# Tag Info

47

Tidal forces generated are proportional to $m/r^3$, where $m$ is the mass of the Earth satellite and $r$ is the semi-major axis (we assume circular orbits for simplicity). The derivation of this relationship is performed nicely by Butikov. So $m_m/r_m^3 = m_c/r_c^3$, where $m_m \approx 7.3 \times 10^{22} \rm\, kg$ is the mass of the Moon, $m_c \approx 9.1 \... 22 As is nicely put on the Wikipedia page about tidal forces, the tidal force is given by $$T=Gm\frac{2r}{d^3}$$ where$T$is the tidal force (see below),$G=6.67\cdot 10^{-11}\rm\,\frac{m^3}{kg s^2}$is the gravitational constant,$r$is the radius of the Earth, and$d$is the distance between the centers of the two objects. This is not force in correct sense (... 8 Ceres is 2.76 AU away from the sun, so the sunlight is seven times weaker. That is comparable to the levels of illumination 30 minutes before sunset on Earth, so you are not going to have any problem seeing the surface. The albedo of Ceres is quite low, comparable to worn asphalt. But it is still easy to see it. 8 According to the Wikipedia page linked by @BowlOfRed, they're ice and/or salt. a material with a high level of reflection, and [the scientists] suggested ice and salt as possibilities. ... On 9 December 2015, scientists reported that the bright spots on Ceres may be related to a type of salt, particularly a form of brine containing hydrated ... 7 It can't cause tides of the same strength Though you could have Ceres exert the same force on the ocean it has to be at a much smaller orbit. A smaller orbit means a shorter orbital period. This means that the Ceres tides can't be same as the current ones. To calculate the wanted equations, we need to use sidereal periods: The Earth rotates once every 23.935 ... 6 As of March 6, 2015, Dawn has entered orbit around Ceres. But it's really so far only "captured by Ceres' gravitational pull". Then, it was still 61,000 km from Ceres. It's slowly spiraling down into an orbit that JPL's Dawn Journal calls "RC3", which will be 13,500 km above Ceres. This orbit will last 15 days per revolution. It will take about 15 ... 5 Several papers with data from the Dawn spacecraft have just been published. Among them, Fresh emplacement of hydrated sodium chloride on Ceres from ascending salty fluids focuses on the composition of these bright deposits called faculae. It shows that the spectral data of some faculae are best fit by a mixture of ammonium chloride (NH$_4$Cl), natrite (Na$_2\$...

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OK, I did a bit of research on this. The LA Times article you quoted says something a little bit useful. While the scientists aren’t sure exactly what the compounds are, the fingerprint is characteristic of material containing carbon-hydrogen bonds, and may include components like methyl and methylene. Methyl means a carbon with at least 3 hydrogen ...

5

Inner. The entire asteroid belt is in the Inner Solar System (now). The definition of "Inner" vs. "Outer" is non-arbitrary, based on the current "frost line", approx. 5 a.u. radius. https://en.wikipedia.org/wiki/Frost_line_%28astrophysics%29 https://en.wikipedia.org/wiki/Solar_System#Inner_Solar_System

3

Five years have passed, and several papers have been published about this. The latest, Neesemann et al. (2019), compiles previous results and propose a new age estimate. Or rather estimates, because dating such object is tricky! It depends on which model you use (lunar-derived chronology model versus asteroid-derived chronology model, or ADM), and on which ...

2

I'm inclined to say no (and footnote, I realize Wikipedia isn't a good source for scientific proof as it's not always right, but I'm using it more to demonstrate a point than than use it as an authoritative definition). Wikipedia: A terrestrial planet, telluric planet or rocky planet is a planet that is composed primarily of silicate rocks or ...

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Comments converted to community wiki Ceres' density (2.08 g/cc) suggests it has abundant water/ice below its presumably mostly dry surface. That and the shiny spot (salts left after subsurface water has sublimated) suggests it wouldn't too difficult. Low gravity, keep the dig in shade to prevent the ice from sublimating in direct sunlight. We could not do ...

2

It seems not yet. The non-uniform density of craters seen on Ceres is still under investigation. From the abstracts of those papers, they're still working on trying to date the ejecta material from that crater, and trying to understand the resurfacing that appears to be going on.

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How did the measured diameter of Ceres evolve over time? Which astronomers attempted to measure the diameter of Ceres, and what values did they find? Background If astronomers can see an object as a disc instead of point of light, they can measure the apparent diameter of the disc. For example, they can have thin wires stretched across the telescope at ...

1

The details are not known for certain, however it is generally thought to have a rocky core, formed of silicates (aluminium and magnesium silicate for example) and a large mantle of water ice, perhaps 50% by volume, 25% by mass. The surface crust is formed of various carbonaceous and iron minerals: siderite, dolomite, cronstedtite. There may be a small iron ...

1

How they have concluded that there could b.e a subterranean ocean on Ceres is by Spectralscopy. Spectral Signature can be summarised to like this: Different elements emit different emission spectra when they are excited because each type of element has a unique energy shell or energy level system. Each element has a different set of emission colors because ...

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