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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12 votes
1 answer
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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 ...
Jeremy Friesner's user avatar
4 votes
2 answers
538 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 ...
uhoh's user avatar
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7 votes
2 answers
805 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. ...
Sub 6 Resources's user avatar
23 votes
7 answers
10k views

Do you need 0 km/s velocity to crash into the sun?

I was reading a popular thread about the delta-v required to escape the solar system compared to the delta-v required to crash into the sun. I get it: the earth itself already has a high speed (29.7km/...
ker2x's user avatar
  • 341
73 votes
5 answers
25k views

Why is it easier to escape the solar system than get to Mercury or the Sun?

It has been mentioned several times on this site that it is "easier" (less delta-v, and hence less fuel) to reach the escape velocity of the solar system, than to reach the planet Mercury or ...
DrSheldon's user avatar
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6 votes
1 answer
404 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 ...
SimpleMan's user avatar
  • 199
5 votes
2 answers
1k views

Orbital Mechanics and Launching into the Sun

Astronomy.com's Here's why we can't just rocket nuclear waste into the sun is an excellent explanation of the delta-V required to launch from Earth orbit into the Sun (30 km/s) vs. to escape from the ...
Dave's user avatar
  • 153
2 votes
2 answers
70 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 ...
uhoh's user avatar
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21 votes
2 answers
7k 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 ...
CJ Dennis's user avatar
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18 votes
6 answers
5k views

Could an Apollo crew have been killed by Solar radiation?

The Sun throws lots of high speed protons around. Especially during its sudden and short intensive "events". Much of that is blocked by Earth's magnetosphere and atmosphere. But astronauts work ...
LocalFluff's user avatar
8 votes
3 answers
1k 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 ...
Adám's user avatar
  • 1,597
6 votes
1 answer
290 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, ...
uhoh's user avatar
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3 votes
2 answers
530 views

Journey to the center of the Sun (best trajectory)

Let's assume there is unlimitedly rich eccentric person living nowadays, who has been just diagnosed with a kind of terminal cancer (estimates are 3 years left) and their last wish is to jump into a ...
Sergiy Lenzion's user avatar
3 votes
0 answers
140 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....
Gnubie's user avatar
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1 vote
1 answer
454 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 ...
Muze's user avatar
  • 1
28 votes
2 answers
5k views

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 ...
uhoh's user avatar
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18 votes
3 answers
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?
Alec Keyser White's user avatar
17 votes
2 answers
1k views

How can any probe be safe at one million degree Centigrade temperature?

Even after going straight inside the sun's corona, how can Solar Probe Plus be safe at the one million degree Centigrade temperature of the sun's corona ?
AmitG's user avatar
  • 289
15 votes
3 answers
739 views

Will or could the Parker Solar Probe do science at Venus?

Solar Probe Plus will flyby Venus 7 times(!) during 6 years in order to enter its "low" Solar orbit. Will it carry any instrument useful for studying Venus, for example seasonal changes? Would its ...
LocalFluff's user avatar
11 votes
2 answers
5k 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.
Dennis's user avatar
  • 111
9 votes
1 answer
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 ...
not_Prince's user avatar
  • 1,537
8 votes
1 answer
1k views

How are solar panels protected from the Sun?

In 2003, JAXA sent a probe, Hayabusa, to an asteroid named Itokawa. On the way to the asteroid, there was a large solar flare which damaged the probe's solar cells. I've been searching through the ...
duzzy's user avatar
  • 7,164
7 votes
5 answers
1k 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/...
aroth's user avatar
  • 677
6 votes
1 answer
2k 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.
Zauberin Stardreamer's user avatar
4 votes
3 answers
6k 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 ...
Eric Cartman's user avatar
4 votes
1 answer
693 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 ...
David's user avatar
  • 53
4 votes
1 answer
291 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 ...
Alexandru Lapusneanu's user avatar
4 votes
2 answers
2k 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 ...
Roger Pedrós Bòria's user avatar
4 votes
0 answers
1k 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-...
Tim Calhoun's user avatar
4 votes
3 answers
2k views

What are the problems with using the sun for Oberth maneuvers?

Presumably, it has something to do with the sun being rather hot. All the same, are there any potential cases with current technology where swinging close by the sun would be worth the shielding for ...
kim holder's user avatar
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2 votes
3 answers
8k 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 ...
Rex Gavsie's user avatar
2 votes
1 answer
730 views

How strong is Sun magnetic field on Moon surface? And on Mars?

I wan to calculate the voltage difference generated by sun EM Field on a wire placed on Moon or Mars surface, but I can't find consistent data about solar EM Field. I found different values: The ...
jumpjack's user avatar
  • 3,033
2 votes
0 answers
313 views

How to convert body coordinate from Sun reference frame to Earth reference frame?

I have the coordinates of a celestial body w.r.t. Sun , expressed as (x,y,z), at a given time. I need to move this coordinates into a reference frame centered on Earth center, but after reading dozens ...
jumpjack's user avatar
  • 3,033
2 votes
2 answers
333 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 ...
Muze's user avatar
  • 1
2 votes
2 answers
268 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? ...
Michael's user avatar
  • 29
2 votes
2 answers
147 views

Why did ESA's Solar Orbiter mission's target inclination drop from 34 to 25°?

Wikipedia says that: During the planned 7-year mission the orbital inclination will be raised to about 25° But the information below shows that originally the target final inclination was much ...
uhoh's user avatar
  • 149k
1 vote
2 answers
210 views

Does Perseverance have a gnomon on it?

Though How many sundials, Sun compasses and gnomons are there on solar system bodies? is as yet unanswered, Wikipedia's https://en.wikipedia.org/wiki/MarsDial currently tells us that only the ...
uhoh's user avatar
  • 149k
1 vote
0 answers
86 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 ...
uhoh's user avatar
  • 149k
0 votes
1 answer
342 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. ...
user avatar
-2 votes
1 answer
241 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 ...
Muze's user avatar
  • 1