Solar Orbiter gets world-first views of the Sun's poles | Hacker News Reader

Solar Orbiter gets world-first views of the Sun's poles

esa.int

273 pointssohkamyung28 comments

This slightly tilted view of the poles is a teaser. I didn't know they'd managed to incorporate late in the mission gravity assists into the cheaper plan B to slightly tweak out of the ecliptic while dropping close to the sun. That's pretty cool. https://upload.wikimedia.org/wikipedia/commons/6/66/Animatio...

But we could've had so much more. The original proposal A for the ESA Solar Orbiter was a highly inclined orbit relative to the ecliptic plane to truly get full polar views of the sun. But this was too expensive. So they went with the cheaper proposal B which was mostly just a spectroscopic platform. Similar to SDO AIA, except in a solar orbit (almost completely within the ecliptic plane) instead of SDO AIA's Earth based sun synchronous orbit.

I suppose it takes a lot of deltaV to get a stable orbit over the sun poles?

You'd need to completely cancel out the rotation of the solar system, far beyond what we have the technology to do.

It's doable with gravity assists. Ulysses got up to 79° inclination using a Jupiter flyby.

https://en.wikipedia.org/wiki/Ulysses_(spacecraft)

It does, but most of the needed dV is harvested from the planets during gravity assists. The probe is accelerated/turned several hundred or thousand m/s and in exchange the planets it passes are shifted/slowed/turned by maybe 0.00000000000000000000001 m/s. In this case, the probe largely needs to slow down, to bleed of the speed it got from being at earth's orbit, so the planets are probably being accelerated.

They plan to get a more polar orbit each time they get close to Venus: https://www.esa.int/ESA_Multimedia/Images/2020/01/Solar_Orbi...

Not sure if 33° angle in 2029 is the final "polarity" or if they'll keep tilting after that.

Wouldn't the tilt affect the gravity assist of Venus?

The planning of sure, you've gotta make sure you're crossing the plane at the time, but gravity assist itself is otherwise the same though.

At the time, every time, and the position of Venus changes with every orbit. But I guess the folks at ESA are proficient in math.

you linked Parker probe, not Solar Orbiter

"But in the end, it doesn't even matter"

Huh, yeah, I am not entirely sure how that happened. I think copy buffer hijinks. How embarassing. https://upload.wikimedia.org/wikipedia/commons/2/23/Animatio...

I didn't even realize that we've never seen the sun's poles before as I just assumed we already scanned our star many times over.

A nice reminder of how patchy and limited our knowledge is despite the impression of the opposite.

Keep up the great work, humans!

Dambit. No hexagons. I think i might have lost an old bet.

LOL

Ha. I wonder what solar scientists were expecting here, how surprising would it have been if the sun did have polygonal storms like the gas giants?

From a simulation? NVidia had come a long way since you made the bet.

No. From the realwold cyclonic storms of Saturn and Jupiter that form unnatural-looking polygons at their poles.

https://en.wikipedia.org/wiki/Saturn%27s_hexagon

https://en.wikipedia.org/wiki/Jupiter%27s_South_Pole

That is fascinating. Next bet is if Saturn's hexagon will change into another n-agon in our lifetime. Obviously we'd need a probe to check.

‘World First’ is a poor choice of words. ‘First Ever’?

well, they are the first time they're seen on this world so I think it's fine.

There was a previous mission (Ulysses aka International Solar Polar mission) that sent back a lot of data but for whatever reason, they didn't have it send visual images. Big bright ball = no surprise, maybe.

It's our world's first -- maybe the others already got it.

Or better, "humanity's first".

Happened outside our world though!

I love this, seems so minor if not paying attention but it's absolutely mind blowing. Getting a view we never saw of the life giver, an object that used to be revered as a god, nearly every human alive I history has basked in it's light and heat, and the for the first time we are seeing it in full

This allegation is incorrect.

The Ulysses spacecraft had already did that in 1994-1995.

https://en.m.wikipedia.org/wiki/Ulysses_(spacecraft)

The article points out:

„The only exception to this is the ESA/NASA Ulysses mission (1990–2009), which flew over the Sun's poles but did not carry any imaging instruments. Solar Orbiter's observations will complement Ulysses’ by observing the poles for the first time with telescopes, in addition to a full suite of in-situ sensors, while flying much closer to the Sun. Additionally, Solar Orbiter will monitor changes at the poles throughout the solar cycle.“

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