The science dealing with objects and phenomena located beyond Earth. In particular, this applies to observations and data. At its core, astronomy is the physically informed cataloging and classifying of the contents of the universe in order to better understand what is out there.
2
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1answer
88 views
When would the proposed black hole at the centre of Milky Way gulp in our solar system?
I've heard and read that our solar system lies near to the peripheral region of the Galaxy. Then accordingly we would have a greater probability of sustaining to eventual gulping down by the ...
28
votes
8answers
5k views
Would it matter if the Earth rotated clockwise?
In the Futurama episode "That Darn Katz!" they save the world by rotating the Earth backwards saying it shouldn't matter (which direction Earth rotates). If Earth rotated clockwise and remained in ...
2
votes
1answer
287 views
Combined Gravitational Force Vectors in a Spherical Coordinate System
Asking a question here is quite intimidating for me -- while I love Physics, my high-school understanding only allows me to go so far... I've been trying to solve this problem for the last couple of ...
0
votes
1answer
95 views
Validity Of the Drake Equation [closed]
The Drake Equation is designed to estimate the number of Planets possibly having intelligent life forms existing in our Galaxy. But I don't see how it's justified. As far as we know, Earth is the only ...
1
vote
0answers
230 views
How to find orbital radius of star in a binary system using redshift and orbital period data? [duplicate]
Possible Duplicate:
About binary stars and calculating velocity, period and radius of their orbit
I am given the non-redshifted wavelength of the EM radiation from one of the stars, the ...
0
votes
2answers
81 views
On constancy of cometary orbits
how are the comets able to keep to a nearly fixed orbital period, though they lose a certain amount of mass during their perihelion?
2
votes
1answer
177 views
How early can scientists detect that a deadly asteroid will hit planet earth?
With the advancements in science and technology, how early can scientists of the world detect that a certain asteroid will hit planet earth and cause damage? Are there any impact avoidance strategies ...
1
vote
2answers
457 views
Could a solar flare cause the Earth's magnetic poles to reverse?
With all the hype of the impending "2012 Mayan doomsday" I was thinking it might be interesting to see what principles of physics prevent the theories of doomsday from occurring. One overarching ...
2
votes
1answer
87 views
Is the environment around an asteroid harsher than in interplanetary space?
In the wikipedia article about NEAR Shoemaker it is mentioned that the craft stopped operating under these conditions:
At 7 p.m. EST on February 28, 2001 the last data signals were received from ...
7
votes
2answers
202 views
Why don't we see solar and lunar eclipses often?
Since we see the new moon at least once in a month when the Moon gets in between of the Sun and the Moon at the night and as far as I know if this happens during the day, you'll get to see a solar ...
1
vote
1answer
691 views
Why don't we see solar and lunar eclipses often? [duplicate]
Since we see the new moon at least once in a month when the Moon gets in between of the Sun and the Moon at the night and as far as I know if this happens during the day, you'll get to see a solar ...
4
votes
2answers
340 views
What's the reason for the seasons?
In the diagram, it shows that the fundamental reason for different seasons is when the northern hemisphere is titled towards the sun there's summer in northern hemisphere and winter in southern ...
1
vote
3answers
100 views
Rocket needed to send 100 gram of mass to outer space? [closed]
What kind of rocket would be needed to send 100 gr of mass to outer space?
The mass can be moulded in any shape, but it would need not raise above 40 °C of temperature during the ...
2
votes
0answers
66 views
Calculating distance to an asteroid on a given day
I'd like to calculate the distance between the Earth and an asteroid at a given date. Is this possible using the data from JPL's small-body database? Is there a better way?
1
vote
1answer
298 views
RA/dec to Alt/Az program or method
I've been looking for a program to convert from RA/dec into Alt/Az; having used a couple of online versions I haven't seemed to find one yet that works reliably. I've tried to do it myself and half ...
2
votes
5answers
4k views
Why can I never see any stars in the night sky?
I have always lived near a large city. There is a stark contrast between the picture linked below for example, and what I see with the naked eye.
Sometimes I can see a few stars here and there, but ...
1
vote
1answer
120 views
How to calculate the amount of night time during a flight?
