Ken Hersey

[Hubble @NASAHubble]

How to get to views like these? On Hubble's Cosmic Adventure, of course!

Buckle up for an intergalactic journey. Answer questions, and let your choices lead you to an incredible destination in our cosmos. Try it here: https://t.co/NRcgiVSyUb

[Erika  @ExploreCosmos_]

Parker Solar Probe is one of the most extreme spacecraft ever built. It is currently flying through the Sun’s outer atmosphere, the corona, at about 430,000 miles per hour, or roughly 690,000 km/h, making it the fastest human-made object ever recorded. At that speed, it could cross the continental United States in around 20 seconds.

But the most remarkable part is not only how fast it moves. It is that it can survive while repeatedly passing just 3.8 million miles, about 6.2 million kilometres, above the Sun’s visible surface, closer than any spacecraft before it. NASA confirmed that Parker matched this record distance and speed again during its 27th close approach on March 11, 2026.

The spacecraft survives because of a very precise piece of engineering: its Thermal Protection System, usually called the heat shield. This shield is only 4.5 inches thick, about 11.5 centimetres, and is made from a lightweight carbon foam core placed between carbon-carbon composite panels. Its Sun-facing side is coated in a specially designed white material that reflects as much solar energy as possible.

The shield does not make the whole spacecraft immune to the Sun. Instead, it creates a protected shadow. The instruments and spacecraft body stay hidden behind it, while the shield takes the direct solar radiation.

This is why Parker Solar Probe can move through a region where the corona can reach temperatures of millions of degrees. That sounds impossible at first, but temperature and heat are not the same thing. Temperature measures the average energy of particles; heat is the amount of energy actually transferred to an object.

The corona is extremely hot, but it is also extremely tenuous, almost a vacuum compared with air on Earth. There are not enough particles there to transfer heat in the same way a dense gas or liquid would. The greater threat comes from intense sunlight and radiation, which is why the shield’s orientation is critical. If sensitive parts of the spacecraft moved out of the shield’s shadow during closest approach, they could be damaged very quickly.

Parker did not simply launch straight toward the Sun. That would actually require an enormous amount of energy because Earth is already moving around the Sun very fast. To fall inward efficiently, the spacecraft used repeated gravity assists from Venus, gradually reducing its orbital energy and lowering its closest approach to the Sun.

After its final Venus flyby in November 2024, Parker entered the orbit that allows these record-setting solar passes. Its extreme speed is mainly the result of falling deep into the Sun’s gravitational well: as it approaches the Sun, gravity accelerates it dramatically, and as it moves away, it slows down again.

Scientifically, Parker Solar Probe is important because it is measuring the Sun from inside the region where many key solar processes begin. It studies the solar wind, magnetic fields, energetic particles, plasma turbulence, coronal mass ejections, and the Alfvén surface, the boundary where solar material stops being magnetically tied to the Sun and escapes outward as solar wind.

These measurements matter because solar activity affects the whole Solar System, including Earth. Strong solar storms can disturb satellites, GPS, radio communications, aviation routes, astronaut safety, and even power grids.

The mission is also helping us investigate one of solar physics’ long-standing puzzles: why the Sun’s corona is far hotter than the visible surface below it. The photosphere is around 5,500 degrees Celsius, while the corona can reach millions of degrees. Parker’s close measurements allow us to test how magnetic reconnection, plasma waves, turbulence, and energetic particles may contribute to that heating and to the acceleration of the solar wind.

The deeper achievement of Parker Solar Probe is not just its speed, but its control.

It has to stay correctly oriented, manage its temperature, collect data, survive communication blackouts, and operate autonomously during the most dangerous parts of each orbit. It is not “touching” the Sun in a solid sense, because the Sun has no hard surface, but it is directly sampling the outer solar atmosphere in a way no previous spacecraft could.

In practical terms, Parker is showing that a spacecraft can survive at the edge of a star’s atmosphere with a shield thinner than many books, as long as the physics, materials, geometry, and autonomy are engineered with extraordinary precision.

[Space Telescope Science Institute @SpaceTelescope]

This #NASAWebb Red Spider Nebula image reveals the extent of the spider’s “legs,” the blue lobes, for the first time. Each bubble extends three light-years across, sculpted by gas from the nebula’s center. Credit: ESA, NASA, CSA.

[Ken Hersey @kenherseysj]

@jasminejaexxx 🍑🍑🍑🍑

[Ken Hersey @kenherseysj]

@AntGirl69 Ladies night ❤

[Ken Hersey @kenherseysj]

@Sarabellalondon Knee pads required... A man wishes to worship ❤

[Ken Hersey @kenherseysj]

It's been a while 🤣

[Ken Hersey @kenherseysj]

@Sarabellalondon You've convinced me to now believe in Aphrodite the goddess of beauty ❤

[Ken Hersey @kenherseysj]

@jasminejaexxx All of your delicious features are a hard choice 👍😉

[Ken Hersey @kenherseysj]

@Jelly_Beans42_ @WGer24 Invitation expected next time 👍😉

[Ken Hersey @kenherseysj]

@mercede72928186 Not to pry. Hope your ok

[Ken Hersey @kenherseysj]

@GoddessRaaynne Wedding vows

[Ken Hersey @kenherseysj]

@funsizedhaelle 🍑

[Ken Hersey @kenherseysj]

@mercede72928186 New look suits you ❤

[Ken Hersey @kenherseysj]

@Sarabellalondon @DefiantLs Spot on WTF

[Ken Hersey @kenherseysj]

@eliza__smoke But true 👍

[Jamie Kay @TheRealJamieKay]

Tesco going the extra mile.