APOD: Mercury Visualized from MESSENGER (2017 Dec 11)

[APOD Robot]

Mercury Visualized from MESSENGER

Explanation: What would it be like to fly over the planet Mercury? Images and data taken from NASA's robotic MESSENGER spacecraft that orbited Mercury from 2011 to 2015 have been digitally combined to envision a virtual flight that highlights much of the hot planet's surface. In general, the Solar System's innermost world appears similar to Earth's Moon as it is covered by a heavily cratered gray terrain. MESSENGER discovered much about Mercury including that shadows near its poles likely host water ice. The featured video opens as Mercury is viewed from the Sun-facing side and concludes with the virtual spacecraft retreating into Mercury's night. Mercury actually rotates so slowly that it only completes three rotations for every two trips around the Sun. In 2018, Europe and Japan plan to launch BepiColombo to better map Mercury's surface and probe its magnetic field.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

[LMMT]

Amazing!, congratulations!

[Confused]

Is that really what Mercury sounds like? Was this taken while inside its atmosphere because I don't know how else sound could gotten into this. After viewing this I will always remember Mercury screeching as much as some performers. You should warn people about the screeching.

[Alexander331]

Impressive. Is it the real sun in the end or did they add digitally ?

[rstevenson]

Is that really what Mercury sounds like? Was this taken while inside its atmosphere because I don't know how else sound could gotten into this. After viewing this I will always remember Mercury screeching as much as some performers. You should warn people about the screeching.

I am also confused -- by your excessive reaction. I hear quiet contemplative music which I find quite enjoyable. Maybe you should think about adjusting your computer's sound output.

Rob

[barobins@telusplanet.net]

Will Mercury ever plunge into the Sun? What would happen to Earth should that happen? Would it be thrown out of it's orbit??

[De58te]

Yes, I also am curious whether that is the actual sound vibrations Mercury makes rotating, that an astronaut in orbit would hear, or whether that is lower subliminal sounds that were processed for humans to hear?

[JohnD]

It gave Mercury a strange appearance, as if it was transparent over a deeper solid surface, like dust and leaves floating on a puddle.
Anyone else have that sensation?
John

[Chris Peterson]

Will Mercury ever plunge into the Sun? What would happen to Earth should that happen? Would it be thrown out of it's orbit??

No. Eventually the Sun will expand outward so far that Mercury will be inside it, at which point drag will likely result in it spiraling down into the Sun's interior and eventually being vaporized. This will have no effect on any of the other planets (although the Earth will share a similar fate somewhat later).

[Chris Peterson]

It gave Mercury a strange appearance, as if it was transparent over a deeper solid surface, like dust and leaves floating on a puddle.
Anyone else have that sensation?

I do see the illusion you are referring to.

[JohnD]

Glad it's not just me.
Artefact of the animation??
JOhn

[Chris Peterson]

Glad it's not just me.
Artefact of the animation??

I would think so. The surface is being simulated, apparently using a combination of imagery and altimetry (note the simulated shadows which change with solar angle). It's also possible that the altimetry is being synthesized from the imagery, which could easily lead to artifacts.

[Confused]

I am also confused -- by your excessive reaction. I hear quiet contemplative music which I find quite enjoyable. Maybe you should think about adjusting your computer's sound output.

So is it Mercury or is it music? There are thousands of places people can go to listen to music. If it is music then I suppose it is added since so many people live in a world with music playing that they can't do anything without it.

[bystander]

So is it Mercury or is it music?

Music: Open Sea Morning by Puddle of Infinity

[MarkBour]

So is it Mercury or is it music?

Music: Open Sea Morning by Puddle of Infinity

I can recall being surprised that instrumental music was included on a JPL or a NASA video once or twice, but I think it is pretty common to do so now, particularly when one is just "looking at landscape", so I no longer think about it. I have some trouble believing that anyone would think it was actual sound from nature, but I guess it is a slight risk for misinterpretation.

It gave Mercury a strange appearance, as if it was transparent over a deeper solid surface, like dust and leaves floating on a puddle.
Anyone else have that sensation?
John

I noticed it too, and guessed it was from trying to induce proper movement of frames that did not match up at the edges or something.
But I like how you put it. Kind of like it was a semi-transparent planetary crust.

