<p>It is true that many of the things that we used to use eclipses for can now be done from space, continuously.</p>
<p>Eclipses are still important because they are usually much more easily accessible than space.  They happen right here on the surface, if you want to observe one, all you need is an aeroplane ticket. It's a lot less than a rocket!</p>
<p>That means that lots more and different people can be involved in observations, and with this you get repeatability and cross-checking. You can get amateurs confirming the relativistic displacement of stars due to the sun's gravity.  You can use a wide range of heavyweight equipment to repeat the observations by spacecraft, and by repeating, confirm them.  You can use eclipse timing to confirm and refine models of Earth's rotation and lunar perturbation.</p>
<p>So, it certainly is possible to observe the solar corona more easily from space, but that doesn't mean that observations can't be done from Earth, or that these have no value.</p>

CC BY-SA 4.0
2024-05-05T23:20:34.107Z
So, there is no science that can be performed exclusively from Earth's surface during totality? They are basically just adding more data points to further hone and verify space-based observations?
Curious Layman
CC BY-SA 4.0
2024-05-06T05:40:30.527Z
How about studies of "shadow bands"...  Can't study those in space.  Also my Earth rotatation timing examples
James K
CC BY-SA 4.0
2024-05-06T17:34:19.870Z
@CuriousLayman There's a number of biological/geological/atmospheric phenomenon (e.g. animal behavior or wind patterns) which can't be studied from space. There's probably no astronomical phenomenon which can be studied from earth during an eclipse that can't also be studied from LEO under the same eclipse. There are things which can be observed during an eclipse which are difficult or impossible to observe not during an eclipse, though there's ways (e.g. with a precisely sized metal plate) of effectively making artificial eclipses, though sun-moon interactions wouldn't come into play there.
R.M.
CC BY-SA 4.0
2024-05-07T11:41:52.657Z
"You can get amateurs confirming the relativistic displacement of stars due to the sun's gravity. " --- WHAT?? How can I do that?
BЈовић
CC BY-SA 4.0
2024-05-07T15:44:46.210Z
@BЈовић With today's optics, pretty much anyone can recreate Arthur Eddington's 1919 experiment that showed that Einstein was right and gravity can bend light. A lot of universities do it as a student project. Basically you're going to take a photo of the stars near the edge of the sun during the eclipse, then compare them to a photo of the same stars taken on any random night (ideally six months apart, I guess) and as you flip between them, you can see that the stars near the sun in the eclipse photo are out of place, which is due to their light being bent by the sun's gravity.
Darth Pseudonym
CC BY-SA 4.0
2024-05-07T16:47:06.753Z
@BЈовић  It's not as easy as Darth suggests. See the links from https://astronomy.stackexchange.com/questions/34830/was-the-suns-gravitational-lensing-observed-in-other-solar-eclipses-than-the-on  that is https://www.skyandtelescope.com/astronomy-news/amateur-astronomer-donald-bruns-receives-chambliss-award/ and https://skyandtelescope.org/sky-and-telescope-magazine/my-do-it-yourself-relativity-test/ and https://eclipse2017.nasa.gov/testing-general-relativity
James K
CC BY-SA 4.0
2024-05-12T11:19:31.050Z
@R.M. That was pretty much what I figured: totality is only good for biological and atmospheric phenomenon, as well as allowing more amateur astronomers a chance to conduct their own solar research. What sort of geologic phenomenon can be studied as well?
Curious Layman
CC BY-SA 4.0
2024-05-05T14:29:02.737Z
2024-05-05T14:29:02.737Z
James K
<p>I understand that total eclipses are a fantastic time to study the sun's corona, and the reason for this is because the much brighter photosphere is blocked by the moon. But, couldn't the <a href="https://science.nasa.gov/mission/parker-solar-probe/" rel="noreferrer">Parker solar probe</a>, which is so much closer, and without an atmosphere, capture better data? And, I'm not sure if this should be its own question, but if there is still something unique about totality for solar physics, is there any way to position a probe so that it constantly experiences totality? Such as in <a href="https://en.wikipedia.org/wiki/Lagrange_point" rel="noreferrer">Lagrange point</a> L2 of some planet? If not, is there some way to get a probe where it experiences a lot of totality? Or is constantly traveling around earth every year and a half to study the corona through our atmosphere for a few minutes at a time the best it gets?</p>

