All Questions

Filter by
Sorted by
Tagged with
0
votes
1answer
61 views

Can stars be observed from space by x-rays, near infrared and radio wavelengths? [closed]

I have a doubt. Can stars be observed from space by x-rays, near infrared and radio wavelengths?
4
votes
3answers
251 views

what is the current explanation for the formation of cosmic voids?

Why aren't galaxies distributed evenly in space, but instead form those sponge-like structures, with huge voids between filaments?
6
votes
3answers
3k views

Is Earth's 1g solid surface gravity unusually high for exoplanets?

The surface gravities of the Sun’s planets are all close to 1g, 0.38-2.53 (about a factor of e, by chance). The cloud-top gravity of the gas giants is not too interesting here, but I suppose that the ...
3
votes
0answers
117 views

Spectral analysis of AGN (velocity dispersion of galaxy absorption, doppler shifts)

I was wondering what parameters I need to know/measure to calculate the velocity dispersion of a galaxy, specifically an AGN. Also, I have spectra where there are blueshifted and redshifted ...
0
votes
1answer
305 views

What is the distance between 2 cities? [closed]

Both Quito and Kampala lie on the Equator. The longitude of Quito is 82°30'W and that of Kampala is 37°30'E. What is the distance from Quito to Kampala? A) along the shortest surface path B) along a ...
3
votes
2answers
127 views

Can we know the orbital planes of extraterrestrial planetary bodies?

Astronomers can tell if there are any exoplanets orbiting its parent star using but not limited to the following methods: Transit As an massive object usually a planet passing in front of a star ...
2
votes
0answers
197 views

How long until the stars are no longer visible by the human eye due to light pollution? [closed]

I was curious to how long it will be until the stars are not able to be seen due to light pollution. I started wondering this after reading Yummie's Flash comic Knite.
8
votes
1answer
250 views

How often are new astronomical objects (variable stars, supernovae, comets, etc) discovered by amateurs?

How often are new astronomical objects (variable stars, supernovae, comets, etc) discovered by amateurs? Where could one report new findings?
6
votes
2answers
465 views

Weight of a celestial body

How do astronomers find out the correct weight of a planet even though there isn't any direct means to weigh them? What technique do they use? Just curious!
4
votes
3answers
6k views

What would we find if we could travel 786 trillion light years in any direction

I've sometimes heard of galaxies that are millions or billions of light years away but if we could instantly travel 786 trillion light years in any direction, what are we likely to find? And what if ...
1
vote
1answer
525 views

Is the sun too small to self-ignite?

I recently heard in a discussion that the sun is not massive enough to self-ignite via core-pressure. It simply has not enough mass to "generate" the gravitational force needed for that. The reason ...
3
votes
1answer
316 views

Can the Universe be spatially closed and expand forever?

In the lambda-CDM model, the Universe is spatially flat, and will expand forever. Is possible that a spatially closed Universe expands forever?
7
votes
3answers
337 views

How should one rationally deal with the issue of space travelling alien civilizations?

What kind of reasoning is appropriate to understand the as of today unanswered question of whether there are (other) interstellar space travelling civilizations in the Milky Way? We have already sent ...
3
votes
1answer
546 views

Equations for coordinates of solar system objects

I would like to write a program that visualizes the solar system. To do this, I would need equations for calculating the coordinates of each solar system object at a given time. Where could I obtain ...
1
vote
1answer
49 views

Are there any works discussing planetary bodies being forms of life?

I'm searching for works or individuals that consider and discuss the idea of planetary bodies being considered stand alone living creatures, rather than objects either capable or incapable of ...
6
votes
1answer
204 views

Why is the Boomerang Nebula colder than the CMB?

An earlier answer on temperature mentioned that the temp of the CMB is 2.4K and the temp of the Boomerang nebula as 1K. How did the nebula cool faster than the CMB?
0
votes
1answer
75 views

Orbital Elements Mars near June 2014

do you know any website in which I could obtain orbital elements of planets at some date? For instance, I'm now needing the orbital elements of Mars around June, 2014. Thanks!
4
votes
0answers
86 views

Is there any astronomical phenomena that could emit strong radio waves with multiples of a discrete frequency?

