0
votes
1answer
31 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
135 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
40 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
21 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
57 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 ...
1
vote
1answer
62 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
69 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
14 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
65 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
vote
1answer
86 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
363 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
35 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
93 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 ...
4
votes
2answers
206 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 ...
-4
votes
3answers
210 views

Why there are other planets in our solar system? [closed]

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 ...
1
vote
1answer
104 views

Does one need to take into account finite gravity speed in N-body simulations?

Most small-scale N-body simulations (e.g., planetary systems, solar system, stellar clusters, ...) use classical Newtonian gravity. Most large-scale N-body simulations (e.g., galaxy clusters, ...) ...
1
vote
3answers
1k views

How much magnification is needed to see planets of solar system?

I have a 3inch Newtonian reflector telescope with 300 mm focal length. I can use highest magnification of 75x using a 4mm eyepiece. But in 75x I can't see details of Jupiter what was expected. Instead ...
5
votes
3answers
357 views

Why are all quasars so far away?

Why are all quasars so far away? If the universe is homogeneous, we could expect to have a homogeneous distribution of quasars, but all of then seem to be far away from Earth. Why is that?
2
votes
1answer
73 views

How long was the hyper inflation phase?

How long was the hyper inflation phase? Haw can we know that it lasted for a period of time and not more or les time?
1
vote
2answers
222 views

Why are gas giants colored the way they are?

As I understand it, Jupiter, Saturn, Uranus, and Neptune are all made primarily from varying proportions of hydrogen and helium. Despite this, Jupiter is very red, Saturn is yellow, and Uranus and ...
0
votes
3answers
211 views

How precisely is planetary tilt defined (the tilt direction, not just the angle)?

The earth's axis is titled 23.4 degrees with respect to the ecliptic. Since this tilt is responsible for the seasons, it's clear that the tilt is in the direction away from the sun on the shortest day ...
2
votes
2answers
476 views

What will happen when landing on Jupiter?

Jupiter is a gas giant, so landing on it will not be like as on Earth, our moon or Mars etc., as it does not have a solid surface like these. If we have a hypothetical spaceship or probe landing on ...
4
votes
1answer
131 views

Entropy of black hole

A line from one of the answers on a different question got me thinking: The simplest way to see this is probably that a black hole has a much higher entropy than a star or even another type of ...
3
votes
4answers
1k views

Does a black hole become a normal star again?

Stars which satisfy the Chandrasekhar limit can become a black hole. What happens to star after it becomes a black hole? Does it regain its status of star?
1
vote
1answer
55 views

Does the cosmic microwave background recede at the speed of light?

Does the cosmic microwave background recede at the speed of light? Is it possible it recedes even faster because of the stretching of space?
2
votes
2answers
95 views

Does the cosmic microwave background change over time?

Does the cosmic microwave background pattern change over time? I would assume it is getting "cooler" as in more redshifted as time passes, but I am more interested if the pattern on the background, ...
1
vote
2answers
115 views

Galaxy rotation curve and dark matter

I am reading "The Essential Cosmic Perspective" by Jeffrey O. Bennett, Megan O. Donahue, Nicholas Schneider, Mark Voit. In Chapter 14, it is stated that an evidence of the presence of dark matter in ...
7
votes
1answer
525 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 ...
0
votes
1answer
80 views

Find the height of the shooting star from the Earth's ground

One night, you and your friend were talking to each other. Your friend far about 20 km. from you. You told your friend that you see the shooting star pass through the sky at altitude of 75 degrees. ...
-1
votes
1answer
85 views

Calculate the time when Arcturus passed through the meridian

If the observer observes Arcturus passed through the meridian about 23:00:00 of 28 April. Find the time that Arcturus passed the meridian in 29 April. And what day does the Arcturus will pass the ...
-2
votes
1answer
178 views

Mass, Radius, Colour, Size, Type of a Star from the Hipparcos Catalog

Using data from the Hipparcos Catalog download file, is there a way to determine the Visual or Apparent Magnitude from the data within? Can I obtain the Mass, Radius, colour, temperature, type ...
0
votes
2answers
83 views

Could there be another planet between Mercury and the Sun?

Could there be another planet between Mercury and the Sun? Kepler found a lot of planets orbiting its star even 20 times closer than Mercury. If there were such planets in our system - would it be ...
2
votes
2answers
154 views

In geocentric models, did the earth rotate?