CC BY-SA 4.0
2024-05-05T07:53:17.607Z
Related: https://en.wikipedia.org/wiki/Coronagraph
PM 2Ring
CC BY-SA 4.0
2024-05-05T15:10:23.370Z
Do you have examples of major scientific efforts taken to study anything about the sun during an eclipse in modern times?  From what I understand, the existing satellites provide way more information now.  As you pointed out getting intrumentation in the path of an eclipse, hoping the weather cooperates, only to get a few minutes of data every couple years, isn't that helpful. I believe most of the science done is either citizen science (reproducing what we already know), or studying the effects the eclipse has on the Earth.
Greg Miller
CC BY-SA 4.0
2024-05-05T16:41:53.893Z
There's a lot of scientific research that's done during a total solar eclipse. But it does not study the Sun. Sounding rockets are launched to study Earth's ionosphere to see how it responds to the sudden lack of ionizing radiation. See for example [NASA to Launch Sounding Rockets into Moon’s Shadow During Solar Eclipse](https://science.nasa.gov/solar-system/skywatching/nasa-to-launch-sounding-rockets-into-moons-shadow-during-solar-eclipse/) and [Why the thermal imaging of Mercury's surface requires a telescope on a jet flying through an eclipse?](https://space.stackexchange.com/q/22411/12102)
uhoh
CC BY-SA 4.0
2024-05-05T16:49:15.413Z
and CNN's [Why NASA is launching rockets into the solar eclipse path](https://edition.cnn.com/2024/04/03/world/total-eclipse-science-research-scn/index.html) and Phys.org's [NASA to launch sounding rockets into moon's shadow during solar eclipse](https://phys.org/news/2024-03-nasa-rockets-moon-shadow-solar.html) which includes a cool video
uhoh
CC BY-SA 4.0
2024-05-05T23:25:32.533Z
@PM2Ring That was actually going to be another question I had. Is there science that can be performed during totality in a way that coronagraphs do not allow? Or is a coronagraph the exact same thing as totality?
Curious Layman
CC BY-SA 4.0
2024-05-05T23:38:27.883Z
@CuriousLayman This is not an observation of the sun, but the [Allais effect](https://en.wikipedia.org/wiki/Allais_effect) is an effect whose existence is contested, in which gravimeters on Earth allegedly behave strangely during a solar eclipse, first claimed in 1959. There have since been attempts during more recent eclipses to reproduce the effect.
C7X
<the-sun><the-moon><orbit><earth><orbital-mechanics>
What can be learned from viewing the sun on earth during a total eclipse that cannot be studied by spacecraft in orbit?
Curious Layman
# What can be learned from viewing the sun on earth during a total eclipse that cannot be studied by spacecraft in orbit?

(Asked by: username_0 on 2024-05-05)

I understand that total eclipses are a fantastic time to study the sun's corona, and the reason for this is because the much brighter photosphere is blocked by the moon. But, couldn't the [Parker solar probe](https://science.nasa.gov/mission/parker-solar-probe/), which is so much closer, and without an atmosphere, capture better data? And, I'm not sure if this should be its own question, but if there is still something unique about totality for solar physics, is there any way to position a probe so that it constantly experiences totality? Such as in [Lagrange point](https://en.wikipedia.org/wiki/Lagrange_point) L2 of some planet? If not, is there some way to get a probe where it experiences a lot of totality? Or is constantly traveling around earth every year and a half to study the corona through our atmosphere for a few minutes at a time the best it gets?

