3
votes
1answer
52 views

What places on Pluto and Charon are facing each other?

What places on Pluto and Charon are facing each other? Are Pluto and Charon perfectly tidally locked, or is there a slow rotation over time? And how long after formation should they have become ...
1
vote
1answer
36 views

Relationship between the Casimir force and dark energy

This is related to another question I asked. Might we actually be observing dark energy when we do experiments that verify the Casimir effect?
0
votes
1answer
49 views

How to get from the earth to another planet/ the moon? What happens on the way? [closed]

I have a problem explaining for my students how to get from the earth to the moon? Is there someone who can give a good explanation? I Think these are words that might be included. Escape velocity, ...
0
votes
2answers
88 views

Why can falling stars only be seen moving down towards horizon not up away from horizon?

Are falling stars as we know only just space debris entering and burning up in the atmosphere and not a star at all?
4
votes
1answer
88 views

Telescope collimation issue

Recently I purchase Chinese 8 inch reflector telescope from local store. When I observing starts and planets I've been having trouble getting really sharp image from this telescope. I observe Venus ...
0
votes
1answer
67 views

How much heat is generated from waxing and waning of reflected radiation from the Sun?

According to this article, the greatest cause of global warming would be from the waxing and waning of reflected radiation from the Sun. (Placing carbon emissions at 10-20%) So really, how much heat ...
2
votes
0answers
34 views

Moving from computerised to normal amateur telescope?

A few years ago I purchased a Celestron Nexstar 130 SLT computerised telescope thinking that it would be a perfect to get me into astronomy. The issue is the computer doesn't work at all and manually ...
3
votes
1answer
775 views

How many constellations in the Zodiac?

The astronomical zodiac contains a bunch of constellations along the ecliptic. Some sources say there are 13 constellations in the astronomical zodiac. Other sources claim there are 12. According ...
1
vote
0answers
20 views

I'm making a presentation for a planetarium, any topic ideas? [closed]

As part of a project I'm making a presentation that will be displayed on my university planetarium dome, using the Nightshade software. I'm looking for topic ideas... The subject I thought about ...
2
votes
2answers
59 views

Calculate Local Sidereal Time

I am trying to follow this guide and move to a programming language but I have doubts. What means the strings A, B and C in this manual? ...
3
votes
1answer
51 views

How is the Lithium Depletion Boundary used to determine the age of a stellar cluster?

According to my understanding of Soderblom et al. (2014), lithium ages of stars are determined as follows: Determine lithium abundance from equivalent width measurement of Li$_{\mathrm{I}}$ ...
3
votes
1answer
42 views

How do proto-planetary nebulae gain momentum?

currently I am curious about proto-planetary nebulae. At first I was curious about how planets spin but I read in a couple of articles that they got their spin from when they were in a proto-planetary ...
1
vote
1answer
48 views

Realistic space environments [closed]

You've seen it in all kinds of science fiction, be it books, games, movies, and such. Space is depicted all sorts of ways, with asteroids far too close together, nebula thick enough to hide in and ...
3
votes
0answers
43 views

What's the bleeding-edge model for how Population III stars are born and evolve?

I'm trying to do a brief literature review to find out what the best current models for population III stellar evolution are. I was hoping that someone with more expertise in the area could perhaps ...
1
vote
2answers
300 views

What would happen if a rocket traveling at speed of light would collide with a planet (like earth)? [closed]

Let's assume it is possible for a spacecraft to travel at the speed of light (I've read the interstellar book by Kip Thorne, apparently this is theoretically possible if you swing around two black ...
2
votes
0answers
54 views

How special is the Solar system compared with other planetary systems? [closed]

For example: Most planets have circular orbit What else?
3
votes
1answer
101 views

Does liquid water on Mars means life?

We need to figure if liquid water is present throughout a Mars year, and how long the planet has been at its current distance from Sun. That will give us the length of time that liquid water has been ...
5
votes
2answers
298 views

What would happen if we stepped on the Sun?

