Tag Archives: solar system

Oxygen on Rosettas Comet?

Ah, Rosetta, everyone’s favourite comet orbiter. The European Space Agency spacecraft that made a splash when it launched a lander onto the surface of Comet 67P is continuing to gather scientific data about its target, and today researchers announced an unexpected exciting discovery: molecular oxygen.

Rosetta’s ROSINA instrument—a mass spectrometer—detected O2 in the icy body’s coma, the cloud of gas and dust and other space stuff around Comet 67P/Churyumov-Gerasimenko. More exciting still, the researchers behind the find, which was published Wednesday in Nature, reckon the O2 is “primordial” oxygen, i.e. that it came from the cloud of molecules from which our Solar System was formed.

In a phone call, lead author André Bieler explained the team found a strong signal of oxygen early on in the Rosetta mission. “But we were so surprised that we initially didn’t know exactly what to do, or why it would be there, and what to do with it, so we decided to just keep monitoring for a while and see what happens.”

So why is it such an exciting find? Oxygen is the third most abundant element in the Universe, but while it’s been detected on some icy bodies in the Solar System, such as planets’ moons, it’d only ever been found in two interstellar clouds, and never in a comet. “No one was expecting it to be there,” said Bieler of the team’s finding.

Image: ESA/Rosetta/Navcam

The researchers observed 67P’s coma from September 2014 to March 2015 and saw a mean value of 3.8 percent molecular oxygen. What’s most important, however, is that this didn’t change as the comet continued onward and approached the Sun. Bieler explained that if the oxygen was only on the surface of the comet, they would have seen a decrease in the ratio of oxygen as the comet burned up and lost gas.

They write that “the preferred explanation of our observations is the incorporation of primordial O2 into the cometary nucleus.”

The presence of this oxygen in the comet’s nucleus suggests it was there when the comet was formed—and was therefore present in the molecular cloud that birthed the planets (as comets are basically leftover material).

“I think we have to kind of rethink our models.”

This adds to our knowledge of the early days of the Solar System—or at least questions it. “Current Solar System formation models do not predict conditions that would allow this to occur,” the authors note.

“One implication is that the accretion [the coming-together of cosmic dust to form the comet] had to be pretty gentle in order for the O2 in the ice to survive,” Bieler explained. “Otherwise I think we have to kind of rethink our models.”

Next, Bieler said they’d like to look at the southern hemisphere of 67P; these new measurements come from the northern hemisphere, as that side facing the Sun (Rosetta is powered by solar arrays). In the future, he said we should also look at other comets for comparison. The Rosetta mission is of course unique in its close targeting of a comet, and previous cometary missions haven’t had the technology capable of detecting oxygen.

The new paper is an example of one of the major scientific aims of the Rosetta mission: using the comet as something of an interstellar time capsule to explore the early days of our own Solar System.

Source: Motherboard

Sirius

In Ancient Egypt, Sirius was regarded as the most important star in the sky. In fact, it was astronomically the foundation of the Egyptians’ entire religious system. It was revered as Sothis and was associated with Isis, the mother goddess of Egyptian mythology. Isis is the female aspect of the trinity formed by herself, Osiris and their son Horus. Ancient Egyptians held Sirius in such a high regard that most of their deities were associated, in some way or another, with the star. Anubis, the dog-headed god of death, had an obvious connection with the dog star and Toth-Hermes, the great teacher of humanity, was also esoterically connected with the star.Sirius-1024x703

The Egyptian calendar system was based on the heliacal rising of Sirius that occurred just before the annual flooding of the Nile during summer. The star’s celestial movement was also observed and revered by ancient Greeks, Sumerians, Babylonians and countless other civilizations. The star was therefore considered sacred and its apparition in the sky was accompanied with feasts and celebrations. The dog star heralded the coming of the hot and dry days of July and August, hence the popular term “the dog days of summer”.

Several occult researchers have claimed that the Great Pyramid of Giza was built in perfect alignment with the stars, especially Sirius. The light from these stars were said to be used in ceremonies of Egyptian Mysteries.

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Star alignment with the Great Pyramid of Giza. Orion (associated with the god Osiris) is aligned with the King’s Chamber while Sirius (associated with the goddess Isis) is aligned with the Queen’s Chamber. A fascinating aspect of Sirius is the consistency of the symbolism and meanings attached to it. Several great civilizations have indeed associated Sirius with a dog-like figure and viewed the star as either the source or the destination of a mysterious force. In Chinese and Japanese astronomy, Sirius is known as the “star of the celestial wolf”. Several aboriginal tribes of North America referred to the star in canine terms: the Seri and Tohono O’odham tribes of the southwest describe the Sirius as a “dog that follows mountain sheep”, while the Blackfoot call it “Dog-face”. The Cherokee paired Sirius with Antares as a dog-star guardian of the “Path of Souls”. The Wolf (Skidi) tribe of Nebraska knew it as the “Wolf Star”, while other branches of knew it as the “Coyote Star”. Further north, the Alaskan Inuit of the Bering Strait called it “Moon Dog”.