**Tags:** the-sun, the-moon, orbit, earth, orbital-mechanics

> **Comments:**
> **username_1**: Related: https://en.wikipedia.org/wiki/Coronagraph  
> **username_2**: Do you have examples of major scientific efforts taken to study anything about the sun during an eclipse in modern times?  From what I understand, the existing satellites provide way more information now.  As you pointed out getting intrumentation in the path of an eclipse, hoping the weather cooperates, only to get a few minutes of data every couple years, isn't that helpful. I believe most of the science done is either citizen science (reproducing what we already know), or studying the effects the eclipse has on the Earth.  
> **username_3**: There's a lot of scientific research that's done during a total solar eclipse. But it does not study the Sun. Sounding rockets are launched to study Earth's ionosphere to see how it responds to the sudden lack of ionizing radiation. See for example [NASA to Launch Sounding Rockets into Moon’s Shadow During Solar Eclipse](https://science.nasa.gov/solar-system/skywatching/nasa-to-launch-sounding-rockets-into-moons-shadow-during-solar-eclipse/) and [Why the thermal imaging of Mercury's surface requires a telescope on a jet flying through an eclipse?](https://space.stackexchange.com/q/22411/12102)  
> **username_3**: and CNN's [Why NASA is launching rockets into the solar eclipse path](https://edition.cnn.com/2024/04/03/world/total-eclipse-science-research-scn/index.html) and Phys.org's [NASA to launch sounding rockets into moon's shadow during solar eclipse](https://phys.org/news/2024-03-nasa-rockets-moon-shadow-solar.html) which includes a cool video  
> **username_0**: @username_1 That was actually going to be another question I had. Is there science that can be performed during totality in a way that coronagraphs do not allow? Or is a coronagraph the exact same thing as totality?  
> **username_4**: @username_0 This is not an observation of the sun, but the [Allais effect](https://en.wikipedia.org/wiki/Allais_effect) is an effect whose existence is contested, in which gravimeters on Earth allegedly behave strangely during a solar eclipse, first claimed in 1959. There have since been attempts during more recent eclipses to reproduce the effect.  

---

## 1 answers

### Answer by username_5 on 2024-05-05. Score: 14

It is true that many of the things that we used to use eclipses for can now be done from space, continuously.

Eclipses are still important because they are usually much more easily accessible than space. They happen right here on the surface, if you want to observe one, all you need is an aeroplane ticket. It's a lot less than a rocket!

That means that lots more and different people can be involved in observations, and with this you get repeatability and cross-checking. You can get amateurs confirming the relativistic displacement of stars due to the sun's gravity. You can use a wide range of heavyweight equipment to repeat the observations by spacecraft, and by repeating, confirm them. You can use eclipse timing to confirm and refine models of Earth's rotation and lunar perturbation.

So, it certainly is possible to observe the solar corona more easily from space, but that doesn't mean that observations can't be done from Earth, or that these have no value.

> **Comments:**
> **username_0**: So, there is no science that can be performed exclusively from Earth's surface during totality? They are basically just adding more data points to further hone and verify space-based observations?  
> **username_5**: How about studies of "shadow bands"...  Can't study those in space.  Also my Earth rotatation timing examples  
> **username_6**: @username_0 There's a number of biological/geological/atmospheric phenomenon (e.g. animal behavior or wind patterns) which can't be studied from space. There's probably no astronomical phenomenon which can be studied from earth during an eclipse that can't also be studied from LEO under the same eclipse. There are things which can be observed during an eclipse which are difficult or impossible to observe not during an eclipse, though there's ways (e.g. with a precisely sized metal plate) of effectively making artificial eclipses, though sun-moon interactions wouldn't come into play there.  
> **username_7**: "You can get amateurs confirming the relativistic displacement of stars due to the sun's gravity. " --- WHAT?? How can I do that?  
> **username_8**: @username_7 With today's optics, pretty much anyone can recreate Arthur Eddington's 1919 experiment that showed that Einstein was right and gravity can bend light. A lot of universities do it as a student project. Basically you're going to take a photo of the stars near the edge of the sun during the eclipse, then compare them to a photo of the same stars taken on any random night (ideally six months apart, I guess) and as you flip between them, you can see that the stars near the sun in the eclipse photo are out of place, which is due to their light being bent by the sun's gravity.  
> **username_5**: @username_7  It's not as easy as username_8 suggests. See the links from https://astronomy.stackexchange.com/questions/34830/was-the-suns-gravitational-lensing-observed-in-other-solar-eclipses-than-the-on  that is https://www.skyandtelescope.com/astronomy-news/amateur-astronomer-donald-bruns-receives-chambliss-award/ and https://skyandtelescope.org/sky-and-telescope-magazine/my-do-it-yourself-relativity-test/ and https://eclipse2017.nasa.gov/testing-general-relativity  
> **username_0**: @R.M. That was pretty much what I figured: totality is only good for biological and atmospheric phenomenon, as well as allowing more amateur astronomers a chance to conduct their own solar research. What sort of geologic phenomenon can be studied as well?  

---