By the way, when I was a kid, they told me that Mercury was tidally locked to the Sun, 1 rotation per revolution (synchronous rotation). Today I learned that instead, Mercury is much more interesting! It has been locked into a "Rotation–orbit resonance" of 3:2 (3 rotations per 2 revolutions). And this results in:

• The planet does have day and night everywhere on the surface other than the poles;
• The day (sunrise to sunrise, not sidereal) is two times as long as its year;
• The apparent movement of the Sun across the sky is very slow at perihelion, probably almost stops, but not quite;
• The earlier mistaken information that Mercury was tidally locked is somewhat forgivable. It is *hard* to observe the surface of Mercury from Earth. And there are only certain times and positions where you can get a relatively good look, and those times were in resonance of the motions of Earth and Mercury in such a way that observers were fooled into missing the complexity of Mercury's motion. But at least some people knew better even when I was a child. But pre-internet, it was nothing to be learning from materials that were a decade or more old.

[BDanielMayfield]

By the way, when I was a kid, they told me that Mercury was tidally locked to the Sun, 1 rotation per revolution (synchronous rotation). Today I learned that instead, Mercury is much more interesting! It has been locked into a "Rotation–orbit resonance" of 3:2 (3 rotations per 2 revolutions). And this results in:

• The planet does have day and night everywhere on the surface other than the poles;
• The day (sunrise to sunrise, not sidereal) is two times as long as its year;
• The apparent movement of the Sun across the sky is very slow at perihelion, probably almost stops, but not quite;
• The earlier mistaken information that Mercury was tidally locked is somewhat forgivable. It is *hard* to observe the surface of Mercury from Earth. And there are only certain times and positions where you can get a relatively good look, and those times were in resonance of the motions of Earth and Mercury in such a way that observers were fooled into missing the complexity of Mercury's motion. But at least some people knew better even when I was a child. But pre-internet, it was nothing to be learning from materials that were a decade or more old.

That is all interesting Mark, but in the wider universe Mercury has lost much of its "hotness" in recent years with the discovery of hundreds of exoplanets and even whole systems of planets with way tighter orbits.

[BDanielMayfield]

Will Mercury ever plunge into the Sun? What would happen to Earth should that happen? Would it be thrown out of it's orbit??

No. Eventually the Sun will expand outward so far that Mercury will be inside it, at which point drag will likely result in it spiraling down into the Sun's interior and eventually being vaporized. This will have no effect on any of the other planets (although the Earth will share a similar fate somewhat later).

Yeah, Mercury is toast for sure. But with its elliptical orbit it should put on an interesting show for a relatively short while as it skims the Sun's surface at periastron. Perhaps it will briefly "plunge" beneath the Sun's photosphere several times only to re-emerge on the outward part of its orbit. But it's doomed, as its orbit decays and the Sun swells.

Bruce

[Boomer12k]

Terrific...nice views...

:---[===] *

[MarkBour]

Will Mercury ever plunge into the Sun? What would happen to Earth should that happen? Would it be thrown out of it's orbit??

No. Eventually the Sun will expand outward so far that Mercury will be inside it, at which point drag will likely result in it spiraling down into the Sun's interior and eventually being vaporized. This will have no effect on any of the other planets (although the Earth will share a similar fate somewhat later).

Yeah, Mercury is toast for sure. But with its elliptical orbit it should put on an interesting show for a relatively short while as it skims the Sun's surface at periastron. Perhaps it will briefly "plunge" beneath the Sun's photosphere several times only to re-emerge on the outward part of its orbit. But it's doomed, as its orbit decays and the Sun swells.
Bruce

Interesting speculations. As the Sun swells, I wonder how the solar wind density will change, and the extent of the corona. With a temperature of that environment being around 1 million degrees, I suppose Mercury would become an "ocean planet" at the last. (Ha! A good question for the IAU then would be at which point it would cease to meet the definition of a planet )

[BDanielMayfield]

No. Eventually the Sun will expand outward so far that Mercury will be inside it, at which point drag will likely result in it spiraling down into the Sun's interior and eventually being vaporized. This will have no effect on any of the other planets (although the Earth will share a similar fate somewhat later).

