ΕΚΤΑΤΟ! ΑΣΤΕΡΟΕΙΔΗΣ ΕΤΟΙΜΑΖΕΤΑΙ ΝΑ ΧΤΥΠΗΣΗ ΤΗΝ ΓΗ ΣΗΜΕΡΑ!---Asteroid? Rocket Stage? Whatever it is, WT1190F Plunges to Earth Tonight

Asteroid? Rocket Stage? Whatever it is, WT1190F Plunges to Earth Tonight

by BOB KING on NOVEMBER 12, 2015

A short animation (spanning about 10 minutes) captured by Ernesto Guido on Nov, 12, 2015. WT1190F is the star-like object at the center. Credit: Ernesto Guido

No one’s 100% certain what WT1190F is — asteroid or rocket stage — but we are certain it will light up like a Roman candle when it re-enters Earth’s atmosphere around 6:20 Universal Time (12:20 a.m. CST) tomorrow morning Nov. 13. 

Animation by Jost Jahn of WT1190F’s final hours as it races across the sky coming down off the coast of Sri Lanka

As described in an earlier story at Universe Today, an object discovered by the Catalina Sky Survey on Oct 3rd and temporarily designated WT1190F is expected to burn up about 60 miles (100 km) off the southern coast of Sri Lanka overnight. The same team observed it twice in 2013. Based upon the evolution of its orbit, astronomers determined that the object is only about six feet (2-meters) across with a very low density,  making it a good fit for a defunct rocket booster, possibly one used to launch either one of the Apollo spacecraft or the Chinese Chang’e 3 lander to the Moon.

Below a plot of the last three orbits of WT1190F. The small red circle is the Earth. For scale, the large green circle is the orbit of the Moon. Notice that its final orbit takes straight into Earth. Credit: Bill Grey / Project Pluto

Additional observations of WT1190F have been made in the past few days confirming its re-entry later tonight. Checking the latest predictions on Bill Grey of Project Pluto’s page, the object will likely be visible from Europe about an hour before “touchdown”. To say it will be moving quickly across the sky is an understatement. Try about 3 arc minutes per second or 3° a minute! Very tricky to find and track something moving that fast.

Three 90-second exposures showing WT1190F zipping across the Rosette Nebula taken on Nov. 11, 2015 at the Konkoly Observatory in Hungary. Credit: Krisztián Sárneczky

58 minutes later, in the minute of time from 6:18 to 6:19 UT,  WT1190F will move one full hour of right ascension and plummet 34° in declination while brightening from magnitude +8 to +4.5. If you’d like to attempt to find and follow the object, head over to JPL’s Horizons site  for the latest ephemerides and orbital elements. At the site, make sure that WT1190F is in the Target Body line. If not, click Change and search for WT1190F in the Target Body field at the bottom of the window. More updates will be at Bill Grey’s site.

Because the mystery object’s arrival has been fairly well publicized, I hope to update you with a full report and photos first thing tomorrow morning. Like many of you, I wish I could see the show!

Το αρχαιότερο ελληνικο γνωστό τραγούδι!--The oldest known GREEK song!

Η επιτύμβια στήλη ανακαλύφθηκε το 1883 στην ((τουρκική)) πόλη Αϊδίνιο, όπως είναι το σύγχρονο όνομα των αρχαίων Τράλλεων. Μάλιστα, κατά τη διάρκεια της Μικρασιατικής καταστροφής του 1922 η στήλη χάθηκε και πολλά χρόνια αργότερα ξαναβρέθηκε σε έναν κήπο τουρκικού σπιτιού. Η ιδιοκτήτρια του σπιτιού είχε κόψει τη βάση της στήλης για να την χρησιμοποιήσει ως βάζο για λουλούδια. Σήμερα φυλάσσεται στο Εθνικό Μουσείο της Δανίας στην Κοπεγχάγη. Πιστά αντίγραφά του υπάρχουν σε διάφορα μουσεία.