I mean in intrinsic detail. What would happen to our bodies besides "burst into flames"?
1
vote
1answer
53 views

Is liquid water on Mars such a big leap compared with ice?

I thought we have found bacteria or other kinds of life on Mars. Now it is liquid water. Is there such a big difference between liquid water and iced water?
6
votes
3answers
294 views

Could there be dark matter black holes?

Could dark matter compress and form black holes? Since dark matter is even more abundant than normal matter, a dark matter black hole should not be rare...right?
4
votes
2answers
142 views

Are planets moving away from the sun?

I saw on the tv show Through the Wormhole (hosted by Morgan Freeman) that the planets in our solar system have been continuously moving away from the sun for millions of years. however, when I try to ...
5
votes
1answer
89 views

What is the brightest star (relative magnitude) in M31?

I am wondering what the brightest individual star is in M31, the Andromeda Galaxy. Specifically, brightest as seen from Earth (so relative magnitude).
2
votes
1answer
43 views

Estimation of average rock and asteroid mass associated with different stars

There is a lot of information on different star types and compositions. Can we make estimates of the total mass of rock, ice, and non stellar matter that orbits stars based on star evolution models? ...
6
votes
1answer
71 views

What are the most valuable meteorites and asteroids in terms of precious metals?

There were some suggestions that asteroids could one day be mined for precious metals. I have found an outdated study that says that some siderites contain as much as 0.001% of gold: ...
5
votes
1answer
169 views

How can one explain the apparent motion of the Sun from a heliocentric point of view?

From a horizontal frame of reference, the path of the Sun looks like a part of a circle in a tilted plane, as shown in this picture: ...
2
votes
1answer
65 views

Can all areas on Earth experience a total solar eclipse?

A solar eclipse only puts part of Earth at a time in shadow, so I'm not talking about a solar eclipse that casts a shadow over all of Earth. What I mean is: are there any areas on Earth where, no ...
2
votes
1answer
95 views

What light source can cause a shadow of a cloud onto the next cloud above?

Scenario- -Time & Environment-11:00pm Super Moon small town population 40,000 in Central Ca. -Nearest body of water is 80 miles away 4 small lakes of about 1 mile in diameter. -Pacific Ocean is ...
3
votes
1answer
129 views

How to calculate the heliocentric velocity of an object?

My task is to calculate the heliocentric velocity of an object to correct for wavelength in a spectrum. I have the RA, Dec and observation date, and I know that the NED velocity correction ...
1
vote
1answer
114 views

Is our Universe a hologram? [closed]

I watched a documentary where I heard some very strange theories that are difficult for me to comprehend. It is even difficult for me to explain what I heard. "Objects that fall into a black hole ...
3
votes
1answer
45 views

Gaia: What is the difference between CCDs used for astrometry, photometry, and spectroscopy?

My knowledge of CCDs is that these are sensors which collect photoelectrons. That's about it. What is a difference between CCDs used for astrometry, spectroscopy, and photometry? As an example, each ...
2
votes
1answer
129 views

Can we draw a min(distance) and max(mass) relation based on current observation data of nearby astronomical objects within several parcsecs?

The data precision now can exclude a >>$1M_{\odot}$ black hole, which has a , say 10000 year orbital period with our sun? We can draw a two dimensional diagram(Mass VS. distance) to show the region ...
4
votes
2answers
70 views

September 26 twelve hours sunrise to sunset?

I noticed in today's newspaper (Boston Globe, September 26) that sunrise and sunset were both at 6:25. That's the twelve hour day I'd have expected at the equinox. (Please retag if there's a better ...
3
votes
3answers
173 views

Less stars in the night, compared to 15-20 years back

I am not sure if my question is true or not. But this is what I observe regularly. When I was young and when I look at the sky, there were too many many stars were there. But now, from few months I'm ...
2
votes
1answer
158 views

Should a station in orbit around the Sun travel in the same or the opposite direction to the planets?

