1
vote
1answer
30 views

How to view Jupiter with 4.5" Newtonian Reflector

I have a 4.5" Newtonian Reflector and I took a look at Jupiter the other night. I was able to get a reasonably sharp view of it and see a number of it's moons, but I was unable to see any surface ...
0
votes
1answer
65 views

Shouldn't all moon orbits be inherently unstable?

A hypothetical simulation starts with a planet called Earth in a perfectly circular orbit around a star called Sol. There is also a moon called Luna in a perfectly circular orbit around Earth. ...
1
vote
1answer
84 views

Could a close passing star be captured by the Sun's gravity?

Earlier I read an article here stating that a binary pair of stars passed within 0.8 light years from the sun. That made we wonder why the stars weren't captured by the Sun's gravity since the sun's ...
0
votes
3answers
103 views

Does the orbital variation in planetary gravity affect the Sun's corona

Dimitris (see below) argues that the syzygies of the Earth and Venus and those of Mercury, Earth and Jupiter distort the Sun's corona, which in some way affects climate on the scale of hundreds of ...
2
votes
2answers
64 views

Would a killer asteroid shattered into thousands of pieces produce the same devastation?

If we blow up a global killer (in the 3 - 20km range) days before impact into enough pieces that none of the them exceeds, let's say, a 30m diameter and the impact pattern is dispersed over most of ...
1
vote
3answers
93 views

Can planets inside the Earth's orbit around the Sun appear to undergo retrograde motion?

Retrograde motion is: The apparent motion of the planets when they appear to move backward (from east to west) from the direction that they move ordinarily with respect to the stars. Can planets ...
0
votes
3answers
86 views

What is our universe expanding into?

From inflation theory and other theories explaining the birth of the universe, the universe is expanding and recently it's been discovered that the expansion has been accelerating. My question is ...
2
votes
0answers
33 views

Radio Astronomy and Imaging

So, I've been starting to investigate radio astronomy, and am wondering about if certain things are possible from an amateur standpoint. I was looking at this powerpoint(that discusses building a tiny ...
0
votes
1answer
56 views

Is a black hole a 5 dimensional vortex?

We know that a black hole behaves like a whirlpool or a tornado or any of the other rotating phenomena we experience on Earth.But the thing is, all these phenomena, except the black hole, are ...
6
votes
1answer
503 views

Are there more stars than all the words ever spoken by humans?

A while ago I saw Neil deGrasse Tyson comparing the number of stars in the universe with the number of words spoken by all of humankind, ever since. I realize both of these numbers are not strictly ...
0
votes
0answers
23 views

What significance does coincidence or luck have in astronomy?

Astronomy is basically about looking around, and what happens to be there is very important for what we are able to discover. To what degree is astronomy shaped by coincidences in our neighborhood? ...
1
vote
2answers
52 views

Why does radio astronomy offer higher resolution images than optical?

According to this lecture,"Radio astronomy has several advantages over optical astronomy...We can make the highest resolution images, and see things happening on the smallest scales." Why is this? If ...
1
vote
1answer
34 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 ...
0
votes
1answer
32 views

How long does it typically take to make a telescope yourself for the first time? [closed]

How difficult is it to make a telescope oneself? How much time would it take for a first-timer? What are the typical pitfalls?
0
votes
1answer
66 views

How many galaxies are there in the Hercules–Corona Borealis Great Wall?

The Hercules–Corona Borealis Great Wall is "to date (February 16, 2015), it is the largest and the most massive structure known in the observable universe" (source). How many galaxies is the ...
-1
votes
1answer
49 views

What is the acceleration of the stars' speed in the Universe? Positive or negative? [closed]

I have read quite different opinions about that, so can someone tell me what is the sign of the acceleration of the stars in the Universe if we accept that the center of the Universe is the beginning ...
5
votes
2answers
343 views

Where do the heavier elements come from?

Partly inspired by this question, the end result of stellar fusion is Iron-56 (eventually, after some decay). Then it explodes. How/where then to the heavier elements come from. The answer here ...
0
votes
0answers
18 views

What are the up- and downsides of spherical and parabolic mirrors in telescopes?