Ο Σείκιλος έγραψε το τραγούδι του μετά το 200 π.Χ. σε επιτύμβια κυλινδρική στήλη που έχει ύψος 40 εκατοστά και περιέχει στην κοινή ελληνική της ελληνιστικής εποχής ένα επίγραμμα δώδεκα λέξεων και ένα μέλος (τραγούδι) δεκαεφτά λέξεων μαζί με τη μουσική του. Στην κορυφή της στήλης, το επίγραμμα αναφέρει τον άνθρωπο που το έγραψε, καθώς και το σκοπό για τον οποίο το έγραψε:

ΕΙΚΩΝ Η ΛΙΘΟΣ ΕΙΜΙ. ΤΙΘΗΣΙ ΜΕ ΣΕΙΚΙΛΟΣ ΕΝΘΑ ΜΝΗΜΗΣ ΑΘΑΝΑΤΟΥ ΣΗΜΑ ΠΟΛΥΧΡΟΝΙΟΝ (Εγώ η πέτρα είμαι μια εικόνα. Με έβαλε εδώ ο Σείκιλος ως διαχρονικό σήμα αθάνατης μνήμης).

Στη μέση υπάρχουν οι στίχοι του τραγουδιού μαζί με τα σύμβολα της μελωδίας, η οποία είναι του λεγόμενου φρυγικού τύπου:

ΟΣΟΝ ΖΗΣ ΦΑΙΝΟΥ,
ΜΗΔΕΝ ΟΛΩΣ ΣΥ ΛΥΠΟΥ.
ΠΡΟΣ ΟΛΙΓΟΝ ΕΣΤΙ ΤΟ ΖΗΝ,
ΤΟ ΤΕΛΟΣ Ο ΧΡΟΝΟΣ ΑΠΑΙΤΕΙ.

Μετάφραση
Όσο ζεις λάμπε,
καθόλου μη λυπάσαι.
Για λίγο διαρκεί η ζωή,

ο χρόνος απαιτεί την πληρωμή του.

Στο κάτω μέρος της στήλης αναγράφεται η αφιέρωση ΣΕΙΚΙΛΟΣ ΕΥΤΕΡΠΗΙ (Ο Σείκιλος στην Ευτέρπη), αλλά δεν γίνεται κατανοητό εάν πρόκειται για τη σύζυγο, την ερωμένη, τη φίλη, την αδελφή ή την κόρη του, ή και απλώς τηνΜούσα της μουσικής. Το μήνυμα αυτό αντιστοιχεί στο επικούρειο απόφθεγμα «όσο ζούμε πρέπει να χαιρόμαστε όπως οι θεοί» γιατί ο θάνατος είναι το τέλος και δεν υπάρχει συνέχεια. Εμφανώς επικούρεια είναι όλα τα αναφερόμενα συστατικά του μέλους: η ηδονή της ζωής, η αταραξία, καθώς και το τελικό όριο της ζωής, ο θάνατος.

Η επιτύμβια στήλη ανακαλύφθηκε το 1883 στην τουρκική πόλη Αϊδίνιο, όπως είναι το σύγχρονο όνομα των αρχαίων Τράλλεων. Μάλιστα, κατά τη διάρκεια της Μικρασιατικής καταστροφής του 1922 η στήλη χάθηκε και πολλά χρόνια αργότερα ξαναβρέθηκε σε έναν κήπο τουρκικού σπιτιού. Η ιδιοκτήτρια του σπιτιού είχε κόψει τη βάση της στήλης για να την χρησιμοποιήσει ως βάζο για λουλούδια. Σήμερα φυλάσσεται στο Εθνικό Μουσείο της Δανίας στην Κοπεγχάγη. Πιστά αντίγραφά του υπάρχουν σε διάφορα μουσεία.

The melody[edit]

On the inscription and above each line of the lyrics (transcribed here in polytonic script), there is a line with letters and signs for the tune:^[6]

The Seikilos "score"

Translated into modern musical notation, the tune is something like this:

The Seikilos epitaph melody

Scholarly views[edit]

	Epitaph of Seikilos MENU 0:00 Melody sung in an approximation ofKoine Greek pronunciation and in modern popular vocal style.
Problems playing this file? See media help.

	Melody played using General MIDI synthesis (MIDI file format). (info)
Problems listening to this file? See media help.

