8
votes
1answer
68 views

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 ...
8
votes
1answer
65 views

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 ...
12
votes
3answers
204 views

How can I safely observe a Solar Flare?

Solar Flares obviously release extreme amounts of energy and extend thousands of miles out into space. Because they are so big I would like to be able to observe some of these events through a ...
7
votes
1answer
75 views

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, ...
8
votes
1answer
107 views

Timescale of ignition of a protostar?

What is the timescale of start of nuclear fusion as T Tauri type star transforms into a Main Sequence star? Wikipedia article on T Tauri type stars mentions: Their central temperatures are too ...
6
votes
1answer
165 views

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 ...
1
vote
3answers
101 views

Why does Astronomy still use the Anno Domini system for Time Synchronization

Since Time is such a valuable variable in the calculation of Astronomic movement why does the Astronomy Community still rely on the the 6th Century Anno Domini system developed by Dionysius Exiguus to ...
5
votes
1answer
327 views

How much of an effect does the moon have on Earth's liquid mantle?

The gravitational pull of the moon is enough to create tidal forces of large bodies of liquid, i.e the sea. I was having a conversation the other day about how to terraform Mars, and someone ...
8
votes
2answers
238 views

How old is our Sun in Galactic years?

A year is measured as the amount of time it takes Earth to orbit the Sun once, a Galactic year is the time it takes our sun to make one full orbit of the center of the Galaxy. In Galactic years, how ...
7
votes
1answer
258 views

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 ...
4
votes
2answers
87 views

What is the furthest object in the observable universe?

My question is about furthest object in the observable universe except Сosmic microwave background.
9
votes
1answer
73 views

How Does Cosmology Constrain the Number of Neutrino Species?

I've asked this question already on the Physics SE, but I felt it would be worth posting here as well. I know that based upon theories of structure formation cosmologists can constrain the sum of the ...
14
votes
2answers
2k views

How does neutron star collapse into black hole?

We know the spectacular explosions of supernovae, that when heavy enough, form black holes. The explosive emission of both electromagnetic radiation and massive amounts of matter is clearly observable ...
5
votes
1answer
38 views

Is there any evidence that the Gas Giant planets in our solar system are experiencing orbital migration?

Planetary migration is defined by Lubow and Ida (2010) in their article Planet Migration as the process by which a planet’s orbital radius changes in time. The main agent for causing gas giant ...
6
votes
2answers
128 views

Why are some planets so close to their star?

"Kepler-10b orbits its parent star once every 0.84 days, which means it is more than 20 times closer to its star than Mercury is to our sun" space.com Are there any accepted theories that ...
9
votes
3answers
296 views

How to detect emission lines in optical spectra?

Is there any handy module to detect emission lines in a spectrum like one we get from the Sloan Digital Sky Survey (SDSS)? You can see there are many emission lines like Ha,OI in the spectrum below. ...
18
votes
2answers
389 views

How dense are Saturn's rings?

I assume that the A ring is the densest, but I might be wrong. Nevertheless, I failed to find any explicit information over the net about the minimum and maximum of densities for the different rings. ...
8
votes
1answer
67 views

Sources of Turbulence in the ISM

What sources of turbulence exist within the Interstellar medium (ISM)? Which ones are physically the most important for newly forming stellar systems?
5
votes
1answer
40 views

How can I observe the Orionid Meteor Shower?

I would like to see the orionids sometime this week (October 20-26, 2013). What is the best way for me to observe them by naked eye? Also, would I be benefitted by trying to look at them with a ...
7
votes
3answers
724 views

How long until we cannot see any stars from other galaxies?

Since all the galaxies are moving further away from each other at a faster and faster rate, eventually we won't be able to see stars from other galaxies. How long until we can't see stars from other ...
7
votes
1answer
58 views

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 ...
10
votes
1answer
118 views

Which came first: black holes or galaxies?

In other terms, did galaxies grow around black holes at their center?
10
votes
1answer
52 views

Loss of atmosphere on Mars

If the atmosphere on Mars was once much thicker, how was it likely lost? Was it due to interaction with the solar wind, the small size of the planet, both, or something else, and approximately how ...
8
votes
2answers
196 views

Why is the Earth's center still hot after millions of years? [closed]

Why didn't the center of the earth cool after millions or billions of years? What keeps it hot?
4
votes
5answers
647 views

Very bright star in the east at northern hemisphere. What is it?

From some time now (few weeks as far as I can remember), there is a very bright star in the eastern sky. I first thought it was Venus, but according to this link, Venus is in the western sky and ...
5
votes
1answer
137 views

How can we tell if the asteroid 2013 TV135 will hit Earth in 2032?

Some astronomers in Ukraine have estimated that there is a small likelihood (1 in 63,000) that the asteroid 2013 TV135 will strike Earth in 2032. (source) Don Yeoman of NASA JPL says: with more ...
6
votes
2answers
190 views

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), ...
5
votes
1answer
550 views

Why does Titan's atmosphere not start to burn?

