Questions tagged [the-sun]
Questions regarding the Sun, or Sol in Latin, the star at the center of the solar system Earth is in.
84
questions
2
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1answer
126 views
Space and Newton laws
I've read some articles which explain that we can't totally rely on Newtonian gravity concepts for understanding the motion of objects in space.
My question is how the use of relativity helps us to ...
2
votes
3answers
220 views
What is the gravitational acceleration of the Sun?
What is the gravitational acceleration of the Sun?
I've seen numbers such as 274 m/s2, but that doesn't make sense to me seeing that relatively weak sources of spacecraft thrust such as Electric ...
6
votes
2answers
174 views
Is the Heliosphere as elliptical as this graphic suggests?
I noticed the following graphic being used in an article discussing the Voyager probes. It also appears on Wikipedia's Heliosphere page:
The same page states that:
On a broader scale, the motion ...
1
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0answers
44 views
Will ESA's Solar Orbiter crash into Venus? If so, why?
The BBC News article European SolO probe ready to take on audacious mission links to the ESA video shown below and contains this 5 minute audio interview with NASA deputy project scientist on the ...
1
vote
2answers
36 views
What is ESA's Solar Orbiter's target inclination?
The BBC News article European SolO probe ready to take on audacious mission links to the ESA video shown below and contains this 5 minute audio interview with NASA deputy project scientist on the ...
0
votes
1answer
39 views
How to deteremine the angle between Sun and 2 probes?
I have the orbital position and velocity and the orbital parameter of 2 spacecraft at LEO, how to define the angle between Sun - Probe 2 - Probe 1 in ECI frame (If you imagine at a point sun then ...
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votes
1answer
74 views
What happens if you put rings with the mass of several suns around a black hole? [closed]
Can someone also explain to me what happens from 7:24 to 9:20 (basically he creates a sun, locks it in place, the sun starts absorbing the black holes' rings and growing, it starts dropping pieces of ...
16
votes
2answers
6k views
Has any object launched from Earth gone into the Sun?
I've seen a lot of questions about the $\Delta V$ required to reach the Sun from the Earth (~22-30 km/s if I remember correctly), firing a bullet into the sun, etc.
But has this ever happened? Has ...
18
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3answers
5k views
Is it really ~648.69 km/s delta-v to “land” on the surface of the Sun?
According to the following diagram it would require ~648.69 km/s to do all of the intermediate transfers that would land you at or around the sun's surface at perigee. Is this a real number? How would ...
3
votes
1answer
85 views
Main issues space telescopes face when pointing in the same general direction as the Sun?
What are the main issues that space telescopes face when pointing at objects that are in the same general direction as the Sun? Why do they generally schedule their observing for objects in the ...
1
vote
1answer
96 views
PIR application as a sun sensor
Is there any history or merit to using a PIR (Pyroelectric ("Passive") InfraRed Sensor) as a sun sensor for determining the attitude or position of a Satellite?
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2answers
218 views
What Gravity does the Sun affect items with at the distance of 1 AU?
At the surface of the Earth, the force of gravity is defined as 1 G.
I am wondering what gravitational force the sun excerts at the distance of 1 AU (the distance Earth is at). Imagine it like this; ...
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1answer
143 views
How would molten or liquid metal be transported in open space? [closed]
How to transport a ball of liquid, molten metal nearest to the Sun possible? It must be close to the Sun for the metal to stay molten.
However, to stay safely cool enough, the spacecraft must always ...
2
votes
2answers
268 views
What is the shielding capability of liquid metal compaired to solid metal?
For simplicity, consider a spherical metal shape for shielding cargo/people behind. (The liquid ball is supposed to be between the Sun and the cargo. Not people inside it.)
A problem I see is that it ...
2
votes
2answers
172 views
Is a solar free-return trajectory possible?
I'm coining a new phrase: "Dyson circuit". Is it possible, with current solar orbital capabilities (see Parker Solar Probe), to drive artificial satellites in a free-return trajectory around the Sun?
...
1
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2answers
55 views
How do scientists determine how big a certain star is? [closed]
I was just wondering, many people say that there are stars that are waay bigger than our sun and in some videos they even try to say the exact diameter of the Sun, but I was wondering: How can ...
2
votes
1answer
134 views
How cold was it in the shade of the Parker solar probe?
