SpaceTime 20181010 Series 21 Episode 80 Is Now Out

Eris is the most massive and second-largest dwarf planet in the known Solar System. Eris was discovered in January 2005 by a Palomar Observatory-based team led by Mike Brown, and its identity was verified later that year. In September 2006 it was named after Eris, the Greek goddess of strife and discord. Eris is the ninth most massive object directly orbiting the Sun, and the 16th most massive overall, because seven moons are more massive than all known dwarf planets.

Eris is a trans-Neptunian object (TNO) and a member of a high-eccentricity population known as the scattered disk. It has one known moon, Dysnomia. (Eris and Dysnomia are seen in the first image).

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Cygnus Shell Supernova Remnant W63 via NASA https://ift.tt/2znmGCd

I love this! Our SPS club is building a memorial to Cassini, and it should be finished and installed by March!

Ultra-Close Orbits of Saturn = Ultra-Cool Science

On Sept. 15, 2017, our Cassini spacecraft ended its epic exploration of Saturn with a planned dive into the planet’s atmosphere–sending back new science to the very last second. The spacecraft is gone, but the science continues!

New research emerging from the final orbits represents a huge leap forward in our understanding of the Saturn system – especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised. How did they form? What holds them in place? What are they made of?

Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings from Cassini’s Grand Finale. That’s when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.

Knowing Cassini’s days were numbered, its mission team went for gold. The spacecraft flew where it was never designed to fly. For the first time, it probed Saturn’s magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the engineering push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.

Many more Grand Finale science results are to come, but today’s highlights include:

Complex organic compounds embedded in water nanograins rain down from Saturn’s rings into its upper atmosphere. Scientists saw water and silicates, but they were surprised to see also methane, ammonia, carbon monoxide, nitrogen and carbon dioxide. The composition of organics is different from that found on moon Enceladus – and also different from those on moon Titan, meaning there are at least three distinct reservoirs of organic molecules in the Saturn system.

For the first time, Cassini saw up close how rings interact with the planet and observed inner-ring particles and gases falling directly into the atmosphere. Some particles take on electric charges and spiral along magnetic-field lines, falling into Saturn at higher latitudes – a phenomenon known as “ring rain.” But scientists were surprised to see that others are dragged quickly into Saturn at the equator. And it’s all falling out of the rings faster than scientists thought – as much as 10,000 kg of material per second.

Scientists were surprised to see what the material looks like in the gap between the rings and Saturn’s atmosphere. They knew that the particles throughout the rings ranged from large to small. They thought material in the gap would look the same. But the sampling showed mostly tiny, nanograin- and micron-sized particles, like smoke, telling us that some yet-unknown process is grinding up particles. What could it be? Future research into the final bits of data sent by Cassini may hold the answer.

Saturn and its rings are even more interconnected than scientists thought. Cassini revealed a previously unknown electric current system that connects the rings to the top of Saturn’s atmosphere.

Scientists discovered a new radiation belt around Saturn, close to the planet and composed of energetic particles. They found that while the belt actually intersects with the innermost ring, the ring is so tenuous that it doesn’t block the belt from forming.

Unlike every other planet with a magnetic field in our Solar System, Saturn’s magnetic field is almost completely aligned with its spin axis. Think of the planet and the magnetic field as completely separate things that are both spinning. Both have the same center point, but they each have their own axis about which they spin. But for Saturn the two axes are essentially the same – no other planet does that, and we did not think it was even possible for this to happen. This new data shows a magnetic-field tilt of less than 0.0095 degrees. (Earth’s magnetic field is tilted 11 degrees from its spin axis.) According to everything scientists know about how planetary magnetic fields are generated, Saturn should not have one. It’s a mystery physicists will be working to solve.

Cassini flew above Saturn’s magnetic poles, directly sampling regions where radio emissions are generated. The findings more than doubled the number of reported crossings of radio sources from the planet, one of the few non-terrestrial locations where scientists have been able to study a mechanism believed to operate throughout the universe. How are these signals generated? That’s still a mystery researchers are looking to uncover.

For the Cassini mission, the science rolling out from Grand Finale orbits confirms that the calculated risk of diving into the gap – skimming the upper atmosphere and skirting the edge of the inner rings – was worthwhile.

Almost everything going on in that region turned out to be a surprise, which was the importance of going there, to explore a place we’d never been before. And the expedition really paid off!