Although the transcription of the melody is unproblematic, there is some disagreement about the nature of the melodic material itself. There are no modulations, and the notation is clearly in the diatonic genus, but while it is described on the one hand as being clearly in the diatonic Iastian tonos,^[7] in other places it is said to "fit perfectly" within Ptolemy's Phrygian tonos,^[8] since the arrangement of the tones (1 ½ 1 1 1 ½ 1 [ascending]) "is that of the Phrygian species" according to Cleonides.^[9] The overall note series is alternatively described as corresponding "to a segment from the Ionian scale".^[10] Another authority says "The scale employed is the diatonic octave from e to e(in two sharps). The tonic seems to be a; the cadence is a f♯ e. This piece is … [in] Phrygic (the D mode) with its tonic in the same relative position as that of the Doric.^[1] Yet another author explains that the difficulty lies in the fact that "the harmoniai had no finals, dominants, or internal relationships that would establish a hierarchy of tensions and points of rest, although themese (“middle note”) may have had a gravitational function". Although the epitaph's melody is "clearly structured around a single octave, … the melody emphasizes the mese by position … rather than the mese by function".^[11]

Date[edit]

The find has been dated variously from around 200 BC to around AD 100, but the first century AD is the most probable guess.^[12] The date of the inscription itself is also a matter of some debate. One authority states that on grounds of paleography the inscription can be "securely dated to the first century C.E.",^[5] while on the same basis (the use of swallow-tail serifs, the almost triangular Φ with prolongation below, ligatures between N, H, and M, and above all the peculiar form of the letter omega) another is equally certain it dates from the second century AD, and makes comparisons to dated inscriptions of 127/8 and 149/50 AD.^[13]

Musical system[edit]

Although the material on the Seikilos stele is sparse, it indicates that the Greeks had developed a musical system in the third or fourth century BC. It was probably only used by professional composers and choir leaders, while others learned the tunes by listening to them.^{[citation needed]} Texts of plays, regardless of type, were often copied without music, so the lyrics with music like that of the Seikilos epitaph are extremely rare.^{[clarification needed]} There is no evidence that the Greek musical system survived into the Middle Ages, but texts from Byzantine times and the early Renaissance have added notations after the Greek system.^[vague]

Yet, despite claims that songs from ancient civilisations have been recovered – found carved into walls or impressed into clay tablets – it is nearly impossible to reconstruct ancient lyrics and melodies.

Arguably the earliest-known song, with both melody and lyrics recorded intact, from antiquity is the ‘Epitaph of Seikilos’, a funerary piece intended for voice and the string instrument, the lyre.

The Ancient Greek composition, thought to have been written in the first century AD, exists on a marble stele, which was discovered in 1883 in modern-day Turkey.

To go along with its melancholic melody (which can be heard here), are these sobering lyrics:

While you live, shine
Do not suffer anything at all
life exists only for a short while
and time demands its toll.

World's only JetPack flies in New York

JB-9 jetpack makes spectacular debut flying around Statue of Liberty

The dream of personal flight took a great leap forward last week as Jetpack Aviation unveiled its JB-9 jetpack in spectacular fashion. Lifting off from a boat, inventor and aviator David Mayman flew the powerful, agile JB-9 around the Statue of Liberty, pausing to salute and pirouette before touching back down. Running on kerosene and using two vectored jet engines, the JB-9 can reach high speeds and altitudes and offers a flight time over 10 minutes, depending on pilot weight. We spoke at length with Mayman to discover how the JB-9 works and how long it'll be before we can buy one.

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It’s 2015. Where’s my damn jetpack?

Believe it or not, people have been trying to build a jetpack for nearly a hundred years now. A portable, powerful device you can strap to your back, fire up and take to the skies for true freedom in three dimensions.

Things must have looked very positive in the 1960s when Bell’s Rocketbelt made its public debut. Thats the kind of design you might remember from the 1984 Olympics opening ceremony in Los Angeles. These hydrogen peroxide rocket belts are compact, very cool to look at, and perform more or less as you’d expect a jetpack to. Unfortunately they’re also difficult to fly, the fuel is extremely pricey and it runs out so quickly that you’re limited to about 30 seconds of flight.

More recently, you’ve got the Martin Jet Pack, which offers more than 30 minutes of flight endurance, which has safety systems built in, and which you should soon be able to actually buy for a couple of hundred grand. But it’s enormous, about as portable as a piano, and you can’t strap it to your back and walk anywhere.

