Starship Asterisk*

Holy cow! I just about fell out of my chair when I saw this (neufer, here's your definitive answer): http://hirise.lpl.arizona.edu/phoenix-descent.php Note, it's not falling into the crater. Foreshortening from the long focal length of HiRISE skews the perspective. From the HiRISE site: "Althou...

Beats the bouncing method by the Rovers. These techniques with the landing thrusters will just help improve future landings (by robots or humans) now that the data this time around from the affects of the atmosphere can be analyzed and new sequences perfected. Great for similar landings on other wo...

They didn't remove it. The picture on the Phoenix site is brightened and contrast enhanced pretty severely so that the parachute is overexposed. If you look close at the APOD, you can still see the texturing behind the lander, and even some faint details of the parachute. These are blown out in the ...

Considering the difficulties the Soviets faced in sending back pictures from Venus 30 years ago Phoenix was not much of an accomplishment .. almost like a walk to the corner store. The technology Phoenis is using for sampling soil seems primitive to me .. I would have thought they could have done i...

Right. The parachute actually detaches before landing. The final descent is thrusters only. Theoretically the wind should blow the parachute and backshell further than the lander because their less dense, but just in case, the lander aims itself slightly upwind. The Phoenix team had a good article a...

I wonder how the Fujiwhara effect will apply here, since Jupiter's storms don't seem to change latitude due to the strong banding of the atmosphere. Arramon, when we look through Titan's atmosphere, it is primarily with radar. There's certain infrared "windows," too, but the view at those ...

BMAONE23 wrote:They look like Volcanic Glass spires that have melted and drooped in the heat.

I'm pretty sure this is the effect the artist was trying to convey. You sometimes can find similar shapes in Hawaii. Solar erosion is very slow, and Gliese 876 is a red dwarf, so it has a relatively weak solar wind.

This isn't material ejected from the star. It's interstellar material being pushed outward by the radiation pressure and stellar wind. This occurs at the heliopause. In the direction of motion, the build-up is usually greatest, creating a bow shock, but that is not the case here, apparently because ...

I figured that old Sol may be a 2nd or 3rd generation star; but never thought of it as being formed from a neutron star collision's debris field. I guess it's building blocks had to come from somewhere! :shock: Could it be that the sun and solar system may have happened to come into the clutter tha...

The flyover basically amounts to eye candy, but the data it was constructed from is not. The rover crew creates 3-D surface models to help navigate the rovers. It gives a much better view of the land and potential routes and science targets than 2-D pictures. It also provides hints about the geologi...

If I'm reading the caption right, not all of the gold in the universe would come from neutron star collisions according to this theory. Some would be due to more "conventional" supernovae, but the amount of gold is apparently higher than theory for this predicts. Orin, our solar system for...

Normally galaxies seem to have a roughly Gaussian distribution radially from the center, as well as at a distance from the ecliptic plane for a given radius. In this case, it seems the latter tendency is the one that breaks down the most. My guess would be it's due to a gravitational interaction wit...

The planets all have slightly different tilts, but even without that, the orbits are out of sync. I suppose the difference is related to what point the planets are in the orbits at the various points in the analema...when they on the "upward" part of their travels versus "downward.&qu...

It's fantastic. It somehow manages to set itself apart from the many other excellent pictures of galaxies and starfields.

Wallpapered!

A light-year is 9.5 x 10^9 km. So the volume of a 1 light-year sphere is 4.5 x 10^29 cubic kilometers. Caution! A light-year is 9.46 trillion kilometers: 1 ly = 9.46 x 10^12 km, and a sphere of radius 1 ly encloses a volume of 3.5 x 10^39 km^3. A 25-solar mass sphere would have a mean density of 1....

I see the dragon from Neverending Story.

I'll bite on neufer's suggestion. The sun has a mass of 2.0 x 10^30 kilograms. A light-year is 9.5 x 10^9 km. So the volume of a 1 light-year sphere is 4.5 x 10^29 cubic kilometers. Our hypothetical 25 solar mass Bok globule then has a density of about 110 kilogram per cubic kilometer. Easier to vis...

Sputnick, I respectfully disagree. Compositing can be abused, but when done properly, it adds a lot beyond the original. Just a day earlier was a beautiful panorama. These are usually made by stictching a mosaic together, which is a form of composite: http://antwrp.gsfc.nasa.gov/apod/ap080503.html B...

http://apod.nasa.gov/apod/ap060606.html NGC 6164/NGC 6165 (each side has its own ref. no. in NGC.) is an emission nebula . At the center is star HD 148937. Although it is also mentioned in some older planetary nebula catalogs (Hen, PK, ARO, VV), a note on SIMBAD says it is not a PN. (My first thoug...

If you're talking about the compact green and blue cloud cloud with a purplish star embedded at it's center, it appears to be a planetary nebula.

I find it interesting that these two galaxies are so intact and undistorted, yet some of the past APOD's of galactic collisions or mergers show major stretching and deformation. I suppose it could be simply a factor of their relative velocities, where slower mergers allow more time for galaxies to p...

The putative supermassive black hole at the center of our Milky Way is much too low in mass to exert gravitational influence on stars outside its nearby vicinity. So, if the Milky Way (and other spiral galaxies) are not whirling around a central black hole, then what are they whirling around? Why a...

I heard they are building a new telescope, to replace HUBBLE. Hope they test the optics first for it will be a stunning collection of images, I am sure. They are working on the Kepler; to be launched next year, but I don't think it is to replace Hubble. Rather I believe it is a planet hunter. :) ht...

This image might help place the coasts: http://flightaware.com/live/ This is realtime minus about 5 minutes. The link right below the animation shows the last 24 hours in similar time lapse to the APOD. It's pretty cool how you can see the common routes and even pick out a few hubs with radiating sp...

I don't think it's true, due partially to the fact that I've never heard it before, and partially due to my understanding of the way the eye works. It's true that we can't spatially resolve stars as discs, but even as point sources they still stimulate the eye, and the eye has it's own imperfections...