This Artist’s Rendering Shows NASA’s Cassini Spacecraft Above Saturn’s Northern Hemisphere, Heading

Ham radio operator taking part in a field day

(Walter B. Lane. 1946)

European Spacecraft Pulls Alongside Comet “After 10 years and a journey of four billion miles, the European Space Agency’s Rosetta spacecraft arrived at its destination on Wednesday for the first extended, close examination of a comet. A six-minute thruster firing at 5 a.m. Eastern time, the last in a series of 10 over the past few months, slowed Rosetta to the pace of a person walking, about two miles per hour relative to the speed of its target, Comet 67P/Churyumov-Gerasimenko.”

Find out more from the nytimes.

Catching Up: Weather is weird... TWWN continues... 80 Meter woes...

-=> Weather is just plain odd around here. We’re supposed to get up to 7 inches of snow, but nothing so far. Here in town it’s actually pretty nice

Out in the country it’s a different story. Not snowing, but 30+ MPH winds are whipping the snow we do have into near blizzard like conditions in some areas. Went down to Stockbridge to my favorite coffee shop, Mud Creek, and if I hadn’t been driving the Jeep I don’t think I would have made it. Was bucking drifts a foot or more deep in some areas, and visibility was down to just a few feet in places.

Problem with the Jeep is I get overconfident. I was bashing along around 40 mph in four wheel drive, and nearly lost it when I nailed a 2 foot deep drift. Wouldn’t have been a problem if I’d been driving slow, but at 40 the front end wiped out and I nearly went sideways before I got it straightened out again. Needless to say, I slowed down a bit after that.

So, snow storms today, and by Thursday it’s supposed to be 40 degrees and raining.

Sigh…

Noticed they got the street dug up just down the road from the house here. Another water main break. Must be the fifth one we’ve had in town in the last two months. Feel sorry for the water utility guys. And I stocked up on bottled water just in case…

-=> Work on The World’s Worst Novel continues unabated. I’ve been having way too much fun with this thing. It’s an SF novel in the worst sense of the word, harking back to the old space opera days with ridiculous space battles, paying very little attention to whether or not the ‘science’ bears any relationship to actual physics. It’s also gotten very, very dirty. Well, not by modern standards. Compared to modern fiction it’s actually pretty mild, but for me… I keep wondering where this stuff comes from.

Curiously, I just realized that almost all of the main characters are female. The protagonist is female, her spouse is female, almost all the heads of government are female… Not sure why. Didn’t do it deliberately. 

-=> Amateur Radio stuff… I have, alas, been doing very little of late except listening. I’ve discovered that my Comet vertical antenna is total crap below about 20 meters or so, which is understandable when you look at how the thing is built. Most of the energy going into the thing, especially at lower frequencies, is never getting into the air. Frankly, it’s surprising I can get a decent SWR at all with the thing on the lower bands. I ran some generic calculations and if I got the formulas right (which I probably didn’t) if I put 200 watts into the thing down at 3.8 mHz I’m lucky if I get 20 out of it.

Weather has been so nasty I’ve never even tried to get the dipole up. For one thing, mounting it is going to be a problem. I’m going to have to put up some kind of mast to try to get the center of the thing up to around 35 feet, and then it’s going to have to be configured as an inverted V because there’s nothing I can hook the ends to.

I picked up a Gap Titan multi band vertical that I’m going to give a try. It’s far more efficient than the Comet and even better, I can finally use my big amplifier with it. It’s rated to handle 1,500 watts so I can finally fire up the Ameritron. If it works, that is. Considering Ameritron’s reputation, you never know what’s going to happen. I talked to a guy who used to sell the things and they’d go through every one before they sent it out because they were having a 25% failure rate straight form the factory. I looked it over carefully when I put it together and didn’t see any obvious issues, and it does come up in standby mode, but until I actually try using it, whether it’ll work or not is anyones guess.

From what I’ve been hearing, the Titan has some issues when it comes to tuning it to work on the various bands. One fellow I talked to told me he never could get the thing down to a reasonable SWR on 80 meters. Other people tell me they had no problems at all. So we’ll see. SWR doesn’t bother me that much. I’ve got a massive Palstar auto tuner that can handle up to 2,000 watts output to hang behind the Ameritron.

I really wish now that I’d spent a little bit more and gone for the solid state amplifier rather than the tube based one. The solid state amps are a lot easier to work with. They’re pretty much plug and play, just turn them on, select the band you want, and go. Tube amps are fussy, requiring a lot of fiddling whenever you change bands, even changing frequencies. It’s easy to mess them up and end up blowing a $300 tube. Still, it was almost a grand cheaper than the solid state amp I was looking at, so we’ll see.

