Astronomy

I agree, the dazzling white blotches on Ceres are not likely to be ice, it does not even look like ice.

All star-gazing for me will have to wait until autumn when our night-time returns…

There is an item in the website Space once more raising the possibility of there being an infinite multiple of universes. Or what if the universe is endlessly vast in which there is no big bang? We know now that new stars and so new galaxies are born out of cosmic dust, in nebulae, which throws into doubt the big bang theory of the birth of our universe. It is all too simplistic a view. But now I am into big questions that leave me floundering...

It looks like the time you can view the stars is almost as limited as mine. In the summer when it is warm, there is too much light. In the winter, when it is dark enough, it is too cold. I have to leave my location to view the Milky Way, although I have seen it in Wisconsin and Indiana, neighboring rural states.

The multiverse does seem to be a consequence of there being a big bang. If the universe had a beginning, and eternity is eternal, there must have been many of these events.

The description of Robert Grosseteste's work linked in the Space article you refer to, http://www.space.com/25301-multivers...osseteste.html, makes me think we might be misinterpreting him. The article refers to an "extra reason" Grosseteste had, but I don't know what it was. Today, many think we need a multiverse not just because eternity is eternal and what happened once would happen again, but to get to our universe there must have been a lot of failed universes out there where life could not survive. However, all of these universes may have succeeded in generating life.

I think the big bang is true, because we don't see anything older than 14 billion years in our universe. It is probably more complicated than we are currently aware.

Thanks for the link YesNo, that was it, the Grosseteste article.

The plans that are being made for tunnelling probes seem quite fantastic. This article is an example of that: http://www.space.com/29644-cryobot-t...kly_2015-06-15

It amazes me that there is an ocean there under the ice. I would have thought it would be solid ice all the way down.

We are starting to get more information on Pluto and its moons:

Society for Popular Astronomy [email protected]

TWO CHAOTICALLY TUMBLING PLUTO MOONS

Space Telescope Science Institute (STScI)

A comprehensive analysis of all available Hubble data shows that two of Pluto's moons, Nix and Hydra, are wobbling unpredictably. Scientists believe that the other two small moons, Kerberos and Styx, are probably in a similar situation. Such chaos may arise because the moons are embedded in a dynamically shifting gravitational field caused by the system's two central bodies, Pluto and Charon, orbiting one another. The variable gravitational field induces torques that send the smaller moons tumbling in unpredictable ways. The torques are increased by the fact that the moons are ellipsoidal rather than spherical. Hubble's monitoring of Pluto's four outer moons has also shown that three of them, Nix, Styx, and Hydra, are locked together in a resonance with a precise ratio among their orbital periods. That ties together their motions in a way similar to that of three of Jupiter's large moons. Hubble provides observational evidence that the satellites are also orbiting chaotically. However, that does not necessarily mean that the system is on the brink of flying apart. Astronomers would need to know a lot more about the system before they could determine its long-term fate. Surprisingly, Hubble also found that the moon Kerberos is as dark as charcoal, while the other satellites are as bright as white sand. It was predicted that pollution by dust blasted off the satellites by meteorite impacts should coat all the moons, giving their surfaces a homogeneous look. The New Horizons probe, which will fly by the Pluto-Charon system in July, may help to settle the question of the asphalt-black moon as well as the other oddities uncovered by Hubble. The new discoveries are being used in the planning of the New Horizons observations. The chaos in the Pluto-Charon system may offer insights into how planets orbiting a double star might behave. We are learning that chaos may be a common trait of binary systems, and the Kepler space observatory has found several planetary systems orbiting double stars.

Clues to the Pluto chaos first came when astronomers measured variations in the brightness of the two moons Nix and Hydra, which changed unpredictably. The team analyzed Hubble images of Pluto taken in 2005-2012 and compared the changes in the moons' reflectivity with dynamical models of spinning bodies in complex gravitational fields. Virtually all large moons, as well as small moons in close-in orbits, keep one hemisphere facing their parent planet, as the Moon does to the Earth, so the satellites' rotations are perfectly matched to their orbital periods, as a consequence of gravitational tides between moon and planet. (Hyperion, which orbits Saturn, is the only other Solar System example of chaotic rotation; it is due to the combined gravitational forces of the planet and it largest moon, Titan). Pluto's moons are hypothesized to have formed by a collision between Pluto and another similar-sized body early in the history of the Solar System. Pluto's large companion, Charon, which is almost half the size of Pluto itself, was discovered in 1978. Hubble discovered Nix and Hydra in 2005, Kerberos in 2011, and Styx in 2012. Those little moons, measuring just tens of miles across, were found as part of a search for potential hazards to the New Horizons spacecraft flyby. Pluto and Charon are called a double planet because they orbit about a common centre of gravity that is located in the space between the bodies. Some people regard the Earth--Moon system as a double planet, too, although its centre of gravity falls within the Earth. (Our Moon has 1/80th of the Earth's mass, whereas Charon has 1/8th of Pluto's mass.) A combination of data from Hubble, New Horizons's brief close-up look, and eventually the James Webb space telescope, should lead to increased understanding of the Pluto-Charon system. No ground-based telescope has yet been able to detect the smallest moons.

It is interesting that the smaller moons of Pluto have only recently been discovered and then mainly as research for New Horizons.

Also the idea that Pluto and Charon may be a "double planet", or probably better put double dwarf planet, is because the center of gravity is outside both Pluto and Charon unlike the Earth-Moon center of gravity which is inside the Earth.

We know that Saturn's largest moon, Titan, has surface lakes of ethane and methane and there are plans to send a probe to investigate these more closely. Now Jupiter's moon Europa is also known to have sub-surface oceans and there are plans to send a probe there too.

I haven't seen anything new pop up in searches on Ceres. I was hoping there would at least be closer images.

A couple nights ago, I saw the big dipper while I watched the moon set. I check my vision based on how clearly I can see the moon at night. My astigmatism sometimes gives me many images of the moon, most of them blurry.

Ceres Google search iso'd to last 1 hour: https://www.google.com/search?q=cere...g&ved=0CA8QpwU

Ta ! (short for tarradiddle),
tailor STATELY

Here's an article about Population III stars, the oldest stars, "unpolluted" by atoms besides hydrogen and helium, that I found by running the query you provided, tailor STATELY: https://medium.com/starts-with-a-ban...e-f5385eb4264d

It is 2 weeks to the historic flyby of the Pluto system. The last planet to visit in a half-century of exploring our solar system. New Horizons will pass at high speed between Pluto and Charon. See EarthSky.

The animation in the video doesn't make it look as if the center of gravity is outside Pluto. I would have expected them to both circle a center outside Pluto.

NASA and New Horizons show what they term "the wobbly dance" of Pluto and Charon. Maybe this is indicative of the centre of gravity being outside Pluto?

Yes, that one does show the center of gravity outside Pluto. I wonder if we would feel dizzy living on such a planet? Probably not. Perhaps the stars would have a retrograde motion as the outer planets do for us.