Starship Asterisk*

Chris, I am supremely impressed with your answer. It gives me even more crazy ideas. Some geologists postulated and wrote a book that a near miss for Earth occurred about 11,500 years ago that caused the Great Flood and other related catastrophes. The closeness of it gravity field shifted the Earth'...

Chris Peterson wrote:I believe "melanin enhanced little person" is the acceptable term, these days.

Even though this person is enhanced, this term is still politically incorrect.

DBE

Small Companion to Brown Dwarf Challenges Simple Definition HubbleSite.org: STScI-2010-03 - 2010 Apr 06 As our telescopes grow more powerful, astronomers are uncovering objects that defy conventional wisdom. The latest example is the discovery of a planet-like object circling a brown dwarf. It's th...

It is not clear to me how fluid dynamic effects, self-gravity, and resonances can clear away, for instance, a 1 km orbiting object that may either be midway between Mercury and Venus, or midway between Venus and Earth , or midway between Earth and Mars. I think you are confounding things that happe...

I am not that familiar with all the details of protostars forming in large nebulas. So what are the observed typical distances between these newly formed protostars ?

Doug Ettinger
Pittsburgh, PA

A recent paper presented the discovery of brown dwarfs within nine light-years from Earth that are barely hot enough to bake a potato - its temperature being 125 to 225 degrees Celsius. The smallest spectral class M (red dwarfs) have temperatures less than 3700 K. This places these dwarfs between .0...

The Search for the Sun's Long Lost Siblings Technology Review - 28 April 2010 Astronomers have published the results of the first serious search for stars that were born with the Sun. Some 5 billion years ago, our Sun was born in a cloud of dust and gas, probably along with about 1000 other stars. ...

My concern is not about the affect of T Tauri winds on the planetary formation or planetary orbits. How does the inner and outer solar system disk become evacuated leaving behind only the planets, satellites and minor planetisimals ? The planets form by a combination of fluid dynamic effects and se...

My concern is not about the affect of T Tauri winds on the planetary formation or planetary orbits. How does the inner and outer solar system disk become evacuated leaving behind only the planets, satellites and minor planetisimals ?

Doug Ettinger
Pittsburgh, PA

This is all well. But, I have a difficult time envisioning how the earlier, stronger, solar winds with their radiative pressures were indeed strong enough to push outward from the inner solar system collisional debris even as large as a typical meteorite or a small asteroid. "I'm not aware of ...

1) The Oort Cloud and what supplied the outer solar system with Kuiper Belt objects is still very hypothetical. I don't really understand what "very hypothetical" means. I'd describe it differently. We observe long period comets, and develop a theory that there must be a distant source fo...

Nevertheless, one collision of two major bodies early in the history of the solar system is presently unavoidable in trying to explain the Earth-Moon system. I disagree. The collision theory of formation is certainly the best supported by evidence, which is why it has become so widely accepted. But...

You may find this paper interesting. http://arxiv.org/abs/0912.0181 A collisionless scenario for Uranus tilting It isn't clear that collisions have been an important factor in modifying any planet's orbit or rotation. The only good case for an actual collision is the formation of the Moon (and even...

G'day Dougettinger You may find this paper interesting. http://arxiv.org/abs/0912.0181 A collisionless scenario for Uranus tilting Authors: Gwenaël Boué, Jacques Laskar (Submitted on 1 Dec 2009 (v1), last revised 9 Feb 2010 (this version, v2)) Abstract: The origin of the high inclination of Uranus'...

I thought that the Great Red Spot specifically maintained a fairly constant longitudinal and constant latitudinal location. Please confirm that this thinking is entirely incorrect; and, the GRS does move across Jupiter's surface longitudinally. http://upload.wikimedia.org/wikipedia/commons/a/a3/790...

Intuitively, I prefer the scattered disk (caused by collisions and perturbations over the life of the solar system) idea over the Oort Cloud theory. They aren't actually all that different. The Kuiper belt, scattered disc, and Oort cloud are all components of a broader theory of planetary system fo...

This is an important insight for me. I realize that these storms rotate and do change somewhat in size and shape. But I thought that the Great Red Spot specifically maintained a fairly constant longitudanal and constant latitudunal location. Please confirm that this thinking is entirely incorrect; a...

It is quite apparent that collisions have taken place not only with asteroids and comets but amongst the major celestial bodies in our solar system. The main affects are orbital changes, rotational changes, and spin axes tilts. I am primarily interested, for the moment, in how spin axes tilts are af...

What causes the spots on the surfaces of the outer planets ? Although spots have been observed not only on Jupiter but also Saturn and Neptune. I wish to specifically address the Great Red Spot on Jupiter but my questioning certainly applies to all spots. The normal public is told that these spots r...

I have asked this question in different ways before, but it has been either circumvented or avoided. I only want the straight truth. Can our 80 astronomical unit wide solar system with its various gravity fields within the invariable plane capture dust and gases of IMC's as it passes through them a...

Neuf, thanks for the update. Intuitively, I prefer the scattered disk (caused by collisions and perturbations over the life of the solar system) idea over the Oort Cloud theory. Also, I am deeply troubled by the Nice Theory where Neptune and Uranus cross orbits and migrate outward. As planetary bodi...

Your reply is excellent. It answers so well what I did not know, such as the solar escape velocity falling off quickly after several solar diameters. Thank you.

Doug Ettinger
Pittsburgh, PA

So without the Oort Cloud and its necessary perturbations theorists are in deep trouble. I value inductive reasoning as well as any other good theorist. But, it would be nice to actually prove the cloud's existence.

Doug Ettinger
Pittsburgh, PA

We didn't know about gravity until an apple dropped onto Sir Isaac Newtons noggin. It could have happened, it might have happened but we will never know if it happened for sure. ---------------------------------- <<The Indian astronomer Brahmagupta, in his Brahmasphuta Siddhanta ("The Opening ...

I am not sure what Venus presenting it same face during conjunctions with Earth has to do with this topic. This only tells me that Venus is becoming tidally locked to the Sun. Venus and Earth being in close orbits and then separating is a hypothesis that I have not heard about. Doug Ettinger You ma...