Questions tagged [the-sun]
Questions regarding the Sun, or Sol in Latin, the star at the center of the solar system Earth is in.
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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
97 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
130 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
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2answers
228 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 ...
3
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2answers
144 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?
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2answers
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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
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1answer
102 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?
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0answers
81 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?
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1answer
303 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 ...
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1answer
229 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?
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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 ...
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0answers
265 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-...
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2answers
156 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
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1answer
613 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 ...
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1answer
311 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 ...
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2answers
61 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?
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0answers
71 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
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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, ...
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3answers
537 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 ...
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1answer
212 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
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1answer
130 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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2answers
561 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 ...
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1answer
226 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
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1answer
106 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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2answers
323 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 ...
2
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0answers
85 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....
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1answer
147 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 ...
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2answers
316 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 ...
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4answers
2k 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.
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1answer
275 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 ...
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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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1answer
176 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
159 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 ...
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1answer
402 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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1answer
154 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 ...
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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.
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1answer
512 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 ...
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2answers
429 views
What is this white dot and strange line in SOHO image?
In the SOHO images for today, there was a white dot at the bottom right of the image. There is also a strange white line parallel to the top and bottom of the image that crosses most of the image. ...
5
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1answer
206 views
What are these echo-like artifacts in some SDO images?
I was looking at the Galleries in the NASA Scientific Visualization Studio and in the banner they show an image from SDO - the Solar Dynamics Observatory. I've posted it below along with a cropped, ...
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1answer
340 views
Local Time Calculation
How To Calculate Local Time Of A Sun Synchronous Orbit With A Given Altitude ( Say 600 km ) , Inclination ( 98 degrees ) ?
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Satellite Orbit-Sun Geometry of Sun synchronous Orbit
What is the difference in satellite orbit-sun geometry of Sun synchronous orbits of 6am local time , 9 am local time , 12 pm local time ?
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2answers
126 views
Using a probe to take gravitational measurements of the interior of the sun
Could one use a space probe to orbit the sun close enough to take measurements of angular / spherical gravitational field variations similar to what Juno plans to do for Jupiter?
Since the sun ...
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1answer
1k views
How strong is the Sun's gravity at the distance of Jupiter's orbit?
I had read that the Sun's gravity at the distance of the Earth's orbit was 0.0006 times that of Earth's gravity. So, I was wondering what it would be further out, at the distance of Jupiter's orbit.
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2answers
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Is this really an image of the sun, or an “artist's conception”?
I just saw this image in this article in Phys.org, which is generally a great source of physics news. Normally I would expect them to post real images, or if they use artist's conceptions, they would ...
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2answers
891 views
Nuking the Sun?
We know that according to Wikipedia on Nuclear fusion:
The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses ...
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2answers
172 views
A probe floating in Sun's surface
Is it possible to construct a probe that would float in the Sun's surface?
The temperature of Sun is 5,800 K and I heared there are alloys that can remain solid at 4500 K.
I wonder if it is ...
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5answers
724 views
Can you reach the Sun by only thrusting horizontally?
Suppose you have a hypothetical spacecraft launched from Earth.
When it escapes from Earth's gravity it will still be orbiting the sun at roughly the same velocity as the earth, approximately 30km/...