There’s Yves Rossy, the Swiss Rocketman who soars through the sky on a jet-powered wing at more than 300 km/h and performs all manner of incredible aerobatics. But that’s likewise a pretty big chunk of kit, it needs to be launched at speed from a plane that’s already in the air, and at the end of the day you’re about as likely to get a chance to fly one yourself as you are to visit the moon.

Then there's Troy Hartman's parafoil jetpack, which was an accidental discovery in the process of trying to build a jet wing similar to Rossy's. But it needs a strong enough breeze to lift and fill the parachute in order to get going, and it just doesn't really look the part.

All of which is a long-winded way to point out that this is a really difficult problem to solve, so when you see the video of the JB-9below, you’re looking at a significant achievement and a milestone in personal flight.

Introducing Jetpack Aviation

Jetpack Aviation is the brainchild and passion project of Australian businessman David Mayman. "I’ve been flying it off the public radar for some time," Mayman told us this morning. "It was time to bring it out of the closet, so to speak. I’ve spent my life in software and mining and fairly sensible occupations, but my overriding passion has been to build a jetpack, since I was very young. Nelson Tyler and I got together 10 years ago –he’s an extraordinary engineer and inventor based in Hollywood. And that’s really what’s made it possible."

In Tyler, Mayman found the perfect partner. Tyler had worked on the Rocketbelt flight project at the 1984 Olympics, and for the last 45 years had been every bit as obsessed as Mayman with the idea of building a proper portable jetpack with decent endurance that anyone could fly. And the JB-9 jetpack they have just demonstrated is really the first design that meets most people’s expectations of what a real jetpack should be.

The JB-9 jetpack

"It’s a jet and a backpack," says Mayman, alluding to the fact that many competitors are, well, neither. "It can take off vertically. With no fuel in it, I’ve jogged about a kilometer with it strapped to my back. Even full of fuel I’ve jogged a few hundred metres. There’s a large suitcase that our whole JB-9 will fit into. It’ll fit in the back of a car. The little handles fold up but that’s about it."

And the total endurance for the JB-9? "10 minutes plus, depending on pilot weight," says Mayman. "For the technically minded, it also depends a little bit on temperature, altitude and that kind of thing, but that’s by no means as significant as the total pilot weight."

The device can carry a total of 10 gallons of fuel, which it burns at around a gallon a minute. And the fuel itself is simple: kerosene. Cheap, safe and easily available from your local service station.

The JB-9 uses a carbon-fiber corset that straps to the pilot’s back, with the majority of the "backpack" section carrying fuel. Mounted to each side is a small jet turbine engine that provides upward thrust. These engines mix ambient air with their exhaust gases to bring temperatures down to a comfortably warm airstream, but Mayman still wears a fireproof Nomex suit just in case: "The exhaust temperature actually declines really quickly. It’s still warm, don’t get me wrong. On a cold night it’s exactly what you want running next to you, but it’s not something that sets the ground on fire."

How to fly the JB-9 jetpack

"On the left hand I’ve got a twistgrip controlling yaw," says Mayman. "If I turn my hand to the left, I spin to the left. You’ll see some little yaw vanes at the bottom of each engine, a little cup that tilts backward and forward. They’re not on servo motors, they’re on push/pull cables. That’s how we control yaw. They’re always going in the opposite direction to each other, so if you vector the right engine forward, the left one goes backward and you get that yaw rotation.

"On the right I’ve got a fly by wire throttle driving the engines. That actually works back to front compared to a motorcycle throttle. Going back into the 1960s, the way Bell had it set up, you turn your hand inwards to develop thrust. Ours works the same way."

The twistgrips sit on the end of levers, which can be pushed up and down to tilt the jet engines, either individually or together, says Mayman. "This makes our device more maneuverable than anything else out there right now. Rather than just vectoring the thrust, we’re vectoring the entire engine. They’re on a sort of gimbal arrangement. You’re not only moving the line of the thrust, you’re moving the centre of thrust. What it means effectively is that I can go from a standing start, get up to a pretty high speed and stop on a dime, turn, spin, that sort of thing.

"To go forward or backwards, which requires pitch, effectively what I’m doing is pushing both handles down, that’ll make me go forward. Pulling them up, or actually allowing them to come up, because that’s what they want to do under thrust, that’ll make me go backwards. Or more likely, just slow down from speed. The whole thing is completely manual at the moment, it’s literally a pair of levers tilting the engines.