If Titan has a methane atmosphere and seas of methane, then why doesn't some meteoroid / chemical reaction ignite and blow the whole thing?
1
vote
0answers
46 views

Is the moon rotation at complete standstill? [duplicate]

Moon always faces Earth with one side, its spin period equal its orbital period - this is what we learn at school. But I know Nature rarely operates in absolutes. I'd find it hard to believe Moon ...
8
votes
1answer
302 views

What reason is there to doubt the existence of the hypothesised planet Tyche in the far distant solar system?

Please note, I do not necessarily believe in its existence, just after a scientific (hence, non-Wikipedia) reasoning to doubt the planet's existence, other than the "we would have seen it" argument. ...
5
votes
1answer
250 views

Are Barlow lenses stackable for bright objects?

I'm back to the refractor that I own, and I want to maximize the zoom capacity. I realized today that I own more than one barlow lens, and I was wondering if I could stack them together for looking at ...
5
votes
1answer
47 views

Who or what will the Arecibo message reach?

The Arecibo Message was aimed at the globular star cluster M13, but as far as I read, M13 will move out of the original position and thus not be able to receive it. So, who or what will be able to ...
13
votes
3answers
148 views

When will we be able to detect Earth-sized exoplanets?

I have heard that the only planets able to be seen outside the Solar system are Jovian-sized planets with the occasional detection of planets three times the Earth's size. But, as far as I know, we ...
7
votes
1answer
165 views

In what timeframe is W26 expected to go supernova?

All the news-articles say that it is expected to "eventually" explode. Which doesn't really tell me much. When is "eventually"? Also, considering this is the largest star in the known universe and 16k ...
8
votes
1answer
60 views

How does interstellar matter density vary?

Answer to my question partially answers this one, about density of intergalactic matter and matter within galaxy: But it is mostly a hot, ionized void. How void? The density of the intergalactic ...
7
votes
1answer
47 views

Does the Reflection Method for Looking at the Sun Work For Refractors?

I own a newtonian reflector and occasionally use it (using the reflection method with paper) for looking at the sun. I happen to also own a refractor, but I'm not exactly sure if the reflection method ...
9
votes
1answer
209 views

How Does a Refractor Telescope Work?

As I understand it, the difference between a reflector and a refractor is that a reflector uses mirrors on the back to reflect the light to the secondary mirror then the secondary mirror reflects the ...
8
votes
1answer
113 views

Age of the universe

We know that the universe is approximately 13.7 billion years old. What methods did we use to discover this? How sure are we about its accuracy?
10
votes
3answers
443 views

How do we know dark matter/dark energy exists?

I've never quite understood the theory behind why dark matter and dark energy exist. I know it has something to do with gravitational pull being stronger than what we calculate it SHOULD be, could ...
-1
votes
1answer
61 views

What do shape of universe mean? [closed]

What shape does a three dimensional universe have ? and how did scientists determined that it is flat and not curved.
14
votes
4answers
454 views

What is in the center of the universe?

If the universe has formed & originated by a Big Bang Explosion, then there must be empty space left in the center of the explosion site, as all the matter is travelling at tremendous speeds away ...
26
votes
3answers
2k views

How powerful a telescope would allow me to view the astronauts aboard ISS do a space-walk?

This arose from a comment posted against a question elsewhere on the stackexchange How powerful a telescope/binoculars would allow me to view the astronauts aboard the ISS do a space-walk? Aperture? ...
6
votes
2answers
73 views

Are we moving ever closer to the center of our Galaxy due to a super massive black hole?

I've seen in documentaries that at the center of each galaxy is a super massive black hole which holds the galaxy together. Since black holes have such a strong pull, are we slowly being pulled in ...
4
votes
1answer
78 views

What study profiles could land me the job of Astronomer?

I realize there are very few to none universities that offer direct specialization of Astronomy. If I aspired to be make astronomy my career choice, I'd likely have to pick something like physics and ...
7
votes
1answer
120 views

What is the Lyman Alpha forest Used For?

The Lyman-alpha forest is an interesting feature found in the spectra of sufficiently distant objects. This series of absorption lines extends over a range of frequencies, and are a result of the ...
7
votes
1answer
38 views

Long term development of Comets

When an exocomet passes by our Sun in a trajectory that leads it to establish a Solar Orbit what eventually happens to it? In addition to its original inertia and vector being altered what are the ...
7
votes
1answer
102 views

Have we observed any rogue/wandering stars?

Do we know (have we observed and cataloged) any rogue star, being not part of galaxy, but drifting somewhere in inter-galactic space? I know that determining if a star is a part of galaxy or not is a ...
9
votes
1answer
270 views

How do we detect if a planet has a liquid core?

In case of Earth, we have many hints about the internal structure of our planet, from what I know, the most important of which is analyzing seismic waves. Do we have any instruments to detect if ...
2
votes
0answers
51 views

Which are the consequences of Uranus' high rotation axis angle? [closed]

The rotation axis of Uranus is 90 degrees away from vertical, there are some theories about its reason.. But which are the consequences of this? Which are the unique features of Uranus that happened ...
7
votes
1answer
93 views

What was the greatest spatial extent of the Asteroid Belt prior to the Late Heavy Bombardment?

Reading the article On the asteroid belt’s orbital and size distribution (Gladman et al. 2009), there is an interest point made: asteroids a few kilometers and smaller in size are recent ...

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