Analysis of Cassini data from the spacecraft’s instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.

To read the papers published in Science, visit: URL to papers

To learn more about the ground-breaking Cassini mission and its 13 years at Saturn, visit: https://www.nasa.gov/mission_pages/cassini/main/index.html

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

VIDEO FROM THE SURFACE OF A COMET

This is truly incredible.

Details:

Remember Rosetta? That comet-chasing European Space Agency (ESA) probe that deployed (and accidentally bounced) its lander Philae on the surface of Comet 67P? This GIF is made up of images Rosetta beamed back to Earth, which have been freely available online for a while. But it took Twitter user landru79 processing and assembling them into this short, looped clip to reveal the drama they contained.

I want to be a fairytale ending.

(via Recycled Blog)

#dearMoon is an amazing project that I hope to see come to completion. 🖤

Japanese Billionaire purchases SpaceX colonial ship for circumlunar art project. (September 16, 2018)

Two years after the company announced that a private individual bought a Crew Dragon flight to the moon, SpaceX founder and chief designer Elon Musk revealed their identity Monday night, September 16. In a press conference held at the company’s Hawthorne, California headquarters, surrounded by newly-constructed Falcon 9 rockets, Musk announced that 42-year old Japanese Billionaire Yusaku Maezawa bought an entire BFR spaceship for a circumlunar mission slated to launch no earlier than 2023.

Maezawa - a 42-year old art collector and founder of Japan’s largest online fashion retail site - booked the flight as part of his #dearMoon project, which was also revealed at Monday night’s conference. “Ever since I was a kid, I have loved the moon. Just staring at the moon filled my imagination. It’s always there and has continued to inspire humanity. That is why I could not pass up this opportunity to see the moon up-close.”

#dearMoon

However, Maezawa does not plan on travelling to cislunar space alone - he intends on taking up to eight artists on a trip that aims to “inspire the dreamers in all of us.”

“What if Picasso had gone to the moon, or Andy Warhol, or Michael Jackson, or John Lennon, or Coco Chanel. There are so many artists with us today that I wish would create amazing works of art for humankind, for children of the next generation. And I wish very much that such artists could go to space, and see the moon up close and the Earth in full view and create works that reflect their experience.

#dearMoon aims to send up to eight artists as Maezawa’s guests on a six-day voyage around the moon. “These artists will be asked to create something after their return to Earth and these masterpieces will inspire the dreamer within all of us” Maezawa stated.

The billionaire entrepreneur had not decided on the specific amount of artists or the fields they will represent, but an accompanying promotional video for the project stated that they will “represent Earth” from various fields. These could include “painters, sculptors, photographers, musicians, film directors, fashion designers, architects, etc.”

Maezawa’s inspiration for the project stemmed from imagining his favourite painter - Jean-Michel Basquait, and the works he could have created had he seen the Moon up close. Referencing pop culture and music references ranging from Beethoven to Van Gogh and the Beetles, Maezawa stated that the moon has inspired countless works throughout the ages. “And with utmost love and respect for the moon, our planet’s constant partner, I named this project #dearMoon.” This will not be the first time that prominent Earth artists have come together to create lunar-inspired artwork. Although the artists themselves never left the planet, miniature facsimile copies of works created by Andy Warhol, Forrest Myers, Robert Rauschenberg and others were secretly installed by a Grumman employee on the Apollo 12 lunar module in 1969. The ‘Moon Museum’ - a ceramic wafter less than an inch in size hidden under the gold foil of the Lunar Module’s descent stage - was not disclosed publicly until the mission was already returning to the Earth following their lunar landing.

From the Earth to the Moon.

According to graphics presented at the press conference, Maezawa’s flight would last just under six days from launch to landing. The Big Falcon Spaceship would fly on a “free-return” trajectory around the moon, a flight profile which craft loop around the moon without entering orbit and return to Earth. Lunar gravity would maneuver the spacecraft in such a way that additional course corrections would not be necessary, providing the safest flight profile for a flyby. Apollo 13 flew a modified free-return trajectory following the explosion of an oxygen tank aboard the spacecraft in April, 1970. According to a SpaceX tweet late Monday evening, the company is expecting the BFS to fly as close as 125 miles to the Lunar surface.