If we put a station in orbit around the Sun, and wanted to send transports as regularly as possible without the travel costs being prohibiting; should we have it rotate around the Sun clockwise, or ...
2
votes
1answer
113 views

Was there ever a Jupiter transit or Saturn transit?

I've watched the Venus transit 2004 with a small telescope, a relatively rare event, considering most people can only observe two in their life time. If E.T. were sitting in a sunny place on a moon ...
2
votes
1answer
62 views

Spheres in space [duplicate]

I know that gravity will turn a mass into a sphere, which is why planets and stars are that shape. But then we have asteroids and small moons which are not spherical. Such as a couple of Pluto's ...
4
votes
0answers
32 views

What visual artifacts are expected from the JWST?

What visual artifacts should we expect from the images that will be released from the James Webb Space Telescope? Specifically, do we expect 3-pronged diffraction spikes (any preview how they would ...
4
votes
2answers
75 views

Understanding Earth Tilt, Sun's Position and Lattitude Calculation

I've been trying to figure out how to calculate the latitude of my location with just the shadow of a stick cast by the sun. I am doing this under the assumption that I am stranded in some place with ...
3
votes
0answers
78 views

How does light so travel so fast?. [duplicate]

I've read that photon's have zero mass, hence no force is needed to accelerate them. But then the second question. How can gravity affect something which has 0 mass?. Yes, gravity(black hole) can bend ...
6
votes
1answer
113 views

Could an impact have resurfaced Venus 300 million years ago?

Venus surface isn't older than about 300 million years. The only explanation I've come across is that some kind of global volcanism resurfaced the planet. But couldn't it have been an impact event? A ...
2
votes
0answers
27 views

Stratospheric Balloon with an Xray camera

Some colleagues and I were planning to launch a stratospheric balloon in December. A thought occurred to me: what if we were to put some sort of xray camera in the payload? We are expecting a maximum ...
3
votes
1answer
97 views

What is the format of the data from the JPL's HORIZONS system?

I'm looking for accurate positions and velocities of the planets in the solar system over several decades. I want to simulate their trajectories using Newtonian laws of motion, and compare the ...
1
vote
0answers
38 views

LIfe without an ocean floor on an ocean planet?

Theoretically, wouldn't life need some sort of an ocean floor with irregularities where organic "soups" could "condense"? What about "membranes"? Don't theories suggest that if life came to be near ...
2
votes
1answer
20 views

Biosignatures for anaerobic or other early microbiology?

What are some possible atmospheric bio-signatures for a planet with anaerobic life? or even microorganisms before oxygen builds up in the atmosphere? Would there be a way of telling if methane, etc. ...
4
votes
1answer
143 views

When will Sirius be closest to the solar system?

Sirius is currently approaching the solar system, at a rate of 5.5 km/s, consequently in the future it will be closer and therefore brighter. When will Sirius pass closest to the solar system? How far ...
2
votes
1answer
75 views

Can we know where (South, East, West…) the moon will be at a specific time?

Apparently, a few nights from now (more specifically on the night between the 27th and 28th of September this year, nights being Belgian nights), we will have a lunar eclipse. That's great, and I ...
7
votes
2answers
741 views

What causes the antipodal bulge?

The Wikipedia article on tides shows a diagram with a tidal bulge both towards the Moon and on the antipodal point (the Sun isn't included in the diagram). Surely that's wrong - what would cause the ...
9
votes
2answers
201 views

Does any iron fuse in stars before they go supernova?

I understand that iron and all heavier elements consume more energy to produce than they make, and that is what eventually leads to a supernova. I also understand that a lot of the heavier elements ...
3
votes
1answer
86 views

How to scale down solar system data to simulatable values

Okay, I am seriously ashamed for asking this especialy when I geniualy study on physics but there is something that bugs me with the simulation I am working on. I am re-creating the solar system in ...
2
votes
0answers
50 views

Universal point for sky observation

Is there a place on Earth, where polar axis lies on the horizont and heaven equator is in zenit? If it exists, can I, in theory, see all the constelations available worldwide this night?

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