I have been asked to find a way to calculate the amount of time that a flight takes during night time.
So far, I have the departure latitude and longitude and the time of takeoff, the arrival ...
2
votes
3answers
701 views
What does Orion's Belt look like from the Equator?
I've been struggling with this question all morning, yet I get the feeling the answer is frightfully simple.
If Orion appears upside down in the Southern Hemisphere and the right way up in the ...
1
vote
1answer
495 views
How to determine day/night based on latitude, longitude and a date/time?
Is there a simple method of determining, given a UTC date/time, whether it is day or night at a given lat/long coordinate?
I am currently using a formula based on a Sunrise/Sunset Algorithm from the ...
5
votes
1answer
60 views
What prevents stars in globular clusters from merging over time to form a black hole?
Globular clusters are apparently very very old, and the density of these clusters appears to increase as one approaches the center of a cluster. Orbits are bound to be chaotic, since there is no ...
3
votes
2answers
180 views
Smithsonian Astrophysical Observatory (SAO) star catalog
Is a Smithsonian Astrophysical Observatory (SAO) star catalog, 4 volumes, dated 1977, worth keeping in a library or is it too outdated? Can it be used for epoch 200?
5
votes
4answers
538 views
Astronomy Experiments for Amateurs
Are there any resources online for astronomy experiments that I can perform myself?
I am looking if anyone knows any measurements to take while looking for various objects during the evening ...
1
vote
2answers
897 views
How to ‘correct’ reflected image on my telescope?
When viewed using my reflector telescope, the image, for example the moon, is flipped over and upside down (reflected). Therefore I need to do the ‘opposite’ movements when I want to align something. ...
6
votes
1answer
123 views
What sort of equipment would I need to take a photo like this?
I'm interested in doing some astrophotography and I'm looking into the equipment needed to get a photo like this: http://www.flickr.com/photos/cscunha1984/6619321531/in/faves-heyvian/
I'm not looking ...
3
votes
1answer
367 views
About binary stars and calculating velocity, period and radius of their orbit
I saw somewhere about being able to measure the velocity, period and radius of a binary star orbit by looking at red shift and blue shift.
I understand it but can someone give me an example of ...
6
votes
4answers
616 views
What are the best astronomy blogs and podcasts? [closed]
For someone who likes learning about astronomy what are the blogs and/or podcasts that I should be following?
3
votes
5answers
974 views
Having difficulties finding objects with Celestron Telescope
I have a Celestron Astromaster 114 EQ, which I saw was highly recommended as a great beginner scope. But I just can't seem to find anything in the sky with it. Yes, I've removed the lens cap, yes I've ...
1
vote
2answers
187 views
How can I visualize a gas giant?
From wikipedia
Gas giants are commonly said to lack solid surfaces, but it is closer
to the truth to say that they lack surfaces altogether since the gases
that make them up simply become ...
6
votes
1answer
438 views
How do we know the masses of single stars?
I have recently read that we can only know the masses of stars in binary systems, because we use Kepler's third law to indirectly measure the mass. However, it is not hard to find measurements for the ...
8
votes
1answer
14 views
Ring height stats?
I'm working on a basic simulation system which will include planets with rings, I want to create dust and asteroids within a 3D ring but I'm struggling to find any stats on the sort of height ranges a ...
5
votes
2answers
107 views
Io - Turned inside out
In a lot of the descriptions of the moon Io it frequently states that the moon, because of volcanic activity, has been literally "Turned inside out". What exactly is meant by "Turned inside out" and ...
12
votes
1answer
162 views
Impact location that created the moon
I was reading an article today about the 1000th orbit of the Lunar Reconnaissance Orbiter, and as many of you know NASA created an animation that simulates the history of the moon. It is speculated ...
3
votes
2answers
47 views
Figuring out which moons of Jupiter I saw through my telescope
Three days ago (Sunday 11st March) in London using my new telescope I was able to see Jupiter and three of its moons. It was very clear and easy to spot. How can I determine the names of the moons I ...
2
votes
1answer
162 views
May 20th Annular Eclipse - Duration from Vancouver?
On May 20th, there's an annular eclipse.
