Diamond shaped asteroid one of 29k+ NEO’s detected

Japan’s space agency is preparing to attempt two landings on a diamond shaped asteroid called Ryugu. It is one of over 18,000 Near Earth objects that have now been detected.

Image result for ryugu asteroid

900 metre wide Ryugu asteroid

Ryugu has been described as ‘unusually shaped’ but I think it has become obvious that asteroids are a wide variety of seemingly random shapes, so no particular shape should be seen as unusual. It would be very unusual if they all looked similar,

Ryugu is a C-type asteroid. Asteroids (NASA):

C-type (carbonaceous): Includes more than 75 percent of known asteroids. Very dark with an albedo of 0.03-0.09.
Composition is thought to be similar to the Sun, depleted in hydrogen, helium, and other volatiles. C-type asteroids inhabit the main belt’s outer regions.

S-type (silicaceous): Accounts for about 17 percent of known asteroids. Relatively bright with an albedo of 0.10-0.22. Composition is metallic iron mixed with iron- and magnesium-silicates. S-type asteroids dominate the inner asteroid belt.

M-type (metallic): Includes many of the rest of the known asteroids. Relatively bright with an albedo of 0.10-0.18. Composition is apparently dominated by metallic iron. M-type asteroids inhabit the main belt’s middle region.

CNN:

Japan’s space agency will attempt to land a robotic unmanned landing craft on the surface of an asteroid 300 million-kilometers (186.4 million-miles) away from Earth next month.

The Hayabusa-2 spacecraft is currently orbiting around the diamond-shaped asteroid Ryugu, which it reached in June after a three-and-a-half year journey.

On September 21, the spacecraft will deploy the first of two landers onto the asteroid itself, where they will gather samples and conduct experiments. A second lander will be launched on October 3.

Later in the mission, the spacecraft itself will land on the asteroid after blowing a small crater in it using explosives, so samples can be gathered from below the object’s surface which have not been exposed to space.

JASA’s Asteroid Explorer “Hayabusa2” descended from its orbiting position (at a 20km altitude from Ryugu) to a minimum altitude of 851 m, on 6 -7 August 2018.

NASA has detected more than 29,000 Near Earth Objects, most over the last ten years, so the number is likely to keep increasing.

 

Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighborhood. Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter.

On a daily basis, about one hundred tons of interplanetary material drifts down to the Earth’s surface. Most of the smallest interplanetary particles that reach the Earth’s surface are the tiny dust particles that are released by comets as their ices vaporize in the solar neighborhood.

With an average interval of about 10,000 years, rocky or iron asteroids larger than about 100 meters would be expected to reach the Earth’s surface and cause local disasters or produce the tidal waves that can inundate low lying coastal areas. On an average of every several hundred thousand years or so, asteroids larger than a kilometer could cause global disasters.

No one should be overly concerned about an Earth impact of an asteroid or comet. The threat to any one person from auto accidents, disease, other natural disasters and a variety of other problems is much higher than the threat from NEOs. Over long periods of time, however, the chances of the Earth being impacted are not negligible so that some form of NEO insurance is warranted.

https://cneos.jpl.nasa.gov/about/basics.html

Possible interstellar object detected

NASA has announced they have detected an object in our Solar System that could be a visitor, possibly an interstellar comet.If this can be confirmed it would be the first proof that objects travel between stars.

I think it’s highly likely there are objects floating around untied to the gravity of one solar system, but given the vastness of Space the may be infrequent visitors – unless there’s a lot of them.

A2017U1

Diagram showing the path of A/2017 U1.
It made its closest approach to the sun on Sept. 9 and is now
zooming away 97,200 mph (156,400 km/h) relative to the sun.
Credit: NASA/JPL-Caltech

Space.com: Visitor from Far, Far Away: Interstellar Object Spotted in Our Solar System

A visitor from interstellar space has likely been spotted in our solar system for the first time ever.

The object, known as A/2017 U1, was detected last week by researchers using the Pan-STARRS 1 telescope in Hawaii.

“We have been waiting for this day for decades,” Paul Chodas, manager of the Center for Near-Earth Object Studies at the NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement.

“It’s long been theorized that such objects exist — asteroids or comets moving around between the stars and occasionally passing through our solar system — but this is the first such detection,” Chodas added. “So far, everything indicates this is likely an interstellar object, but more data would help to confirm it.”

Chodas and other researchers base this preliminary conclusion on A/2017 U1’s hyperbolic orbit — the fact that its path is taking the body out of the solar system. Other hyperbolic objects have been spotted before, but they were nudged onto escape trajectories by gravitational interactions with planets, said Matthew Holman, director of the Minor Planet Center in Cambridge, Massachusetts.

A/2017 U1 has had no such close encounters, Holman added. Outgassing could theoretically also push a comet onto a hyperbolic path, but that doesn’t seem to be the case with A/2017 U1, either, he said.

“All other plausible solutions don’t work out,” Holman told Space.com. “So you’re left with, this thing came from elsewhere.”

It’s unclear what exactly this thing is. When A/2017 U1 was first spotted, it was thought to be a comet (and was therefore given the moniker C/2017 U1). But further observations have revealed no evidence of a coma — the fuzzy cloud of gas and dust surrounding a comet’s core — so the object’s name was amended to its current asteroidal designation.

Perhaps it’s an Interstarship Enterprise.

Harmonics in Space

Visions of Harmony: Inspired by NASA’s Mission Juno

This Apple Music original celebrates the space agency’s groundbreaking journey to Jupiter—and the intersection between science and art.

While this is new harmony and space isn’t.

In 1619 Johannes Kepler publisahed Harmonices Mundi ( The Harmony of the World).

While medieval philosophers spoke metaphorically of the “music of the spheres”, Kepler discovered physical harmonies in planetary motion. He found that the difference between the maximum and minimum angular speeds of a planet in its orbit approximates a harmonic proportion. For instance, the maximum angular speed of the Earth as measured from the Sun varies by a semitone (a ratio of 16:15), from mi to fa, between aphelion and perihelion. Venus only varies by a tiny 25:24 interval (called a diesis in musical terms). Kepler explains the reason for the Earth’s small harmonic range:

The Earth sings Mi, Fa, Mi: you may infer even from the syllables that in this our home misery and famine hold sway.

The celestial choir Kepler formed was made up of a tenor (Mars), two bass (Saturn and Jupiter), a soprano (Mercury), and two altos (Venus and Earth). Mercury, with its large elliptical orbit, was determined to be able to produce the greatest number of notes, while Venus was found to be capable of only a single note because its orbit is nearly a circle.

At very rare intervals all of the planets would sing together in “perfect concord”: Kepler proposed that this may have happened only once in history, perhaps at the time of creation.

Kepler reminds us that harmonic order is only mimicked by man, but has origin in the alignment of the heavenly bodies:

Accordingly you won’t wonder any more that a very excellent order of sounds or pitches in a musical system or scale has been set up by men, since you see that they are doing nothing else in this business except to play the apes of God the Creator and to act out, as it were, a certain drama of the ordination of the celestial movements. (Harmonices Mundi, Book V).

Kepler discovers that all but one of the ratios of the maximum and minimum speeds of planets on neighboring orbits approximate musical harmonies within a margin of error of less than a diesis (a 25:24 interval). The orbits of Mars and Jupiter produce the one exception to this rule, creating the unharmonic ratio of 18:19. In fact, the cause of Kepler’s dissonance might be explained by the fact that the asteroid belt separates those two planetary orbits, as discovered in 1801, 150 years after Kepler’s death.

https://en.wikipedia.org/wiki/Harmonices_Mundi

 

Give cyclists space

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Practice what you preach?