UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN

Enceladus is blasting water into space from the jets at its southern pole. This makes it the ideal place to send a dedicated mission, flying the spacecraft through the plumes with life-detection instruments s. A new study suggests that a spacecraft must proceed carefully through the plumes, keeping its speed below 4.2 km/second (2,236 miles per hour). Using a specialized, custom-built aerosol impact spectrometer at these speeds will allow fragile amino acids to be captured by the spacecraft’s sample collector. Any faster, they’ll shatter, providing inclusive results.

One of the biggest surprises of the 20-year Cassini mission to the Saturn system was the discovery of the active geysers at Enceladus. At only about 500 km (310 miles) in diameter, the ice-covered Enceladus should be too small and too far from the Sun to be active. Instead, this little moon is one of the most geologically dynamic objects in the Solar System.

enceladusfountains_med.thumbnail.jpg — ***Geysers spew from Enceladus in this image from the Cassini spacecraft.***

Credit: NASA/Cassini mission.

Cassini’s stunning backlit images of this moon show plumes erupting in Yellowstone-like geysers, emanating from tiger-stripe-shaped fractures in the moon’s surface. The discovery of the geysers took on more importance when Cassini later determined the plumes contained water ice and organics. Since life as we know it relies on water and a source of energy, this small but energetic moon has been added to the short list of possible places for life in our Solar System.

During three of Cassini’s passes of Enceladus in 2008 and 2009, the spacecraft’s Cosmic Dust Analyser measured the composition of freshly ejected plume grains. The icy particles hit the detector target at speeds of 6.5–17.5 km/s, and vaporized instantly. While electrical fields inside the instrument were able to separate the various constituents of the resulting impact cloud for analysis, for a future mission, scientists would like to measure the particles in the plumes without completely vaporizing them.

Back in 2012, researchers from the University of California San Diego started working on a custom-built unique aerosol impact spectrometer, designed to study collision dynamics of single aerosols and particles at high velocities. Although it wasn’t built specifically to study ice grain impacts, it turns out this instrument might be exactly what planetary scientists are looking for to use at Enceladus, or even at Jupiter’s moon Europa, where there is growing evidence of active plumes of water vapor erupting from its surface.

Robert Continetti’s one-of-a-kind aerosol impact spectrometer was used in this experiment. Ice grains impact the microchannel plate detector (far right) at hypervelocity speeds, which can then be characterized in-situ.

Continetti and several colleague have now tested the device in a laboratory, showing that amino acids transported in ice plumes — like at Enceladus — can survive impact speeds of up to 4.2 km/s. Their research is published in The Proceedings of the National Academy of Sciences (PNAS).

“This apparatus is the only one of its kind in the world that can select single particles and accelerate or decelerate them to chosen final velocities,” said Robert Continetti, a professor from UC San Diego, in a press release. “From several micron diameters down to hundreds of nanometers, in a variety of materials, we’re able to examine particle behavior, such as how they scatter or how their structures change upon impact.”

From Cassini’s measurements, scientists estimate the ice plumes at Enceladus blast out at approximately .4 km/s (800 miles per hour). A spacecraft would have to fly at the right speeds to make sure the particles could be captured intact.

This composite image shows suspected plumes of water vapour erupting at the 7 o’clock position off the limb of Jupiter’s moon Europa. The plumes, photographed by Hubble’s Imaging Spectrograph, were seen in silhouette as the moon passed in front of Jupiter. Hubble’s ultraviolet sensitivity allowed for the features, rising over 160 kilometres above Europa’s icy surface, to be discerned. The water is believed to come from a subsurface ocean on Europa. The Hubble data were taken on January 26, 2014. The image of Europa, superimposed on the Hubble data, is assembled from data from the Galileo and Voyager missions.

Currently slated for launch in October of 2024, the Europa Clipper will travel to Jupiter (it will orbit Jupiter instead of Europa directly). It has a spectrometer on board to determine the composition of the surface and scan any plumes spouting water into space. Continetti and colleagues hope that their research will help determine what impact speeds would be optimal. But they also hope any future probes to Saturn might be able to identify a specific series of molecules in the ice grains that could point to whether life exists in the subsurface oceans of these moons. The challenge is having the molecules survive their speedy ejection from the moon and collection by the probe. They are confident their detector can do it.

“The implications this has for detecting life elsewhere in the Solar System without missions to the surface of these ocean-world moons is very exciting, but our work goes beyond biosignatures in ice grains,” said Continetti. “It has implications for fundamental chemistry as well. We are excited by the prospect of … looking at the formation of the building blocks of life from chemical reactions activated by ice grain impact.”

If nothing else catches your attention in the title then surely ‘hypernebula’ does! There are some amazing processes scattered around the cosmos, of particular interest are the fast radio bursts (FRB). These brief flashes of radiation happen without warning…until now. A team in the Netherlands have identified a second FRB as coming from within a hyper nebula – a dense and highly magnetised cloud of plasma that is illuminated by a powerful but unknown source!

FRBs are short outbursts of radio waves which last only a fraction of a second. They seem to originate from distant galaxies and one of the first to be discovered was FRB 20121102A. A second FRB source has been confirmed in the paper by the Netherlands team, this one known as FRB 20190520B. It was discovered by the FAST telescope in China and appears to be associated with hyper nebula just like the other repeating FRBs. Investigations go further revealing that it seems to be associated with a more constant source of radio waves.

The team followed up on their observations using the Very Long Baseline Interferometer (VLBI) which is a network of radio telescopes spread across Europe. Interferometry involves combining the signal form multiple dishes in different places. Using interferometry like this enables astronomers to capture images with a resolution far greater than they could achieve from the individual dishes.

Their observations from the team, led by Shivani Bhandari suggest the size of the host hyper nebula was of the order of 30 light years across, three times the size of the Crab Nebula. They were also able to measure the luminosity revealing it was around a hundred thousand times that of the Sun. This suggests the source may well be an extremely magnetic neutron star known as a magnetar (a neutron star is the highly compressed dense core of a star that went supernova).

Magentars are curious objects but one thing we do know is that they can produce a powerful stream of charged particles that create the surrounding nebulosity and it is from here that the radio source is being emitted. The magnetar inside FRB 20190520B is likely to be generating radio emissions which are prt of the driving force of the FRBs. The team have worked through their data and believe the magnetar to be around 4 and 1,900 years old making and the hyper nebula to be around 900 years old. Compared to most objects in the Universe, these are very very young.

One of the magic things about science is that there are often alternative theories. In the case of these repeating FRBs it may be that the hyper nebula is powered not by magnetism but by gravitation. In systems where there is a black hole or neutron star devouring matter from a nearby companion there could be a burst of radio waves as a result of powerful emissions.

Whether driven by magnetism or gravitational potential energy, these two FRBs are the first two that seem to repeat and are associated with a hyper nebula. Interestingly they are both hosted in low mass dwarf galaxies. They clearly show high levels of activity in young and energetic FRBs but it is interesring that even their older counterparts still emit radio bursts. There are many mysteries about FRBs but these latest observations hope to start to unravel their mysteries.

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