It's technically visible towards the end from Vancouver. In the middle, the duration is just under 6 minutes. What I want to know is what the duration is ...
10
votes
3answers
443 views
Can you damage your eyes viewing Venus?
Whilst I know it is extremely dangerous to view the sun using a telescope (or even just looking directly at it for prolong periods) can you do permanent damage to your eyes looking at Venus through a ...
3
votes
1answer
415 views
How to draw a star chart?
How does one draw a star chart like this?
I have:
a star database with coordinates (right ascension - RA, declination - DEC),
observer coordinates (latitude, longitude) and
time of observation.
I ...
10
votes
2answers
379 views
Is it possible to see satellites with the naked eye?
Every now and then I notice some very bright "stars" in the sky. They tend to be very few (one or two, usually), and are quite much brighter than any other star out there. Often they're perfectly ...
5
votes
1answer
19 views
Is there any site/place which gives access to astronomical signals acquired from space?
I am an engineer and I'd like to know if there are any places which provide access to any kind of astronomical signals acquired from space using radio telescopes.
2
votes
1answer
28 views
Existing photometry data of the open star cluster Cepheus OB3?
I am doing research with my teacher on photometry of the open star cluster Cepheus OB3, and we are trying to find research papers so we can target stars in the photos we took.
Are there any existing ...
6
votes
2answers
711 views
How can I determine if my telescope mirror is parabolic?
This week I purchased the “Skywatcher Explorer 130P Newtonian Reflector Telescope”, specifically as it has the parabolic mirror. I do not have the outer packaging for sundry reasons. Therefore, after ...
4
votes
1answer
391 views
Convert ECI coordinates to latitude/longitude?
I have been given output in (what I believe to be) ECI format (from OrbitTools):
...
6
votes
2answers
103 views
What's the best way to start out with astrophotography on a tight budget?
I'm new to astronomy and I don't have a great deal of cash to spend. I currently have a 3" reflector telescope which I've had great fun with. I also have a Pentax DSLR which I've been using to take ...
5
votes
3answers
326 views
Is there such a thing as “North” in outerspace?
On Earth, North is determined by the magnetic poles of our planet. Is there such a thing as "North" in outerspace? To put it another way, is there any other way for astronauts to navigate besides ...
6
votes
1answer
62 views
Why does Omega Centauri have a distinct chemical signature from the rest of the Milky Way?
In answering a question about the orbital path of Omega Centauri, I learned that it has a distinct chemical signature from the rest of the Milky Way. Basically, it is very rich in s-process elements, ...
6
votes
1answer
134 views
Frequency of nomad planets passing within 30 AU of the sun
A recent estimate by the Kavli Institute for
Particle Astrophysics and Cosmology (a joint
institute of Stanford and SLAC) is that there
are circa 100000 times as many 'nomad planets' as stars
I ...
3
votes
1answer
225 views
Sky-Watcher Skymax-127 (AZ) 127mm (5") f/1500 SynScan GO-TO Maksutov-Cassegrain Telescope
I have not purchased the above item yet but was wondering whether or not I should? Can I hook this scope up to a monitor or laptop so I can see what my scope is seeing? Is this scope is any good at ...
8
votes
1answer
75 views
Biggest crater in the Solar System
It seems that the biggest crater in the Solar System is Borealis Basin on Mars. The Wikipedia entry and this piece of news say it has been formed by an impact with a body of around 1600 - ...
6
votes
1answer
82 views
What is the orbital path of Omega Centauri?
I was under the impression the only objects relatively close to our Milky Way but not yet a part of it were the Sagittarius Dwarf and Large and Small Magellanic Clouds and then much further out, but ...
0
votes
1answer
110 views
How to find the orbit of a moving point object given 3 past passing positions?
How do I find the orbit of a moving point object given 3 past passing positions and the tangents at these passing positions, and given that the orbit is known to be an ellipse?
4
votes
2answers
129 views
Need help buying binoculars online for astronomy (10x50)
After reading much online I've decided to by a 10x50 porro prism Binoculars. The one I have in mind http://www.letsbuy.com/celestron-upclose-10x50-p-34652 has BK7 prisms. The one I would like to buy ...