"You don’t need much roll. I’ve got a lot of time in helicopters and it’s similar to that. Once you start a roll in a helicopter using lateral cyclic, the helicopter will basically follow that, you don’t need to push it. It’s the same on this. It’s kind of kinesthetic, once you start a roll by shifting your body one way and pushing your arms down a little to the left, it’ll continue that rolling motion to the left. So it doesn’t need very much but there’s roll control in that sense."

The JB-9 already has some pretty fearsome capabilities. "The New York video was showing a hundredth of what this thing is capable of and what I’ve done, but clearly I was being a bit cautious on the day," Mayman tells us. "We’ve limited JB-9 to the required standards, which is 55 knots, or just over 100 kilometers per hour. JB-10, which we’ve already got a prototype running for and which I’ve already flown, will be capable of well over 200 kilometers per hour. That’s horizontal speed.

"Vertical speed depends more on your fuel payload. You’d probably get an initial climb rate of 500-1000 feet a minute. As your fuel burns off, you get extraordinary vertical rates. You can go up a thousand feet a minute. Being turbine engines, they don’t run out of performance as the air thins. They’ll just keep going, they’re compressing the air like a turbocharger. You could keep going up to 10,000 feet. But I won’t be putting my hand up for that one immediately!"

When can you buy and fly your own jetpack?

Mayman says the current JB-9 design is perfectly legal to sell and fly: "Technically we could start selling them in the ultralight category tomorrow. It couldn’t hold more than 5 US gallons of fuel (meaning a flight time around 5 minutes), and there’s certain restrictions about where you could fly them.

"It would be pretty expensive, but there are many people in the world that have the resources to do something like that. They don’t even need to have a license under the ultralight category, and there’s no certification of the device itself."

So would he sell you one? "Right now, I wouldn’t. We’ve had some people in the office writing some pretty large multi-million dollar cheques in front of us and we’ve said no. I want to be sensible about who’s got their hands on this thing. We have certain responsibilities here and in other parts of the world with countries that are friendly to the situation I’m in at the moment – expectations that we don’t go selling them willy-nilly.

"I’d wanna feel like we have an infrastructure to train them … we could technically just send them the unit in a box and say 'good luck' but it’s not necessarily going to end well if you’re doing 200 km/h, 5 feet off the ground, you know? It could be a monster. But we’re working on it. We’ll get there."

Before a JB series machine goes to market, the next step for Jetpack Aviation is to give the device a brain and the ability to stabilize itself – a goal Mayman considers well within reach. "The sensors, they’re a dime a dozen. Accelerometers, solid state gyros and whatnot, every iPhone has what we need, except of course we go for the $5,000 mil-spec ones.

"What we’re gonna do is build in little linear actuators so the computer can mechanically drive these arms. We’re still gonna be moving the arms up and down, but it’ll be driven by computer. And people can override that if they want to, it’ll be kind of like a helicopter autopilot, you’ll be able to push through it.

"One day we’ll get to the point where you could strap it on, and push the green button, and it’ll come up into a hover by itself. You won’t need any training. This stuff is not massively clever any more and it’s certainly not heavy. It’s just a matter of time and money."

So a consumer model stabilized jetpack is definitely in the works. Depending on jurisdiction, you might not even need a basic pilot’s course to fly one. And in the meanwhile, you might still get the chance to see the JB series units in action in a town near you.

"One of the things we’re looking at right now with a very well known brand is putting together a little race series," says Mayman. "We’ll build the packs, we’ll train them properly, the series can travel from place to place and I think people would very much enjoy seeing them. It’s one thing to watch it on a video, but when you’re standing in front of one of these things and they launch in front of you, it’s just amazing."

Amazing indeed. A properly functioning, safe, portable jetpack will have all sorts of practical applications and commercial use cases. But more importantly, they’ll just be massively cool. If airplanes and helicopters are like the cars of the sky, then jetpacks will be like motorcycles, putting you in the middle of the scenery and enhancing the emotion and immersion of the experience. Sign me up.

Source: Jetpack Aviation

Note: If you want to keep track of the JB-9's progress, keep an eye on the Own the Sky Facebook page. A film team from Firelight Productions and Paper Bark Films has been following Mayman's progress for the last 10 years to produce a documentary. Should be a cracker!