Under geocentric models, did the earth rotate around its axis? I assume that if the earth rotated around its axis, then the sun would not have to orbit around the earth at a very fast rate, whereas ...
5
votes
3answers
139 views

Is it possible to disprove geocentrism without telescopes?

The development of telescopes enabled the discovery of moons orbiting around Jupiter, and the existence of a full set of phases of Venus, as opposed to a limited set which would be predicted by ...
1
vote
2answers
47 views

What qualifies as a local star?

My professor used the term 'local star'. What range of distance is generally considered 'local' for a star? And what would be considered distant?
-4
votes
2answers
138 views

earth is spherical , does it mean the ground on earth is like a ball? [closed]

I know earth is spherical in shape. Does this means earths atmosphere is spherical in shape or the ground/(land+water combined) is in spherical shape. I have some doubts if the second is true. ...
0
votes
2answers
49 views

Why do we have so few neutrinos to study?

According to Wikipedia most neutrinos passing through the Earth emanate from the Sun. About 65 billion (6.5^10) solar neutrinos per second pass through every square centimeter perpendicular to the ...
0
votes
1answer
70 views

Why do not we use optical telescopes to study cosmic rays directly?

HESS, CTA, and VERITAS are used to study cosmic rays. What they receive are optical (maybe very blue) photons. So my question is: Why don't we use optical telescopes to study cosmic rays directly?
1
vote
2answers
134 views

How gently could a comet/asteroid/meteorite “hit” Earth?

Could an object from outer space with the right velocity and orbit come into contact with the surface of our planet in a "slowish" manner?
-1
votes
4answers
116 views

Light Cone Explanation

Not sure if this question belongs here, or on Physics. Would someone please describe the "anatomy" of a light cone and provide an intuitive example? I have read the Wikipedia article ...
4
votes
1answer
102 views

How Are Radioactive Decay Rates Influenced by Neutrinos - On Earth and Other Dense Planets

I read a science report recently that mentioned an accidental discovery where radioactive decay rates shifted slightly slower in advance ( about a day and a half) of solar storms or in sync with sun's ...
2
votes
1answer
115 views

Retrograde motion and Kuiper Belt Objects

As seen from Earth, planets such as Mars and Jupiter exhibit retrograde motion when they are near opposition (from Earth). I am wondering how this effect extends to very distant objects, such as ...
5
votes
1answer
101 views

Theoretical limits for natural satellites having natural satellites

Is there an inherent instability or limit that prevents natural satellites like the moons of Jupiter from having their own natural satellites? I looked at other questions such as do moons have moons ...
-2
votes
1answer
56 views

What “revolutionary” discoveries were made by Hubble Telescope [closed]

Forgive me for the naive question. Besides taking pictures of tons of objects in space, what kinds of revolutionary discoveries were made as a result of data from Hubble? Did Hubble shed light on any ...
2
votes
1answer
79 views

Calculating 2004 BL86 position using software

Is it possible to view asteroid 2004 BL86 using Stellarium or the iOS Star Walk app?
2
votes
2answers
119 views

How do stars or galaxies get their spin?

It is my understanding that when a star, a planetary disk, or a galaxy forms, the rotational momentum of the whole system is conserved. Due to the smaller size of the resulting object, it will spin ...
3
votes
0answers
81 views

Is there a cosmic, rather than technological, upper limit to what a telescope can resolve?

Space radio interferometers could have a baseline of millions of kilometers, but is there a point where a larger baseline doesn't improve the resolution anymore because the photons observed are ...
4
votes
3answers
186 views

Do objects look larger the further away they are, beyond z=1?

I stumbled upon this text which illustrates and says: We find that as the object is moved to higher redshifts its angular size first decreases (as naively expected) but soon begins to increase ...
1
vote
2answers
134 views

How to complete the Hipparcos Catalog?

I've downloaded hipparcos catalog from the Strasbourg Universe but whilst there is a lot of information, I can't find the names of the stars that the HipID relates to. There is the wikipedia page ...
-1
votes
2answers
96 views

The destruction of the Universe by a bubble

So I was watching a documentary on television about this and a number of theories that are proposed as to what the fate of the Universe will be: "Big Crunch" "Big Freeze" "Big Rip" I understand ...

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