In the New Scientist article Is this ET? Mystery of strange radio bursts from space, it is reported that several times since 2001, astronomers have detected fast radio bursts that seem to have a ...
10
votes
2answers
2k views

What would happen if a body were to fall into a neutron star?

We know neutron stars as a very massive object with extremely strong gravitational forces that composes mostly of neutrons. I couldn't help but wonder, what would happen if an object fell into a ...
15
votes
3answers
1k views

Calculate Distance To Stars

I was just watching a lecture from Carl Sagan. He talked about figuring out the distance to the stars; it got me interested in learning more about the subject. As far as I know, the Inverse square ...
8
votes
1answer
2k views

How much mass does an object in space need to keep a human on its surface?

Assume there were a roughly spherical object in space like a meteorite or a comet. If I weighed 80kg on Earth, how much mass would be required for an object in space so that I could stay on its ...
2
votes
1answer
181 views

Can we observe what objects exist at the L3 positiion of planets of our solar system?

From what I understand Earth's L3 is obscured by the Sun, so is that true for our viewpoint of the other planets? Or, are there times when other planets are on the other side of the Sun from Earth and ...
3
votes
1answer
197 views

Binary stars system ultimate fate

I read an article mentioning that when two stars orbiting each other they'll produce gravitational waves that can carry away energy into space. These phenomenon increases the speed of the two orbiting ...
4
votes
1answer
2k views

death of a red dwarf star / minimum mass needed for a white dwarf?

OK, first, I know there's a variety of sizes and types of red dwarf stars and the universe is too young for any of them to have reached the end of their main sequence phase yet, so it's all ...
1
vote
1answer
74 views

Is it possible to use the stars to determine the passage of time?

I'm writing a science fiction short story which involves a group of people being in suspended animation for a very long period of time, on the order of thousands of years. My question is, would an ...
1
vote
2answers
99 views

Is the Oort Cloud actually opaque, or is the “cloud” used euphemistically because minor planets inside of it are too dim to be seen?

I did read several of the Oort Cloud questions/answers which I found very helpful and instructive, but this question still persists for me: Is the Oort Cloud actually opaque, or is the "cloud" used ...
19
votes
3answers
2k views

Why can't we observe the Oort cloud with a telescope?

The Oort cloud is a hypothetical structure based on our observation of long-period comets. There are currently proposals to design probes to confirm the existence of the Oort cloud. Now, sending a ...
3
votes
2answers
1k views

Leaving the Milky Way

If we had a hypothetical spacecraft, would it be possible to exit our galaxy, wait for some time and enter back into another section? Will this method be more efficient that a more traditional flight ...
2
votes
2answers
978 views

What is the minimum size of a ball of gas to become a star?

I know there are two criteria to meet in order for nuclear fusion to occurs. High temperature (many times temperature at Sun's core) High pressure (protons are very close to each other) [Goal] ...
2
votes
2answers
226 views

Why are distant objects observed in the near infrared?

I was reading an article that explains why JWST is a successor to Hubble and not a replacement for Hubble. They explained that Hubble's science pushed astronomers to look at longer wavelength. And ...
32
votes
2answers
11k views

Can our Sun become a black hole

Does every star become a black hole? Is there any probability that our sun can become a black hole? If yes then is it on its way to become a black hole? what is the current state of sun as per the ...
0
votes
1answer
157 views

Around what apparent magnitude can the naked eye observe an object during full moon

For a very rough guideline using healthy/corrected eyes adjusted to the dark, around how bright should an object be to expect it to be visible?
2
votes
1answer
46 views

Do astronomers, in principle, have more information about older phenomena than younger?

The further away we see, the older states of the world we observe. And the volume of the part of space which is observable, increases by the square of the distance to it. So there should basically be ...
2
votes
3answers
474 views

BIG CRUNCH Theory

Someday before i read about a article which explained about a phenomenon called BIG CRUNCH, according to it the way Big Bang happened because of which the remains moved away from one another forming ...
3
votes
1answer
146 views

Why did Earth need material from comets to assemble the raw materials for life?

