23 votes
Accepted

Why does the Parker Solar Probe slow down as the distance from the Sun increases?

Why does the “parker solar probe” lose speed as the distance from the sun increases? Because energy and angular momentum are individually conserved quantities in the two body problem. Except for ...
David Hammen's user avatar
15 votes

Why does the Parker Solar Probe slow down as the distance from the Sun increases?

Quite simply, the sun's gravity is pulling on the space probe at all times. As the probe moves away from the sun, the force of gravity pulls it back in, slowing it down. As the probe moves toward the ...
Nuclear Hoagie's user avatar
10 votes
Accepted

Has Hubble photographed Venus in near IR? If so how does it compare to the new and exciting Parker Solar Probe image?

This web page -- "Here is why the Hubble Space Telescope only looked a few times at Venus (and why it looked at the Moon instead)" -- seems like a pretty good answer to your main question (...
Peter Erwin's user avatar
  • 16.7k
9 votes
Accepted

Did they ever figure out why Parker's WISPR cameras were able to see the surface of Venus? Mischaracterized filter, or unexpected atmospheric window?

There's actually a paper by Wood et al. (2022) that came out focused on this. It discusses the expected detection given the expected emission (using a model that combines the surface emission and the ...
Peter Erwin's user avatar
  • 16.7k
8 votes
Accepted

Why does the solar wind switch to flowing straight by the time it reaches Earth?

When plasma moves in a magnetic field then the charged particles follow helical paths around the field lines, due to the $q\vec{v}\times \vec{B}$ Lorentz force. If the radius of gyration is small, ...
ProfRob's user avatar
  • 152k
6 votes

Is the gravitational field of the sun uniform?

The Sun rotates, taking about 24.5 days to complete a revolution at the equator, a bit longer at the poles. This makes the Sun have a bit of an equatorial bulge, which in turn means that the Sun's ...
David Hammen's user avatar
5 votes

Why does the Parker Solar Probe slow down as the distance from the Sun increases?

The simplest explanation is that the satellite generally obeys Kepler's second law of orbital mechanics: A line joining a planet and the Sun sweeps out equal areas during equal intervals of time ...
johnDanger's user avatar
4 votes

How did Parker Solar Probe take what looks like 2D cross-sections of the solar wind in photographs; high contrast streaks in focus from volume effect?

The WISPR instrument is a visible light imager. You're right that it doesn't have a narrow depth of focus; it is basically focused at infinity. The video says we are seeing streams of plasma. The ...
giardia's user avatar
  • 2,088
3 votes
Accepted

The Sun's Alfvén critical surface; what was known about its existence and location before Parker Solar Probe "touched the Sun"?

I'm not sure this question is a meaningful one to ask because the "existence" of the Alfvén critical surface is implied by the very definition of it, which is a man-made construct. My answer ...
zephyr's user avatar
  • 15k
3 votes

What is happening with these solar particles detected near the Sun that is so newsworthy?

If I understand your question correctly, it is about EPI-Lo which a part of the Integrated Science Investigation of the Sun (ISʘIS) . The picture is also taken from there: EPI-Lo stands for Energetic ...
B--rian's user avatar
  • 5,616
2 votes

Does the Parker Solar Probe mission investigate the flow of currents near the sun?

Electric currents certainly flow in the corona. The idea that the corona is heated by electrical heating in turbulent current sheets goes back to Parker in the 1970s. Very large currents can be ...
James K's user avatar
  • 122k

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