What are the up- and downsides of spherical and parabolic mirrors in telescopes? I was able to find small bits of information from the web but not a good comparison. Assume the telescope is a ...
0
votes
2answers
31 views

Which eyepieces I can use it for best viewing experience using my exisiting telescope?

Telescope: Orion 09843 SpaceProbe 3,3 inch aperture(76mm), 700mm focal length, eyepieces - 25mm and 10mm focal lengths Hi, I am very happy and excited to see moon craters, jupiter and saturn. And ...
0
votes
1answer
28 views

Precessing of the Earth

It's been known that the Earth's axial tilt varies from 22.5 to 24.5. Does this result in a wobbling while the value of the tilt varies about these two limits? If so, how does it affect the mechanics ...
1
vote
1answer
88 views

Difficulties in finding Jupiter

I am new to astronomy. Jupiter is now visible to the naked eye but I have difficulties in locating it with my (new Newtonian reflector) telescope. The lowest magnification I have is 36X, which I guess ...
-2
votes
0answers
44 views

If life is adaptive as we believe, why isn't there gaseous dwelling life on Jupiter?

When considering the theory of evolution, if life can evolve from water dwelling creatures to land dwelling, why (theoretically) is there not life on every planet in our solar system?
2
votes
2answers
84 views

How would Jupiter's brightness relative to our sun seem to a remote observer (observing from a remote star)

Given that Jupiter is 5 AU from our sun and a remote observer viewing our solar system from some other part of our galaxy looks at it. We assume that Jupiter's radius is $11 \times 6700$ km. What ...
0
votes
0answers
37 views

Solar Eclipses for dummies: Step 1 - moon equatorial orbit around a planet without axial tilt

Note 1: I've studied downvoted questions and decided that I either asked too many questions or I sound like I'm setting a fantasy world. So I'm editing my question accordingly. Note 2: I'm a ...
4
votes
1answer
91 views

Estimating the angle covered by the star trails and deducing how long the exposure lasted

How would you estimate the angle covered by the star trails and deduce how long the exposure lasted in the following image? Here is the photo's caption: Star trails beyond the Gemini ...
2
votes
3answers
163 views

What would the night sky look like if Earth orbited an intergalactic star?

If the Earth and its host star were located exactly in-between the Milky Way and Andromeda would the night sky be completely void of light? Would stars be visible to the unaided eye? So there could ...
2
votes
2answers
87 views

Heat from other Stars

Does the Earth receive any heat at all from the millions of other Stars in our Galaxy ? Is it light that is bringing the heat and perhaps it cools down on the long journey in Space getting to the ...
11
votes
2answers
3k views

How did Kepler “guess” his third law from data?

It is amazing that Kepler determined his three laws by looking at data, without a calculator and using only pen and paper. It is conceivable how he proved his laws described the data after he had ...
2
votes
2answers
113 views

What astronomical observations would give conclusive proof of alien life?

There are several ways we are coming closer to answering the question "is there life elsewhere in the universe?". One is by first understanding very well the origin life on our own planet. Another is ...
1
vote
1answer
41 views

What kinds of technologies are required to directly image exoplanets

I have read that immensley powerful telescopes such as the European Extremley Large Telescope will be able to directly image the atmospheres of exoplanets, and even determine their rotation rates. I ...
-4
votes
1answer
36 views

What are the Gamma rays and Cosmic rays effects on humans and equipments? [closed]

First of all not to consider me a conspiracy theorist, but isn't landing on the moon a questionable issue? I am really not an expert in astronomy but let's assume that a moon landing has happened. 1- ...
1
vote
1answer
30 views

What uncertainty does an error bar signify in astronomy?

When an astronomer talks about her/his topic and shows an X/Y-plot with error bars. What should one assume that those error bars represent? 1 standard deviation? Or 2? Or some specific significance ...
2
votes
3answers
314 views

Circular orbits

First of all, I'm studying orbits for a hobby: world building. Unfortunately, my mathematical abilities approach a ridiculous low threshold, which means I am stuck with reading the simplest ...
0
votes
1answer
28 views

L4&L5 positions?