It's often speculated that matter from comets played a crucial role in the development of life on Earth. For example, Maps of Time says, Many of the ingredients of the early atmosphere (including ...
2
votes
0answers
87 views

are all the planet in the same plane? [duplicate]

are all the planet in solar system the same plane in the space or not ? if yes is there any especial reason ? and if no how do they orbits then ? as far as i know they are in the same plane , but is ...
1
vote
2answers
587 views

Where is Mars in the night sky

I live around Houston, Texas and I'm taking advantage of Earth hour to look at the stars. I've found two objects that I think might be Mars. Both of them are in roughly the same plane as Venus and ...
2
votes
2answers
2k views

Is a star powered by fission possible?

Stars can easily fuse atoms to give of heat and radiation. But at Wikipedia it said that only sub-iron atoms give of energy when fused and take energy when split, and post-iron atoms is the exact ...
1
vote
1answer
265 views

Is there a threshold on distance/size for a tidal locking?

I know that some systems tend to tidal locking (such as earth-moon), which occurs basically because the difference in the gravitational pull on one side is significantly different from the pull on the ...
1
vote
1answer
95 views

Does the sun have a feature like the red spot on Jupiter?

Does the sun have a feature or prominence like the red spot on Jupiter? Is there a feature that will remain as long as the red spot? Maybe beneath the surface?
0
votes
1answer
225 views

How to convert horizontal coordinates using NOVAS?

I'm using NOVAS 3.1. I know that I can convert equatorial coordinates to horizontal coordinates using the equ2hor function. Is it possible to make NOVAS do the ...
1
vote
2answers
2k views

Find constellation over Earth coordinates on a specific date-time

I would like some help in finding the exact constellations, or some sort of visualization of the stars over an specific location an time. The idea is to find out the closest star or group of stars on ...
4
votes
2answers
2k views

What is the direction of the movement of the solar system in relation to the galaxy's plane

I got from this answer that the axis of the solar system is tilted of about 63 degrees in relation to that of our galaxy, so I can assume that we move through space (at least locally) roughly in a ...
1
vote
3answers
363 views

Do we still use the term “astronomical unit” nowadays?

An astronomical unit is defined as the measurement of distance between Earth and our Sun, my question is since distances between celestial objects beyond our solar system are vast and unimaginable ...
13
votes
3answers
1k views

Aren't there more naked-eye-visible stars in the Milky Way plane?

Most stars which are visible to the naked eye are within 1,000 light years. The Sun is inside the Orion arm which has a diameter of about 3,500 light years. Thus, all stars (with very few exceptions) ...
6
votes
1answer
52 views

How does radio bandwidth restrict the choice and use of science payload on interplanetary probes?

I asked a question here about returning to Earth a physical memory capsule along with soil samples, as a complement to radio operations as today. This might return a much larger amount of data ...
5
votes
1answer
220 views

Gravitational pull needed to keep a gas in atmosphere

How can you determine the gravitational force needed to keep a particular gas in the atmosphere of a planet (for example, carbon dioxide (CO2))? I came across the following formula $\left(\frac{8RT}{...
1
vote
1answer
1k views

What is the typical resolving power of the largest optical telescopes?

I'd like to estimate the typical resolving power of the largest optical telescopes. I've calculated the theoretical resolving power of the VLA for 21 cm light, $$R=\frac{\lambda}{B}=\frac{2.1 \times ...
3
votes
2answers
270 views

What is the Northernmost Latitude of Saturn?

My wife and I were watching a TV show last night, which takes place in Salem, Massachusetts circa 1693. One character went to a particular place in the woods at a particular time to be exactly under ...
3
votes
1answer
72 views

.2015: When last did both New/Full moon in a fort-night cause an Eclipse?

Going through http://earthsky.org/…/dates-of-next-lunar-and-solar-eclipses I made the (what was for me - momentous) discovery that March 20, 2015 - New moon - is a Solar Eclipse, and that the ...

15 30 50 per page
1
156 157
158
159 160
180