NASA’s Cassini spacecraft is set to make its first dive through the narrow gap between Saturn and its rings on April 26, 2017. Because that gap is a region no spacecraft has ever explored, Cassini will use its dish-shaped high-gain antenna (13 feet or 4 meters across) as a protective shield while passing through the ring plane. No particles larger than smoke particles are expected, but the precautionary measure is being taken on the first dive. The Cassini team will use data collected by one of the spacecraft’s science instruments (the Radio and Plasma Wave Subsystem, or RPWS) to ascertain the size and density of ring particles in the gap in advance of future dives. As a result of its antenna-forward orientation, the spacecraft will be out of contact with Earth during the dive.

Below is a list of milestones expected to occur during the event, if all goes as planned:

– 5 p.m. PDT (8 p.m. EDT) on April 25: Cassini is approaching Saturn over the planet’s northern hemisphere in advance of its first of 22 planned dives through the gap between the planet and its rings.

– 1:34 a.m. PDT (4:34 a.m. EDT) on April 26: As it passes from north to south over Saturn, Cassini begins a 14-minute turn to point its high-gain antenna into the direction of oncoming ring particles. In this orientation, the antenna acts as a protective shield for Cassini’s instruments and engineering systems.

– 2 a.m. PDT (5 a.m. EDT) on April 26: Cassini crosses the ring plane during its dive between the rings and Saturn. The spacecraft’s science instruments are collecting data, but Cassini is not in contact with Earth at this time.

– No earlier than around midnight PDT on April 26 (3 a.m. EDT on April 27): Earth has its first opportunity to regain contact with Cassini as the giant, 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, listens for the spacecraft’s radio signal.

A once in a lifetime event visible every 75-76 years, Halleys comet returned in 1986. Halley is the only short-period comet that is clearly visible to the naked eye from Earth. It has been documented since 240 BC.

What are comets made of?

Why Neutrinos are so Weird

If you held out your thumb, every second about 65 billion neutrinos will pass through it. Besides photons, neutrinos are the most abundant particle in the universe, and by far the most unique.

The existence of the neutrino was first theorized by Wolfgang Pauli, after noticing how energy didn’t seem to be conserved in beta decay. He believed that the missing energy was being carried away by some “invisible” particle. He would later say “I have done a terrible thing, I have postulated a particle that cannot be detected.”

Although elusive, neutrinos can be detected, but it requires sensitive, and often massive detectors. After finding that neutrinos came in three types: electron, muon, and tau, a problem seemed to emerge. Electron neutrinos are created all the time in the Sun, as a by-product of nuclear fusion, but they would always find only a third of the total number of electron neutrinos they were expecting. So, where did the missing neutrinos go?

It turns out, neutrinos actually oscillate back and forth between the three different types. So, by the time the neutrinos from the Sun had reached Earth, two thirds of them have turned into muon and tau neutrinos. This discovery was especially surprising, since everyone thought neutrinos had no mass, like the photon. The fact that neutrinos could change in-flight implied that they could experience time, and due to special relativity, this means they must have mass.

While that mystery has been solved, we still have plenty to learn from these strange particles. Exactly how much do they weigh? Although we know they must have mass, they are so light, we can’t tell how much. Since they have no electric charge, is a neutrino its own anti-particle? Is there more than just three types of neutrinos? Answering these could help us uncover some of the biggest mysteries in physics today.

“JUNO PROBE MAKES HISTORY BY ENTERING JUPITER’S ORBIT AFTER FIVE-YEAR JOURNEY”

Last night, NASA and its Juno probe made history by entering a new probe in orbit around Jupiter. The Juno spacecraft, which had left Earth five years ago, finally entered Jovian orbit after a 35 minute rocket engine manoeuvre to slow down its approach to the planet and get caught by its gravity. Unlike other engine firings in the past, Juno’s manoeuvre was especially dangerous since no previous spacecraft had ever dared to pass so close to Jupiter; its intense radiation belts can destroy unprotected electronics. Luckily, since the probe was built like a tank with titanium shielding, a few minutes later, a sequence of tones transmitted from the spacecraft confirmed the braking manoeuvre had been a smashing success prompting wild cheering at NASA’s mission control in Pasadena, California. “All stations on Juno co-ord, we have the tone for burn cut-off on Delta B,” Juno Mission Control had announced. “Roger Juno, welcome to Jupiter.” Juno’s main objective is to sense Jupiter’s structure and chemistry to gather clues on how the gas giant formed some four-and-a-half-billion years ago. However, much of this observation will not take place until mid-October when Juno performs a second rocket engine burn to tighten its orbit to just 14 days. By then, Juno will be able to answer some interesting questions about the planet including where it formed  in the early Solar System and whether Jupiter has a solid core or a core made of compressed gas. After the mission ends, Juno is scheduled to dive into Jupiter’s atmosphere in February 2018 to ensure that there is no possibility of it crashing into and contaminating any of Jupiter’s large moons.

Read more about this fascinating story on: http://www.bbc.com/news/science-environment-36710768