Cherenkov Radiation: When Electrons Go Faster Than The Speed Of Light!

Why Won’t Our Parker Solar Probe Melt?

This summer, our Parker Solar Probe will launch to travel closer to the Sun than any mission before it, right into the Sun’s outer atmosphere, the corona.

The environment in the corona is unimaginably hot: The spacecraft will travel through material with temperatures greater than 3 million degrees Fahrenheit. 

So…why won’t it melt? 

The Difference Between Heat and Temperature

Parker Solar Probe was designed from the ground up to keep its instruments safe and cool, but the nature of the corona itself also helps. The key lies in the difference between heat and temperature.

Temperature measures how fast particles are moving, while heat is the total amount of energy that they transfer. The corona is an incredibly thin and tenuous part of the Sun, and there are very few particles there to transfer energy – so while the particles are moving fast (high temperature), they don’t actually transfer much energy to the spacecraft (low heat).

It’s like the difference between putting your hand in a hot oven versus putting it in a pot of boiling water (don’t try this at home!). In the air of the oven, your hand doesn’t get nearly as hot as it would in the much denser water of the boiling pot. 

So even though Parker Solar Probe travels through a region with temperatures of several million degrees, the surface of its heat shield will reach only about 2,500 F.

The Heat Shield

Of course, thousands of degrees Fahrenheit is still way too hot for scientific instruments. (For comparison, lava from volcano eruptions can be anywhere between 1,300 to 2,200 F.) 

To withstand that heat, Parker Solar Probe is outfitted with a cutting-edge heat shield, called the Thermal Protection System. This heat shield is made of a carbon composite foam sandwiched between two carbon plates. The Sun-facing side is covered with a specially-developed white ceramic coating, applied as a plasma spray, to reflect as much heat as possible.

The heat shield is so good at its job that even though the Sun-facing side of the shield will be at 2,500 F, the instruments in its shadow will remain at a balmy 85 F.

Parker Solar Probe Keeps its Cool

Several other designs on the spacecraft help Parker Solar Probe beat the heat. 

Parker Solar Probe is not only studying the Sun – it’s also powered by it. But even though most of the surface area of its solar arrays can be retracted behind the heat shield, even that small exposed segment would quickly make them overheat while at the Sun.  

To keep things cool, Parker Solar Probe circulates a single gallon of water through its solar arrays. The water absorbs heat as it passes behind the arrays, then radiates that heat out into space as it flows into the spacecraft’s radiator. 

It’s also important for Parker Solar Probe to be able to think on its feet, since it takes about eight minutes for information to travel between Earth and the Sun. If we had to control the spacecraft from Earth, by the time we knew something went wrong, it would be too late to fix it. 

So Parker Solar Probe is smart: Along the edges of the heat shield’s shadow are seven sensors. If any of these sensors detect sunlight, they alert the central computer and the spacecraft can correct its position to keep the sensors – and the rest of the instruments – safely protected behind the heat shield.

Over the course of its seven-year mission, Parker Solar Probe will make 24 orbits of our star. On each close approach to the Sun, it will sample the solar wind, study the Sun’s corona, and provide unprecedentedly close up observations from around our star – and armed with its slew of innovative technologies, we know it will keep its cool the whole time. 

Parker Solar Probe launches summer 2018 on its mission to study the Sun. Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

SpaceTime 20181010 Series 21 Episode 80 is now out

SpaceTime covers the latest news in astronomy & space sciences.

The show is available as a free twice weekly podcast through Apple Podcasts (itunes), Stitcher, Google Podcast, Pocketcasts, SoundCloud, Bitez.com, YouTube, Audio Boom, your favourite podcast download provider, and from www.spacetimewithstuartgary.com

SpaceTime is also broadcast coast to coast across the United States on Science360 Radio by the National Science Foundation in Washington D.C. and around the world on Tune-In Radio.

SpaceTime daily news blog: http://spacetimewithstuartgary.tumblr.com/ SpaceTime facebook: www.facebook.com/spacetimewithstuartgary SpaceTime Instagram @spacetimewithstuartgary SpaceTime twitter feed @stuartgary SpaceTime YouTube: https://www.youtube.com/c/SpaceTimewithStuartGary

Today’s stories…

Another lander touches down on the asteroid Ryugu Japan’s Hyabusa2 spacecraft has successfully deployed a third lander rover onto the rugged boulder strewn surface of the asteroid Ryugu – located some 300 million kilometres from Earth.

New Neutron Star discovery challenges existing theories Existing theories about Neutron stars have taken a blow with astronomers detecting radio jets emanating from a neutron star with a strong magnetic field.

New sub-atomic particles discovered at the super collider Physicists have discovered two new sub atomic particles with hints of a possible third.

