Starship Asterisk*

I wondered if the chart linked from the APOD page might be for a solar eclipse. Since the size of the shadow cast by earth's umbra is greater than the size of the moon then it would cover the entire surface area of the moon. How would it be possible for it to obscure varying degrees of lunar visibi...

Why are there so many craters on the moon and how often do they hit? We don't see as many on other planets do we? About 4 billion years ago, something happened that flung a lot of material into the inner Solar System. This was the Late Heavy Bombardment, which isn't well understood, but may be rela...

Actually gregg07 if you check Iridium flare fits better. Nope, there were no flares, nor even more than one Iridium satellite in the field at the times the images were made. Also, there's nothing to suggest that the light on the hill is a spotlight aimed at the sky. And it's no less likely to have ...

I thought space was darn cold. :lol: Space in the Solar System is pretty bloody hot. In Earth orbit, say where you find the ISS, the temperature is around 1000K. between the planets, it can reach nearly 1 million K. Of course, the particle density is so low that you transfer almost no energy convec...

Well i dont think earth might survive if the sun will become a white drawf soon.. It is possible for the Earth as a planet to survive the process of our Sun becoming a white dwarf. A red giant is tenuous and cool enough that a planet might continue to orbit inside it. However, the Sun will also hav...

But what happens,if our sun dies n become a neutron star..? Will all the gravity be lost? Will all the planets,collapsed n become unarranged? Will we collide with other planets..? Will our planet,be dark forever..? Our sun is not massive enough to become a neutron star. It will eventually become a ...

My latest re run with Guide 8 comes in agreement with MaG's research:- IR35 (#24966) 03.23:24 - 03.23:38 (EEST) IR97 (#24967) 03.32:40 - 03.32:48 " IR5 (#24795) 03.41:54 - 03.42:06 " IR6 (#24794) 03.50:52 - 03.51:25 " IR7 (#24793) 03.59:54 - 04.00:28 " I question these results. ...

IRIDIUM 8 (#24792) 00:40:38h UT (Lowest streak. Slight flare) IRIDIUM 51 (#25262) 00:49:55h UT (Flare) IRIDIUM 7 (#24793) 00:56:05h UT (Small duration flare) IRIDIUM 6 (#24794) 01:06:56h UT (Faint trail) IRIDIUM 5 (#24795) 01:08:21h UT (Top most very faint trail) Unfortunately, these times are not ...

If you look closely you will notice there are more than 5 streaks in the image... they begin near the base of the photo and track toward the upper-left corner... at the point where the three brightest streaks are located they shift direction and begin tracking toward the upper-right corner of the i...

Which is why I posted my lens/filter scratch question. Sometimes the simplest of solutions is probably the most likely. :) As we are all interested in the search for knowledge, I don't think it would be too embarrassing for the author to say, "oopsy, I just took a look, and there are scratches...

1) Check location. I searched: Turkey, than Beynam.. it gives me: Beynam, Turkey WGS84: Lon: +32d53m45.0s Lat: +39d41m21.0s Alt: 1324m 2) Check date and time: Date 12. 8. 2007, time - the best is maybe UTC, so than you must enter 0:15 for beginning and 1 hour span (to 1:15 UTC).. I think you've mad...

I submit: Location Beynam near Ankara, Time: 4:00 - 7:00 local time. and I receive this in Calsky.com: 4:23:26 Iridium 35, -1,9 mag (in Orion) 4:32:45 Iridium 97, -4,7 mag (in Orion, spare satellite, time and mag can be inaccurate) 4:42:04 Iridium 5, -2,6 mag (in Orion) 4:51:19 Iridium 6, +1,2 mag ...

reminds me of this discussion. http://asterisk.apod.com/viewtopic.php?t=249 Yeah, me too. Just like in that case, we've got one or two simple, straightforward possibilities, and a discussion that takes on a life of its own as people try to come up with off-the-wall, crazy theories- many based on a ...

Both the stars and the trees have pretty well defined positions in this photograph, which I think is incompatible with the fact that Earth rotates about 10 degrees around its axis in the term of 40 minutes. The trees look well defined, then the camera was rotating with Earth and the stars should ha...

Where Chris comes up with the idea of stacking is news to me, and not listed about the image. The same image was submitted to Spaceweather.com with the following comment: I took a 100-picture series of 105-second wide angle pictures using a Canon EOS 300D camera at ISO1600 and a 10-22 mm lens at 10...

I'm curious how astronomers go about detecting naturally-occurring stellar lasers. Are they detecting the coherence of the laser light, or simply the strong peak emission frequency in the stellar spectrum? As noted earlier, laser light loses its coherence quickly with distance, so that cannot be us...

What are they? Thoughts? Normally, when you see short streaks through Orion they are geosynchronous satellites. But in this case, the direction of travel is too far off the ecliptic, and the angular speed is too great (assuming each streak was caught in a single 105-second exposure). Supposedly, th...

Wrong wrong wrong Coherence is whenphotons are "in step" and have a definite phase relation. Unrelated to the point you are making. The question I was addressing suggested that the coherence of a laser could be used as a signature of an artificial source. I merely pointed out that coheren...

Seems to me that the more heavily cratered side of Dione should be the trailing side.Right? Dione has about an equal chance of hitting a prograde bit of debris on the leading or trailing edge. But there's bound to be lots of retrograde debris as well, which will selectively hit the leading edge. Al...

Equate potential energy with kinetic energy at the planet's surface, solve for speed, and you get a figure of the order of km/s, which is a lower bound on impact speed (for airless worlds). And no, a planet or large moon can't "sneak up" on asteroids traveling at almost the same velocity ...

Q: I have observed, during my several months here, that the moon does not rise from a predictable spot on the horizon each night. In an urban setting you can't see this, but here I have a clear view of the horizon. One night it rises directly across the lake between two, large, oak trees and the ne...

Ref. todays picture and comment regarding the effect of shining a laser at the galactic centre. Forgetting for the moment the distances and hence time frames involved and given that we, with our limited technology, are able to detect water molecules in distant atmospheres, is it not the case that n...

A suspected isolated black hole was supposedly discovered a few years ago when some astronomers noticed a small star suddenly brightened and then dimmed. It wasn't a white dwarf going nova. I can't remember offhandedly where it was reported. Of course, this claim was questioned, but finding a black...

You can detect a solitary black hole only when one passes in front of a bright background object, such as a star. I don't think there's any case of a black hole being seen as a silhouette. They are just too small, even if one did happen to pass right in front of a star (which itself is unlikely). B...

yes, now i have a clear picture. when they are called "night shining clouds", that is a bit of a misnomer, because they are just as "night-shining" as for instance the moon - they receive their light from the sun, but because they are so very high up in the atmosphere, they can ...