What was the temperature in the shade of the Parker solar probe? Do to the proximity at the closest point the probe got to the Sun how much shade can be produced at that range?
3
votes
0answers
82 views
What is the effect of a solar flare on electronics on the surface of Mars?
Mars has practically no magnetosphere. Where does the impact of a solar flare on the electronics of Mars landers and rovers fall along the scale of nothing to EMP?
1
vote
1answer
328 views
Liquid shield for spacecraft? [closed]
Could an alloy of hot or cold liquid metal be made magnetic by adding electricity to the molten ball to give it magnetic properties to wirelessly attach it to a space craft to use as a shield shown in ...
2
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1answer
238 views
Parker Solar probe jumping through fire?
Is the principle of passing close the Sun with the Parker Solar probe the same as if you pass your hand over a candle flame fast enough you won't get burned?
9
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1answer
2k views
Could we possibly see the shadow offset from Parker Solar probe on Earth?
The closer an object to the source of light, the larger the shadow it casts.
Parker Solar probe would fly within 3.7 million miles (6 million kilometers) of the sun's surface. It sounds quite far ...
3
votes
0answers
423 views
Could the sun be used as a super-amplifier for SETI transmissions? [closed]
I just want to know if there is any scientific merit to this, the premise of Cixen Liu's novel, "The Three-Body Problem". English translation published in 2016.
See also Tor.com: Cixin Liu’s Award-...
3
votes
2answers
268 views
How would a Jupiter flyby have helped to get to the Sun? Why was it later ruled out?
The quote below surprised me. What were the orbital mechanical details of using a Jupiter flyby to get a probe from Earth so close to the Sun? Was a "U-turn" possible; single flyby of Jupiter into a ...
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0answers
79 views
Lighting an area of the Earth Surface from LEO
What does the math look like to calculate the size of an object in LEO that when angeled off the sun, would illuminate a part of the Earth's surface?
For example, if I wanted to 'lightup' a square ...
9
votes
1answer
650 views
Is it possible to reach the Sun without expending any fuel/reaction mass?
Imagine that I'm designing a space probe, that will initially be placed into an Earth-like orbit around the Sun.
My goal is to have the probe fly/fall into the Sun; it's allowed to take as much time ...
6
votes
1answer
328 views
Parker Solar probe's heat survival - Heat vs Temperature
This is not about about heat shields, materials, coolant, etc.
I am not quite not getting the science that explains the Heat Vs Temperature, which is how the Parker probe is going to survive the ...
1
vote
2answers
69 views
Can the Sun's magnetic field be used to propel a solar satellite?
Can diamagnetic materials or a diamagnetic devise be used to propel using the magnetic field of the Sun in a solar polar magnetic assisted slingshot?
7
votes
3answers
198 views
What is the Lux value of the Sun and Earth in Low Earth Orbit (altitude=400 km)?
I'm the Attitude Control System team lead on a cube satellite project, and we're trying to use cheap lux sensors to determine the body sun vector (vector adding the lux from each sensor). I want to ...
25
votes
3answers
4k views
What would happen if a satellite took a direct hit from a coronal mass ejection (CME)?
I was wondering what would happen if the average satellite were hit by an average CME. According to wikipedia the average velocity of a CME is 20 to 3,200 km/s. In addition to this it's super-heated, ...
7
votes
3answers
719 views
Is a sun-blocking orbit possible?
Is it possible for an orbital "sun shade satellite" to have a geosynchronous equatorial orbit such that it is in an approximately straight line between the Sun and a fixed point on the Earth's ...
0
votes
1answer
241 views
Could a spacecraft be propelled by the deflection of a very high number of charged particles?
I am wondering if a spacecraft could be propelled through interplanetary space via the deflection and/or displacement of a very high number of charged particles contained within the Sun's solar wind.
...
4
votes
1answer
154 views
What are the problems that need to be taken in consideration when trying to find planetary position by using jpl ephemerides?
I'm currently trying to determine the position of the sun and the moon from jpl ephemeris DE200 which is referred to the dynamical equator and equinox of 2000 and uses tdb time. I am using the j2000 ...
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votes
2answers
751 views
Solar Flux on Mars Surface
Considering that the Solar Flux on top of Mars' atmosphere is 590 W/m2 (following the 1/r^2 relation for sunlight), how much of this incident light actually arrives to Mars.