I know that, in L4&L5, the distances to the two main bodies should be equal. Still, how can I calculate that distance with accuracy? How can I know that that distance is inside the equipotential ...
1
vote
4answers
109 views

Relocation to Mars

One billion years into the future and the Sun has swollen in size and it is now not possible to live on Earth due to the heat. Mankind has relocated to Mars where the temperature is more favorable now ...
3
votes
1answer
31 views

Determination of orbital elements for Trans-Neptunian Objects, how?

How are orbits calculated for Trans-Neptunian Objects? I understand there are six standard parameters for defining an orbit (link) but I am not sure how telescope observations translate into these ...
3
votes
0answers
20 views

Estimates for how many Trans-Neptunian Objects there are [duplicate]

The Minor Planet Center shows that we know of about 1350 Trans-Neptunian Objects (TNO's). I think it is safe to assume that we have not found all the TNO's there are to find, even the ones that we ...
0
votes
0answers
51 views

Can an astronaut ever reach a Black Hole theoretically? [duplicate]

Ok, bear with me, while I try to explain the question I have. I read that time slows as we approach a black hole. So, suppose,theoretically, as astronaut is approaching a Black Hole. And he gets ...
-2
votes
0answers
27 views

What happens to light that travels further than the universe's expansion?

I asked a question about how far away the light was that would reveal the Big Bang (I'll link momentarily). A number of people did their best to explain to me that, from what I gathered among other ...
1
vote
1answer
50 views

How are parachutes usable in other places than Earth?

Mars landings, Moon landings. . . Wherever I see a documentary or still pictures in Wikipedia, there are parachutes in the landing of rovers. Whenever I see them, I ask myself, "How they can it ...
1
vote
2answers
50 views

Is it proper to refer to objects beyond Neptune as “Kuiper Belt Objects?”

It seems to me that nowadays the more proper term is "Trans-Neptunian Object". Is there any difference between Kuiper Belt Objects and Trans-Neptunian Objects? If not, is one term preferred over the ...
0
votes
0answers
11 views

Binocular with features like gleam night sight advantage?

Im looking for binoculars, I have seen specs like DAY & NIGHT ZOOM BINOCULARS, Full size day and night vision ,binoculars gleam night sight. Are these thing helpful when i look in ...
-2
votes
1answer
45 views

How are molecules detected in space?

Recently the sugar glycoaldehyde was detected in a star system 400 light years from Earth. How exactly are molecules detected in space? I am aware that spectroscopy is used to detect them, but I don't ...
-1
votes
0answers
31 views

Ice giants and Gas Giants

I had this speculation: I know that temperature and therefore internal pressure of a planet drops with its distance from the star, which explains why Uranus and Neptune are colder and smaller than ...
1
vote
1answer
72 views

Hubble HST scheduling algorithm

NASA developed SPIKE: Intelligent Scheduling of Hubble Space Telescope Observations (HST) and this. My question is simple, is there a programming library, preferably in python or C#, to implement the ...
1
vote
5answers
224 views

How far away is the light that would reveal the Big Bang?

I guess theoretically if we could go faster than light, which we clearly cannot, at some point we'd be able to see the big bang itself. Just curious - how far away is that light?
1
vote
1answer
33 views

Why would all places appear to be at the center of the universe's expansion?

I just watched an iMax planetarium video that claimed that no matter where you are in the universe, it will appear that you are at the center of the universe and all things are expanding away from ...
0
votes
1answer
67 views

If Kepler-444 planets existed for 11.2 billion years, why fear for life on Earth after six billion years?

According to recent news, Kepler-444, a 11.2 billion year old star, has a system of five planets. It has a mass of 3/4 of solar mass. So I believe both Kepler 444 and the Sun will share the fate of ...
3
votes
2answers
138 views

How do moons get captured?

[Apologies if this is a duplicate: I feel it ought to be, but my searches have failed]. A moon-sized object is running loose in the Solar System, perhaps after a planetary collision. As it approaches ...
-3
votes
3answers
92 views

Why there are other planets in our solar system?

Why there are planets in our solar system other than Earth? Only Earth supports life. What is the significance of other planets? Earth receives sunlight from Sun; in a similar way, do we receive any ...

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