbers are hard to grasp when already in this image 10 to 15 million individual stars are visible. Amazingly, running the math, the number stars visible in ...

Thank you for that explanation ChrisKotsiopoulos and congratulations for a beautiful and interesting image. And thank you to APOD for the wonderful site and to those who contribute to the interesting discussions here on the Asterisk forum. And a special thanks to Chris, Art, Ann and the other regula...

I love this APOD. So many beautiful things to see. If you look carefully in the Eagle Nebula you can see the "Pillars of Creation" that were made famous in a well known Hubble image. https://donsroom.com/forumshots/pillars.jpg The Hubble image: http://apod.nasa.gov/apod/ap120722.html Anoth...

It looks like the photographers, "Dan & Cindy Duriscoe", have some explaining to do.. I don't understand. What's to explain? Is there a rule against compositing a photo to create a pleasing image? I followed the link to the website in the credits and did not see any claims about scien...

If they are both visable, what causes the shadow on the moon? Another planet? Thanks Hi Drep, The shadow is caused by the moon itself. The moon is visible because the sun is shining light on it's surface. The sun can only light half of the moon at any given moment and that is the half that is direc...

For reference here is the image from the APOD rotated 90 degrees clockwise:


Don Bush

Starnut, I do not see a reference to time in Mary's post. Her reference to light-years seems to me to be the same as saying "I am miles behind you" or "You are miles ahead of me". I don't really see a problem with that. In any case, both of our responses are pretty far off-topic ...

John,

I'm not positive but It seems to me that the APOD referenced by the "sandy jets" link is referring to dark sand interspersed with CO2 rather than dark sand interspersed with light sand. Or, put another way, the jets are venting CO2 and the CO2 carries sand along with it.

http://antwrp.gsfc.nasa.gov/apod/ap070712.html

The entire point of this APOD is that we are seeing the galaxy "beyond the stars" of our own galaxy.

Good job Steff! I spotted this gadget on Google a couple of days ago and installed it. It works great. I like the fact that clicking on the image description opens the web browser to the APOD page.

Don

The dark cloud is located in NGC1977. A google search on "NGC 1977" will find several images where you can locate the cloud. Here is one from APOD: http://antwrp.gsfc.nasa.gov/apod/ap010722.html The cloud in question is located at the bottom of this image which is rotated 90 degress clockw...