In other words, what is ...
2
votes
1answer
241 views
How quickly is the force of gravity exerted? Is a finite “speed of gravity” used in orbit calculations?
So I was reading a post of "What would happen if the sun disappeared".
An excerpt:
After eight minutes, the Earth would not only lose the sun's light and heat, but also its gravitational influence. ...
2
votes
1answer
120 views
Is communication from a spacecraft in SEL1 disturbed by the Sun?
A spacecraft at the Sun Earth Lagrange point one (1% of an AU, or one Solar diameter, from Earth towards the Sun) would have the Sun as its background. Is the Sun emitting strongly enough at ...
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3answers
4k views
Why does the ISS need thermal blankets if the Sun is hot?
If space is cold at 2.7 Kelvin and heat can't escape in a vacuum then why is the ISS wrapped in space blankets if the sun is hot?
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votes
2answers
360 views
How can a solar storm be predicted?
Satellites like DSCOVR are used to predict solar storms.
How does that work? If the satellite is orbiting L1 and "watches" the sun, how can the signal be back on earth before a storm arrives?
How ...
3
votes
0answers
118 views
What's the rationale behind the false colours in solar observation photographs? [closed]
Images from SOHO, SDO and other sun observatories are often coloured differently for different wavelengths or temperatures:
http://www.nasa.gov/mission_pages/sunearth/science/Sun-Wavelength-Chart....
8
votes
1answer
158 views
Could a probe fly through the Sun's transition zone between chromosphere and corona?
I wonder if a cryogenically cooled probe could fly very fast tangentially pass the Sun and through its transition zone where the temperature drops to below 6 000 K, from millions in the corona. What ...
5
votes
2answers
443 views
Which spacecraft will be the first for which the Sun would become the second brightest object in the sky?
Which spacecraft will be the first for which the Sun would become the second brightest object in the sky?
When that will happen and how far?
What would be the most efficient direction to fly in ...
11
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4answers
3k views
Is oxygen present in the sun? [closed]
If there is no oxygen in the sun, then how is it burning?
My question may be weird but I need a realistic answer for that.
4
votes
1answer
336 views
How much radiation shielding would be required for a habitat at Mercury–Sun L5?
Given an O'Neill "Island Three" style cylindrical habitat located at Mercury–Sun L5 orbit, how much radiation shielding would be required to protect the occupants, and how would it need to be ...
3
votes
3answers
1k views
What dangers are astronauts exposed to when facing the sun?
In this live stream, we have an astronaut facing the sun (we've seen his hands actually):
I thought people doing an EVA should avoid the sun at all cost, but here he's facing it.
From what kind of ...
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vote
1answer
197 views
Does Sunlight have a range? [closed]
If you switch on a lightbulb in a room its light has a visible range. So how about Sunlight? Does it light more on Mercury and less on Pluto? And what about planets that are not in the Solar System?
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1answer
166 views
Why is one of the foci of the ellipse of the trajectory of a space rocket in the center of the sun?
According to a book I am currently reading, space rockets and ballistic rockets fly along an elliptic path. However they differ in where the focus of the ellips describing their path lays. For space ...
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1answer
1k views
How to check, if there is currently an increased solar activity?
I've got an email, that because of the increased solar activity, more cosmic ray-s are hitting the earth. And for this reason, humans experience more stress and headache.
I know, it's not true. But I ...
5
votes
1answer
455 views
What are these dark lines in IRIS images of the sun?
Dark, narrow, straight lines move around within images from Interface Region Imaging Spectrograph (IRIS) in such a way that they appear intentional and systematic, and not just some imaging artifact ...
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vote
1answer
187 views
What thermal effect does the Sun have on spacecraft that are roughly the same distance from the sun as the earth is?
What thermal effect does the Sun have on spacecraft that are roughly the same distance from the Sun as the Earth?
Specifically, do spacecraft need to constantly rotate so that one side doesn't get ...
9
votes
2answers
3k views
Most distant photo of the sun?
What is the most distant photo taken of our sun? I am guessing it may be from Voyager 1, but can't find an actual photo anywhere.
6
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1answer
574 views
Need help simulating solar limb darkening
edit: At the Solar Dynamics Observatory (SDO) website, I just found the image sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_HMIIC.jpg. The color gradient of the limb darkening seems very similar to ...