Intergalactic stars flying towards the Milky Way Astronomers have discovered dozens of stars flying through intergalactic space heading towards the Milky Way Galaxy.

The Science Report Russia widely condemned over a series of cyber-security attacks. Users demanding higher purity types of ecstasy, crystal methamphetamine, and cocaine. Australia records its driest September on record. Wireless broadband connections the most popular means of accessing the Internet. Alex on tech Prince Charles gives the thumbs down to artificial intelligence.

Last Saturday’s show….

Opportunity still silent Scientists are increasing the frequency of commands being sent to the still silent Opportunity Mars rover on the surface of the red planet.

Neutrino experiment records its first tracks The world’s largest liquid-argon neutrino detector has just recorded its first particle tracks.

One hundredth Ariane 5 launch Arianespace has successfully carried out its 100th Ariane 5 launch.

October Skywatch A busy month with three meteor showers in October–the Draconids, the Taurids and the Orionids.

The Science Report A new class of antibiotics to combat the growing problem of deadly multi-drug resistant bacteria. New solar flow battery that both soaks up sunlight and store it as chemical energy for later use. How bombing air raids during World War Two affected the ionosphere. Warnings that industries dominated by the opposite sex tend to have higher rates of divorce.

SpaceTime Background SpaceTime is Australia’s most respected astronomy and space science news program. The show reports on the latest stories and discoveries making news in astronomy, astrophysics, cosmology, planetary science, galactic and stellar evolution, physics, spaceflight, and general science. SpaceTime features interviews with leading Australian scientists about their latest research. The show is broadcast coast to coast across the United States by the National Science Foundation on Science360 Radio and around the world on Tune in Radio. SpaceTime is available in Australia as a twice weekly podcast which averages around three million downloads annually. It’s hosted on line through Bitez.com on all major podcast platforms. SpaceTime began life in 1995 as ‘StarStuff’ on ABC NewsRadio. Stuart Gary created the show while he was NewsRadio’s Science Editor and evening News anchor. Gary wrote, produced and hosted the program, consistently achieving 9 percent of the Australian radio audience share - according to Neilsen ratings survey figures for the five major Australian metro markets (Sydney, Melbourne, Brisbane, Adelaide, & Perth). The StarStuff podcast was hosted by ABC Science on line achieving over 1.3 million downloads annually. Sadly, the popular program was axed in 2015 during ABC budget cuts. Rather than remain with the ABC, Gary resigned to continue producing the show independently and rebranding it as SpaceTime. The first episode of SpaceTime was broadcast on February 8th 2016 and the show has been in continuous production ever since. SpaceTime now reaches an audience almost three times greater that it achieved as StarStuff and continues to grow.

This image is beautiful, and closer to my heart because I have done a field study at NRAO. Such an incredible experience!

The W50 supernova remnant in radio (green) against the infrared background of stars and dust (red).

Credit: NRAO/AUI/NSF, K. Golap, M. Goss; NASA’s Wide Field Survey Explorer (WISE).

Crew Safe After Soyuz Launch Abort

NASA astronaut Nick Hague and Russian cosmonaut Alexey Ovchinin are in good condition following an aborted launch of their Soyuz spacecraft.

The Soyuz MS-10 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan to the International Space Station at 4:40 a.m. EDT Thursday, October 11 (2:40 p.m. in Baikonur) carrying American astronaut Nick Hague and Russian cosmonaut Alexey Ovchinin. Shortly after launch, there was an anomaly with the booster and the launch ascent was aborted, resulting in a ballistic landing of the spacecraft. Search and rescue teams were deployed to the landing site. Hague and Ovchinin are out of the capsule and are reported to be in good condition.

Note: This video is edited for length, but includes the launch, the initial report of the issue, and the confirmation that the crew landed safely.

My condolences to the people of France.

Terrorism has once again shown it is prepared deliberately to stop at nothing in creating human victims. An end must be put to this. As never before, it is vital to unite forces of the entire world community against terror.

I believe that the world will know the blessing of peace only when the love for power is overthrown by the power of love.

To all the people of France, may the force be with you during these tough vicious times.

PC: shirtshovel

NGC 3576, Statue of Liberty Nebula

Hayabusa2: Wide-angle navigational images of asteroid Ryugu, taken today as the probe descended temporarily to just 5km from the asteroid’s surface. These were originally posted to the probe’s Twitter feed.

Every. Damn. Time. 🙄🤦🏻‍♀️

my gym coach: and now, plank

me: hoe don't do it

my brain: planck's constant, 6.63 x 10-34 m2kg/s

me: oh my god

The NASA/ESA Hubble Space Telescope captures the iridescent tapestry of star birth in a neighbouring galaxy in this panoramic view of glowing gas, dark dust clouds, and young, hot stars.

Credit: NASA/ESA and the Hubble Heritage Team (AURA/STScI/HEIC)