Yeah, Mercury is toast for sure. But with its elliptical orbit it should put on an interesting show for a relatively short while as it skims the Sun's surface at periastron. Perhaps it will briefly "plunge" beneath the Sun's photosphere several times only to re-emerge on the outward part of its orbit. But it's doomed, as its orbit decays and the Sun swells.
Bruce

Interesting speculations. As the Sun swells, I wonder how the solar wind density will change, and the extent of the corona. With a temperature of that environment being around 1 million degrees, I suppose Mercury would become an "ocean planet" at the last. (Ha! A good question for the IAU then would be at which point it would cease to meet the definition of a planet )

Mercury will come to have a liquid metallic surface, and thus its name will be even more fitting near its end.

[Snooky]

It appears that this was put together from a whole year's worth of observations. The planet rotates about one and a quarter times or a little more during the course of the video. Very nice!

[Chris Peterson]

It appears that this was put together from a whole year's worth of observations. The planet rotates about one and a quarter times or a little more during the course of the video. Very nice!

I think it isn't put together by stitching images at all. From the description, it seems that the final result is a synthesis, with things like shadows being cast digitally. If so, we could be looking at images collected over any particular period of time and in any particular order, with the final result equivalent to a single video made over about a year.

[neufer]

Will Mercury ever plunge into the Sun? What would happen to Earth should that happen? Would it be thrown out of it's orbit??

No. Eventually the Sun will expand outward so far that Mercury will be inside it, at which point drag will likely result in it spiraling down into the Sun's interior and eventually being vaporized. This will have no effect on any of the other planets (although the Earth will share a similar fate somewhat later).

Yeah, Mercury is toast for sure. But with its elliptical orbit it should put on an interesting show for a relatively short while as it skims the Sun's surface at periastron. Perhaps it will briefly "plunge" beneath the Sun's photosphere several times only to re-emerge on the outward part of its orbit. But it's doomed, as its orbit decays and the Sun swells.

By my calculations when the Sun's corona reaches out to Mercury
it will start to intercept about 50 x 10¹⁶ kg of material per 88 day orbit.

Since the mass of Mercury is only 33,000,000 x 10¹⁶ kg
it should begin to rapidly dissipate kinetic energy over a period of ~660,000 orbits or ~160,000 years.

Note, however, that Mercury will transition into a circular orbit long before it reaches the chromosphere or photosphere.

[Chris Peterson]

Yeah, Mercury is toast for sure. But with its elliptical orbit it should put on an interesting show for a relatively short while as it skims the Sun's surface at periastron. Perhaps it will briefly "plunge" beneath the Sun's photosphere several times only to re-emerge on the outward part of its orbit. But it's doomed, as its orbit decays and the Sun swells.
Bruce

Interesting speculations. As the Sun swells, I wonder how the solar wind density will change, and the extent of the corona. With a temperature of that environment being around 1 million degrees, I suppose Mercury would become an "ocean planet" at the last. (Ha! A good question for the IAU then would be at which point it would cease to meet the definition of a planet :-))

Mercury will come to have a liquid metallic surface, and thus its name will be even more fitting near its end.

It may not. The outer part of a red giant is remarkably tenuous and cool. That combination means that planets may orbit inside the expanded Sun for thousands of years without melting. Of course, it may be a lot rougher ride for Mercury than for Earth or Mars.

[neufer]

[b][color=#0000FF]Sun-like stars have a degenerate core on the red giant branch and ascend to the tip before starting core helium fusion with a flash.[/color][/b]

---

As the Sun swells, I wonder how the solar wind density will change, and the extent of the corona. With a temperature of that environment being around 1 million degrees, I suppose Mercury would become an "ocean planet" at the last.

Mercury will come to have a liquid metallic surface, and thus its name will be even more fitting near its end.

It may not. The outer part of a red giant is remarkably tenuous and cool. That combination means that planets may orbit inside the expanded Sun for thousands of years without melting. Of course, it may be a lot rougher ride for Mercury than for Earth or Mars.

The sub-solar point on Mercury is already 700 K
... about half the lava temperature of ~1400 K

The Sun only has to become about 16 times as luminous to turn the sub-solar point on Mercury to ~1400 K lava.