During a question and answer session immediately following the announcement, Elon Musk stated that the projected 2023 launch date is not set in stone. “This is a ridiculously big rocket. It’s got so much advanced technology. It’s not 100% certain that we succeed in getting this to flight.” By comparison, the inaugural flight of the Falcon Heavy rocket was slated for late mid-2014 before slipping to the right nearly four years to February 2018.

Monday’s announcement also confirmed that Maezawa initially intended to perform the mission on the company’s Crew Dragon vehicle atop a Falcon Heavy rocket. SpaceX announced in February, 2017 that an unnamed individual paid a deposit for the flight, which was initially scheduled to launch in late 2018.

Immediately following Falcon Heavy’s test flight in February, 2018, SpaceX stated that the rocket was no longer being human-rated, putting the future of the mission in doubt until last week. Musk stated Monday that after modifying the capsule for deep space flight and circumlunar operations, there would only have been enough room for Maezawa and one additional person, not enough to fulfill the host’s desire for a variety of artists.

“If in doubt, go with Tintin.”

Monday’s announcement also presented the third variation of Musk’s Big Falcon Rocket since it was announced at the 2016 IAC in Guadalajara, Mexico.

The recent modifications reflect additional design work by the SpaceX teams to make the spaceship more aerodynamically stable during atmospheric landings and surface operations.

Whereas the previous versions of the Big Falcon Spaceship resembled a cylinder with two small delta wings, the new design features three equally-sized wings equidistant around the vehicles aft section. Two of the wings would be actuated control surfaces that would change orientation during various parts of planetary atmospheric entry. The third, according to Musk “is just a leg…it doesn’t serve any aerodynamic purpose.”

Two smaller fins near the nose of the ship actuate in tandem with the larger fins for further stability.

The design resembles the interplanetary ships of mid 20th-century science fiction, including the rocket from Belgian cartoonist Herge’s famous Tintin series. Musk even stated during the conference that he wanted to bias the BFR design towards the famous cartoon ship: “I love the Tintin rocket design. If in doubt, go with Tintin.”

Although Musk declined to comment on the amount of Maezawa’s deposit for the BFR circumlunar flight, he did state that “it will have a material effect on paying for the development” of the BFR system. Currently, only around 5% of SpaceX resources are spent on BFR, though Musk expects that to “change quite significantly in the years to come.”

He reiterated that the company’s top priorities are still NASA missions to the space station and commercial launches using the smaller Falcon 9 vehicle. The final major version of that rocket, the Block 5, made its first flight earlier in 2018. Once Crew Dragon flights begin on a regular basis - Musk did not state a specific time but likely to be in early 2019 - the company will shift their engineering talent more fully towards BFR. Musk also showed images of the BFR test article, including a cylindrical segment constructed at the company’s recently-purchased facility at the Port of Los Angeles. Watch the introductory video for #dearMoon below. Click here for a replay of SpaceX’s press conference introducing Maezawa and #dearMoon

P/c: SpaceX/#dearMoon

Cherenkov Radiation: When Electrons go Faster than the Speed of Light!

Well faster than light is an overstatement in the sense that it only happens in water. Basically the speed of light in water is 0.75c and although matter can be accelerated faster than that it is still below the speed of light in a vacuum. And that’s what basically causes the blue light or Chernenkov radiation, particles in a medium moving faster than the speed of light in that medium. 

How does that happen though? Well that is due to very excited neutrinos produced by the nuclear reactor colliding with the nuclei of the water that is surrounding it. The collision produces muons and electrons which have the resulting momentum faster than the speed that light can travel in water. Which in turn brings the electrons in the surrounding water atoms/molecules to a higher state, and when they return back to the ground state they emit light in the wavelength of the resulting momentum transfer from those excited particles. 

A common analogy is the sonic boom of a supersonic aircraft or bullet. The sound waves generated by the supersonic body propagate at the speed of sound itself; as such, the waves travel slower than the speeding object and cannot propagate forward from the body, instead forming a shock front. In a similar way, a charged particle can generate a light shock wave as it travels through an insulator.

More science and gifs on my blog: rudescience Gif made from: This video References: (x), (x). You can donate to support more science content on tumblr: here

55 Nights with Saturn

Brown Dwarfs, or “Failing Stars”, in the Orion Nebula. Image credit: NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team [3939x2955]

Nancy Grace Roman: NASA’s First Chief Astronomer via NASA https://ift.tt/2HmRxo3