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1500 questions
11
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Method to determine the amount of reflected starlight necessary for an exoplanet to be visible from a given distance/angle?
What is the method to determine the amount of reflected starlight necessary for an exoplanet to be visible from a given distance/angle? (Not from occlusion but actually visible on its own.) Further, how can you quantify this and…
CommaToast
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Why do black holes have jets and accretion disks?
If supermassive black holes possess the gravity required to prevent the escape of photons and other mass particles, why do jets and accretion disks form?
They seem to indicate that something is coming out of the black hole, while mathematics and…
Naftuli Kay
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11
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Finding the solar noon based on longitude and latitude?
Please could someone advise the best method of finding the solar noon based on location?
http://pveducation.org/pvcdrom/properties-of-sunlight/suns-position
The stuff on here has been helpful but I can't figure out what I should be finding out!
LST…
GeorgeTaylor
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11
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What is the long term fate of the gas giants?
If I'm not mistaken, it is believed that the reason for such turbulent weather on the 4 outer gas giant planets is that the internal pressure is so great that it is generating heat, which is causing convection, which causes extreme weather.
Will…
Scottie
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11
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2 answers
Why all the photos from 67p are black and white?
I was wondering why every picture we saw on internet about Rosetta's landing on 67p just black and white ? Is there something i should know ?
John DOE
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What is the reason for high lithium concentrations in Sun-like stars?
In reading the European Space Organisation paper Lithium depletion in solar-like stars: no planet connection (Baumann et al. 2010), several conclusions based on their observations include:
Lithium depletion in Sun-like stars is independent of…
user2449
11
votes
1 answer
Dealing with damp and dew whilst stargazing at night or in the early morning
Sometimes when using my telescope late at night or early in the morning, especially in the more humid of seasons, I notice i sometimes get dew buildup on the lenses.
How can I minimize damp buildup whilst using my telescope?
Simply dabbing away the…
user96
11
votes
1 answer
How can I clean my lenses without causing scratching or damages to the lens surface?
Sometimes you can be trying to observe very faint or very small objects in the sky and it wouldn't pay to have these obscured or marred by a scratch or dust on the lenses.
I keep to good practices and make sure to replace the cap on the lenses when…
user96
11
votes
1 answer
What might cause a planet to have a significant tilt in their orbit?
Most of the planets in our solar system all orbit along the same plane, supposedly because of the almost flat dust clouds that formed the planets.
But some planets, such as the one featured below, have a significant tilt in their orbits that…
user96
11
votes
2 answers
Why does iron consume more energy in the fusion process than it produces?
I understand that once a star starts fusing iron, it's doomed to collapse because iron fusion requires more energy than it releases in the process, allowing the opposing gravity of the star to cause it to collapse.
But why? What makes iron special…
echineve
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What effects do other planets have on the solar system?
For instance, Jupiter is the biggest planet in our solar system. Due to it's gravitational mass it can deflect meteorites and protect Earth from the Oort cloud. While these are positives, the negative effects are that Jupiter can draw comets in…
Darren
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11
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1 answer
Why does Pluto's Orbit underlap Neptune's Orbit
Why does Pluto's Orbit underlap inside of Neptunes Orbit. Clearly Neptunes Orbit is not overlapping on Pluto's. Yet, they fail to maintain the symmetric banding appearance all the other Planets maintain, similar to the quarter mile track you often…
chaonomy
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11
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Crab Nebula Time Period
I've learned that the time period for a rotating neutron star, i.e., a pulsar is very accurate and can be used as an interstellar clock. But according to Walter Lewin's 8.01 Lec 19 on classical mechanics, he says that the rotational time period of…
shortstheory
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11
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2 answers
Why is the Earth's center still hot after millions of years?
Why didn't the center of the earth cool after millions or billions of years? What keeps it hot?
Mario
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11
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4 answers
Why don't Neutron Stars form event horizon?
Trying to compare density of Black Holes and Neutron Stars I came up with the following:
A typical neutron star has a mass between about 1.4 and 3.2 solar masses1[3] (see Chandrasekhar Limit), with a corresponding radius of about 12 km. (...)…
SF.
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