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1500 questions
17
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Orbital velocity of a planet - why is my calculation off by about 10%?
I am not sure if I am doing something wrong, or misunderstanding Reider and Kenworthy (2016).
I'm just trying to reproduce the orbital velocities listed in Table 1. The second paragraph of Section II list a mass of the primary and semi-major axis…
uhoh
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17
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1 answer
How much clearer are stars in earths orbit?
As a child I remember my parents taking camping in California, and upon stepping out of the car I was awestruck at how thick the Milky Way galaxy was and at the number of stars everywhere. I've always wondered how much clearer it could get. What…
Paul
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17
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3 answers
Does the moon have days?
As like Earth, does the moon have a day (24 hours). If it has, how many hours are in a moon day?.
RANSARA009
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17
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1 answer
Meteor traveling through atmosphere without hitting Earth
Is it possible (however unlikely) to have a meteorite miss Earth so narrowly and at such flat angle that it would enter atmosphere, travel few (dozens, hundreds, thousands?) kilometers getting as close as few kilometers to the ground without hitting…
Lope
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17
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1 answer
How is it known that Callisto has no core?
My Astronomy book claims that scientists have discovered that Callisto, a moon of Jupiter, has no hot inner core. In fact, it says, Callisto has a core much like the nucleus of a comet.
Is this still accepted theory, and how was this information…
user19
17
votes
1 answer
Any possibility for life on moons of planets in our Solar System
We all focused on our moon, to find water or life, or any thing related to life. But my question is, is there any chance for life in moons of other planets in our solar system, others have too many moons....
ReNiSh AR
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17
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4 answers
What is the difference between our time and space time?
I am trying to understand the phenomenon of space-time. But, everything on internet seems to be too complicated for me since I do not have a background in physics. Can anyone give me simple explanations for the following:
What is the difference…
Asadullah Ali
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17
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1 answer
What would the Sun be like if nuclear reactions could not proceed via quantum tunneling?
Without quantum tunneling our Sun wouldn't be hot or massive enough to produce the energy it does at the moment. So what would have been the temperature or mass of our Sun without quantum tunneling of protons to maintain the same energy we receive…
Marijn
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17
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1 answer
Are astronomers researching or trying to find signs of worm holes?
In many movies and in the popular culture wormholes are often referenced, as well as "faster than light travel", which seems almost to be the same thing, is possible.
Are astronomers seriously considering and researching this phenomenon? What could…
bogen
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17
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1 answer
Do star remnants actually burn?
As we know, some stars can fuse heavy elements to produce carbon and oxygen after using up hydrogen if they are massive, and the remnant of stars are usually hot, my question is, if a star fuse to produce carbon and oxygen, does it also burn to…
Gstestso
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17
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2 answers
Why can we sometimes see the moon during the day?
At some points in the year, the moon at my location can be clearly visible during the day. Why is this?
If it is any help, I live in Alberta, Canada.
aman207
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17
votes
1 answer
Is the Sun really a medium size star?
It is often said that the Sun is a medium size, or even dim star. Is this true?
According to this list of stars within 21 light years, there are, out of the closest 121 stars, only six brighter than the Sun. This means that the Sun is in the top 6%.…
SE - stop firing the good guys
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17
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3 answers
On (minuscule) dark matter production in supernovae
It is believed that dark matter is made of particles, which interact with matter only weakly and gravitationally. One common candidate for dark matter are so called WIMPs. WIMPs, specifically, are heavy and may be their own antiparticles.
And as any…
Alexey Bobrick
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17
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2 answers
Open problems in astronomy that an amateur (with a PhD in some other field) would have a chance of solving?
What are some open problems in astronomy that an amateur would have a chance of solving? Suppose the amateur has a PhD in some other field, owns a basic telescope, a set of filters, diffraction gratings, cameras, and happens to know a lot about…
eclipse
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17
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4 answers
How would we detect an Earth doppelganger planet?
With our current technology, or technology available in the near future (up to 2025), how would we detect a planet exactly like our own, and how close would it have to be to be detectable?
Which methods thus far have proven the most effective for…
Jordan
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